git: use asyncssh as dulwich SSH vendor (#6797 )

* git: support client kwargs for auth in remote methods * tests: use docker for git/ssh server * move dulwich backend into subdir * add base sync<->async support * dulwich: add initial asyncssh SSH vendor * dulwich: use asyncssh as the default SSH vendor * add test for git over ssh * test read (fetch) over ssh * ci: re-enable ssh tests temporary workaround for #6788, #6789 * move async stubs into dvc.scm.asyn * tests: use sshfs and not dvc.fs.ssh * allow explicit 0-length read in asyncssh vendor
Dependabot/pip/pylint 2.11.1 (#6843 )
2026-11-02 15:28:30 +01:00 · 2021-10-21 14:36:45 +09:00 · 2021-10-20 14:34:10 +03:00 · 2021-10-20 12:41:00 +03:00 · 2021-10-20 15:57:44 +09:00 · 2021-10-20 11:25:00 +05:45
249 changed files with 5879 additions and 4412 deletions
@@ -0,0 +1,23 @@
+name: benchmarks
+on: [pull_request, workflow_dispatch]
+
+jobs:
+  bench:
+    name: run benchmarks
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-18.04]
+    steps:
+      - name: Cancel Previous Runs
+        uses: styfle/[email protected]
+        with:
+          access_token: ${{ github.token }}
+      - uses: actions/setup-python@v2
+        with:
+            python-version: 3.7
+      - uses: iterative/dvc-bench@master
+        with:
+            pytest_options: "-k 'test_init or test_help'"
+
@@ -10,7 +10,9 @@ jobs:
  deb:
    runs-on: ubuntu-18.04
    steps:
-    - uses: actions/[email protected].4
+    - uses: actions/[email protected].5
+      with:
+          fetch-depth: 0
    - name: Set up Python 3.8
      uses: actions/[email protected]
      with:
@@ -39,7 +41,9 @@ jobs:
  rpm:
    runs-on: ubuntu-18.04
    steps:
-    - uses: actions/[email protected].4
+    - uses: actions/[email protected].5
+      with:
+        fetch-depth: 0
    - name: Set up Python 3.8
      uses: actions/[email protected]
      with:
@@ -68,7 +72,9 @@ jobs:
  osxpkg:
    runs-on: macos-10.15
    steps:
-    - uses: actions/[email protected].4
+    - uses: actions/[email protected].5
+      with:
+        fetch-depth: 0
    - name: Set up Python 3.8
      uses: actions/[email protected]
      with:
@@ -100,7 +106,9 @@ jobs:
  exe:
    runs-on: windows-2019
    steps:
-    - uses: actions/[email protected].4
+    - uses: actions/[email protected].5
+      with:
+        fetch-depth: 0
    - name: Set up Python 3.8
      uses: actions/[email protected]
      with:
@@ -128,7 +136,9 @@ jobs:
  pip:
    runs-on: ubuntu-18.04
    steps:
-    - uses: actions/[email protected].4
+    - uses: actions/[email protected].5
+      with:
+        fetch-depth: 0
    - name: Set up Python 3.7
      uses: actions/[email protected]
      with:
@@ -136,7 +146,9 @@ jobs:
    - name: Install
      run: pip install ".[all,tests]"
    - name: Build packages
-      run: ./scripts/build_package.sh
+      run: |
+        pip install -U pip
+        ./scripts/build_package.sh
    - name: Publish packages to PyPI
      if: github.event_name == 'release'
      uses: pypa/gh-action-pypi-publish@master
@@ -16,7 +16,13 @@ jobs:
    timeout-minutes: 10
    runs-on: ubuntu-latest
    steps:
-    - uses: actions/[email protected]
+    - name: Cancel Previous Runs
+      uses: styfle/[email protected]
+      with:
+        access_token: ${{ github.token }}
+    - uses: actions/[email protected]
+      with:
+        fetch-depth: 0
    - name: Set up Python 3.8
      uses: actions/[email protected]
      with:
@@ -24,7 +30,7 @@ jobs:
    - name: Install requirements
      run: |
        pip install wheel
-        pip install ".[all,tests,terraform]" Pygments collective.checkdocs pre-commit
+        pip install ".[all,tests,terraform]" pre-commit
    - name: install temporary dependencies
      run: |
        pip install git+https://github.com/isidentical/gdrivefs@service-account
@@ -38,19 +44,16 @@ jobs:
    strategy:
      fail-fast: false
      matrix:
-        os: [ubuntu-18.04, windows-2019, macos-10.15]
-        pyv: ["3.6", "3.7", "3.8", "3.9"]
-        include:
-          - os: "macos-10.15"
-            pyv: "3.10.0-rc.1"
+        os: [ubuntu-20.04, windows-latest, macos-latest]
+        pyv: ["3.7", "3.8", "3.9", "3.10"]
        exclude:
-          - os: macos-10.15
-            pyv: "3.9"
-          - os: macos-10.15
-            pyv: "3.7"
-
+          # no wheels for pygit2 yet
+          - os: windows-latest
+            pyv: "3.10"
    steps:
-    - uses: actions/[email protected].4
+    - uses: actions/[email protected].5
+      with:
+        fetch-depth: 0
    - name: Set up Python
      uses: actions/[email protected]
      with:
@@ -64,13 +67,9 @@ jobs:
      uses: actions/[email protected]
      with:
        path: ${{ steps.pip-cache-dir.outputs.dir }}
-        key: ${{ runner.os }}-pip-${{ hashFiles('setup.py') }}
+        key: ${{ runner.os }}-pip-${{ hashFiles('setup.cfg') }}
        restore-keys: |
          ${{ runner.os }}-pip-
-    - name: install libgit2 on Python3.10 in macOS
-      if: matrix.pyv == '3.10.0-rc.1' && matrix.os == 'macos-10.15'
-      run: |
-        brew install libgit2
    - name: install
      if: steps.cache.pip-cache-dir.cache-hit != 'true'
      run: |
@@ -99,7 +98,7 @@ jobs:
      run: |
        echo "extra_test_args=--disable-gdrive" >> $GITHUB_ENV
    - name: run tests
-      timeout-minutes: 30
+      timeout-minutes: 40
      env:
        GDRIVE_CREDENTIALS_DATA: ${{ secrets.GDRIVE_CREDENTIALS_DATA }}
        AWS_ACCESS_KEY_ID: ${{ secrets.AWS_ACCESS_KEY_ID }}
@@ -110,9 +109,9 @@ jobs:
      run: >-
        python -m tests -n=4
        --cov-report=xml --cov-report=term
-        --all ${{ env.extra_test_args }}
+        --enable-ssh ${{ env.extra_test_args }}
    - name: upload coverage report
-      uses: codecov/codecov-action@v2.0.3
+      uses: codecov/codecov-action@v2.1.0
      with:
        file: ./coverage.xml
        fail_ci_if_error: false
@@ -13,6 +13,7 @@ build/
 dist/

 *.egg-info/
+.eggs

 hooks/*.pyc

@@ -38,3 +39,4 @@ scripts/ci/gcp-creds.json
 .gcp-creds.json

 *~
+/dvc/_dvc_version.py
@@ -6,7 +6,12 @@ repos:
      - id: black
        language_version: python3
    repo: https://github.com/ambv/black
-    rev: 21.8b0
+    rev: 21.9b0
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v4.0.1
+    hooks:
+      - id: check-toml
+      - id: check-yaml
  - hooks:
      - id: codespell
        args: 
@@ -39,7 +44,7 @@ repos:
           - types-tabulate
           - types-toml
    repo: https://github.com/pre-commit/mirrors-mypy
-    rev: 'v0.910'
+    rev: 'v0.910-1'
  - repo: local
    hooks:
    - id: pylint
@@ -54,7 +59,7 @@ repos:
        id: beautysh
        language_version: python3
    repo: https://github.com/lovesegfault/beautysh
-    rev: v6.1.0
+    rev: v6.2.1
  - hooks:
      - args:
          - git-hook
@@ -1,615 +0,0 @@
-[MASTER]
-
-# A comma-separated list of package or module names from where C extensions may
-# be loaded. Extensions are loading into the active Python interpreter and may
-# run arbitrary code.
-extension-pkg-whitelist=pygit2
-
-# Add files or directories to the blacklist. They should be base names, not
-# paths.
-ignore=CVS
-
-# Add files or directories matching the regex patterns to the blacklist. The
-# regex matches against base names, not paths.
-ignore-patterns=
-
-# Python code to execute, usually for sys.path manipulation such as
-# pygtk.require().
-init-hook="import sys;
-           from pathlib import Path;
-           from pylint.config import find_pylintrc;
-
-           tests_folder = Path(find_pylintrc()).parent / 'tests'
-           sys.path.append(str(tests_folder));
-           "
-
-
-# Use multiple processes to speed up Pylint. Specifying 0 will auto-detect the
-# number of processors available to use.
-jobs=1
-
-# Control the amount of potential inferred values when inferring a single
-# object. This can help the performance when dealing with large functions or
-# complex, nested conditions.
-limit-inference-results=100
-
-# List of plugins (as comma separated values of python modules names) to load,
-# usually to register additional checkers.
-load-plugins=pylint_pytest,pylint_plugin_disable
-
-# Pickle collected data for later comparisons.
-persistent=yes
-
-# Specify a configuration file.
-#rcfile=
-
-# When enabled, pylint would attempt to guess common misconfiguration and emit
-# user-friendly hints instead of false-positive error messages.
-suggestion-mode=yes
-
-# Allow loading of arbitrary C extensions. Extensions are imported into the
-# active Python interpreter and may run arbitrary code.
-unsafe-load-any-extension=no
-
-
-[MESSAGES CONTROL]
-
-# Only show warnings with the listed confidence levels. Leave empty to show
-# all. Valid levels: HIGH, INFERENCE, INFERENCE_FAILURE, UNDEFINED.
-confidence=
-
-# Disable the message, report, category or checker with the given id(s). You
-# can either give multiple identifiers separated by comma (,) or put this
-# option multiple times (only on the command line, not in the configuration
-# file where it should appear only once). You can also use "--disable=all" to
-# disable everything first and then reenable specific checks. For example, if
-# you want to run only the similarities checker, you can use "--disable=all
-# --enable=similarities". If you want to run only the classes checker, but have
-# no Warning level messages displayed, use "--disable=all --enable=classes
-# --disable=W".
-disable=format,
-        # ^ most of them are covered by flake8,
-        # and are conventions rather than warnings or errors
-        refactoring,  # will be noisy if it starts giving suggestions
-        spelling,
-        # design is too-few-* and too-many-* checks, too-much-* for us right now
-        design,
-        # following were generated by default
-        # most of them are redundant Py3 checks for Py2+3 codebase
-        print-statement,
-        parameter-unpacking,
-        unpacking-in-except,
-        old-raise-syntax,
-        backtick,
-        long-suffix,
-        old-ne-operator,
-        old-octal-literal,
-        import-star-module-level,
-        non-ascii-bytes-literal,
-        raw-checker-failed,
-        bad-inline-option,
-        locally-disabled,
-        file-ignored,
-        suppressed-message,
-        useless-suppression,
-        deprecated-pragma,
-        use-symbolic-message-instead,
-        apply-builtin,
-        basestring-builtin,
-        buffer-builtin,
-        cmp-builtin,
-        coerce-builtin,
-        execfile-builtin,
-        file-builtin,
-        long-builtin,
-        raw_input-builtin,
-        reduce-builtin,
-        standarderror-builtin,
-        unicode-builtin,
-        xrange-builtin,
-        coerce-method,
-        delslice-method,
-        getslice-method,
-        setslice-method,
-        no-absolute-import,
-        old-division,
-        dict-iter-method,
-        dict-view-method,
-        next-method-called,
-        metaclass-assignment,
-        indexing-exception,
-        raising-string,
-        reload-builtin,
-        oct-method,
-        hex-method,
-        nonzero-method,
-        cmp-method,
-        input-builtin,
-        round-builtin,
-        intern-builtin,
-        unichr-builtin,
-        map-builtin-not-iterating,
-        zip-builtin-not-iterating,
-        range-builtin-not-iterating,
-        filter-builtin-not-iterating,
-        using-cmp-argument,
-        eq-without-hash,
-        div-method,
-        idiv-method,
-        rdiv-method,
-        exception-message-attribute,
-        invalid-str-codec,
-        sys-max-int,
-        bad-python3-import,
-        deprecated-string-function,
-        deprecated-str-translate-call,
-        deprecated-itertools-function,
-        deprecated-types-field,
-        next-method-defined,
-        dict-items-not-iterating,
-        dict-keys-not-iterating,
-        dict-values-not-iterating,
-        deprecated-operator-function,
-        deprecated-urllib-function,
-        xreadlines-attribute,
-        deprecated-sys-function,
-        exception-escape,
-        comprehension-escape,
-        # custom disables start here
-        no-self-use,
-        invalid-name,
-        # already a check enabled for `wildcard-import`
-        unused-wildcard-import,
-        misplaced-comparison-constant,
-        # probably soon: https://github.com/iterative/dvc/issues/1843
-        logging-format-interpolation,
-        logging-fstring-interpolation,
-        # we don't have proper docstrings yet
-        # even if we do, we'll be doing it gradually
-        missing-function-docstring,
-        missing-module-docstring,
-        missing-class-docstring,
-        duplicate-code,
-        # too noisy, and detects issues even when import is inside a function
-        # see: https://github.com/PyCQA/pylint/issues/850
-        cyclic-import,
-        # isort should cover these:
-        wrong-import-order,
-        wrong-import-position,
-        ungrouped-imports,
-        multiple-imports,
-        # we use it to speedup/optimize
-        import-outside-toplevel,
-        fixme,
-        # we use cause of the exception for error message output
-        # so some of the times we don't use `raise from` to not show the cause
-        # of the error
-        raise-missing-from,
-
-# Enable the message, report, category or checker with the given id(s). You can
-# either give multiple identifier separated by comma (,) or put this option
-# multiple time (only on the command line, not in the configuration file where
-# it should appear only once). See also the "--disable" option for examples.
-enable=c-extension-no-member,
-       no-else-return,
-
-
-[REPORTS]
-
-# Python expression which should return a note less than 10 (10 is the highest
-# note). You have access to the variables errors warning, statement which
-# respectively contain the number of errors / warnings messages and the total
-# number of statements analyzed. This is used by the global evaluation report
-# (RP0004).
-evaluation=10.0 - ((float(5 * error + warning + refactor + convention) / statement) * 10)
-
-# Template used to display messages. This is a python new-style format string
-# used to format the message information. See doc for all details.
-#msg-template=
-
-# Set the output format. Available formats are text, parseable, colorized, json
-# and msvs (visual studio). You can also give a reporter class, e.g.
-# mypackage.mymodule.MyReporterClass.
-output-format=text
-
-# Tells whether to display a full report or only the messages.
-reports=no
-
-# Activate the evaluation score.
-score=yes
-
-
-[REFACTORING]
-
-# Maximum number of nested blocks for function / method body
-max-nested-blocks=5
-
-# Complete name of functions that never returns. When checking for
-# inconsistent-return-statements if a never returning function is called then
-# it will be considered as an explicit return statement and no message will be
-# printed.
-never-returning-functions=sys.exit
-
-
-[LOGGING]
-
-# Format style used to check logging format string. `old` means using %
-# formatting, while `new` is for `{}` formatting.
-logging-format-style=old
-
-# Logging modules to check that the string format arguments are in logging
-# function parameter format.
-logging-modules=logging
-
-
-[SPELLING]
-
-# Limits count of emitted suggestions for spelling mistakes.
-max-spelling-suggestions=4
-
-# Spelling dictionary name. Available dictionaries: none. To make it working
-# install python-enchant package..
-spelling-dict=
-
-# List of comma separated words that should not be checked.
-spelling-ignore-words=
-
-# A path to a file that contains private dictionary; one word per line.
-spelling-private-dict-file=
-
-# Tells whether to store unknown words to indicated private dictionary in
-# --spelling-private-dict-file option instead of raising a message.
-spelling-store-unknown-words=no
-
-
-[TYPECHECK]
-
-# List of decorators that produce context managers, such as
-# contextlib.contextmanager. Add to this list to register other decorators that
-# produce valid context managers.
-contextmanager-decorators=contextlib.contextmanager
-
-# List of members which are set dynamically and missed by pylint inference
-# system, and so shouldn't trigger E1101 when accessed. Python regular
-# expressions are accepted.
-generated-members=hdfs.*,pytest.lazy_fixture,logging.TRACE,logger.trace,sys.getwindowsversion
-
-# Tells whether missing members accessed in mixin class should be ignored. A
-# mixin class is detected if its name ends with "mixin" (case insensitive).
-ignore-mixin-members=yes
-
-# Tells whether to warn about missing members when the owner of the attribute
-# is inferred to be None.
-ignore-none=yes
-
-# This flag controls whether pylint should warn about no-member and similar
-# checks whenever an opaque object is returned when inferring. The inference
-# can return multiple potential results while evaluating a Python object, but
-# some branches might not be evaluated, which results in partial inference. In
-# that case, it might be useful to still emit no-member and other checks for
-# the rest of the inferred objects.
-ignore-on-opaque-inference=yes
-
-# List of class names for which member attributes should not be checked (useful
-# for classes with dynamically set attributes). This supports the use of
-# qualified names.
-ignored-classes=optparse.Values,thread._local,_thread._local,Dvcfile
-
-# List of module names for which member attributes should not be checked
-# (useful for modules/projects where namespaces are manipulated during runtime
-# and thus existing member attributes cannot be deduced by static analysis. It
-# supports qualified module names, as well as Unix pattern matching.
-ignored-modules=azure
-
-# Show a hint with possible names when a member name was not found. The aspect
-# of finding the hint is based on edit distance.
-missing-member-hint=yes
-
-# The minimum edit distance a name should have in order to be considered a
-# similar match for a missing member name.
-missing-member-hint-distance=1
-
-# The total number of similar names that should be taken in consideration when
-# showing a hint for a missing member.
-missing-member-max-choices=1
-
-signature-mutators=funcy.decorators.decorator,
-
-[VARIABLES]
-
-# List of additional names supposed to be defined in builtins. Remember that
-# you should avoid defining new builtins when possible.
-additional-builtins=
-
-# Tells whether unused global variables should be treated as a violation.
-allow-global-unused-variables=yes
-
-# List of strings which can identify a callback function by name. A callback
-# name must start or end with one of those strings.
-callbacks=cb_,
-          _cb
-
-# A regular expression matching the name of dummy variables (i.e. expected to
-# not be used).
-dummy-variables-rgx=_+$|(_[a-zA-Z0-9_]*[a-zA-Z0-9]+?$)|dummy|^ignored_|^unused_
-
-# Argument names that match this expression will be ignored. Default to name
-# with leading underscore.
-ignored-argument-names=_.*|^ignored_|^unused_|args|kwargs
-
-# Tells whether we should check for unused import in __init__ files.
-init-import=no
-
-# List of qualified module names which can have objects that can redefine
-# builtins.
-redefining-builtins-modules=six.moves,past.builtins,future.builtins,builtins,io
-
-
-[FORMAT]
-
-# Expected format of line ending, e.g. empty (any line ending), LF or CRLF.
-expected-line-ending-format=
-
-# Regexp for a line that is allowed to be longer than the limit.
-ignore-long-lines=^\s*(# )?<?https?://\S+>?$
-
-# Number of spaces of indent required inside a hanging or continued line.
-indent-after-paren=4
-
-# String used as indentation unit. This is usually "    " (4 spaces) or "\t" (1
-# tab).
-indent-string='    '
-
-# Maximum number of characters on a single line.
-max-line-length=79
-
-# Maximum number of lines in a module.
-max-module-lines=1000
-
-# List of optional constructs for which whitespace checking is disabled. `dict-
-# separator` is used to allow tabulation in dicts, etc.: {1  : 1,\n222: 2}.
-# `trailing-comma` allows a space between comma and closing bracket: (a, ).
-# `empty-line` allows space-only lines.
-no-space-check=trailing-comma,
-               dict-separator
-
-# Allow the body of a class to be on the same line as the declaration if body
-# contains single statement.
-single-line-class-stmt=no
-
-# Allow the body of an if to be on the same line as the test if there is no
-# else.
-single-line-if-stmt=no
-
-
-[BASIC]
-
-# Naming style matching correct argument names.
-argument-naming-style=snake_case
-
-# Regular expression matching correct argument names. Overrides argument-
-# naming-style.
-#argument-rgx=
-
-# Naming style matching correct attribute names.
-attr-naming-style=snake_case
-
-# Regular expression matching correct attribute names. Overrides attr-naming-
-# style.
-#attr-rgx=
-
-# Bad variable names which should always be refused, separated by a comma.
-bad-names=foo,
-          bar,
-          baz,
-          toto,
-          tutu,
-          tata
-
-# Naming style matching correct class attribute names.
-class-attribute-naming-style=any
-
-# Regular expression matching correct class attribute names. Overrides class-
-# attribute-naming-style.
-#class-attribute-rgx=
-
-# Naming style matching correct class names.
-class-naming-style=PascalCase
-
-# Regular expression matching correct class names. Overrides class-naming-
-# style.
-#class-rgx=
-
-# Naming style matching correct constant names.
-const-naming-style=UPPER_CASE
-
-# Regular expression matching correct constant names. Overrides const-naming-
-# style.
-#const-rgx=
-
-# Minimum line length for functions/classes that require docstrings, shorter
-# ones are exempt.
-docstring-min-length=-1
-
-# Naming style matching correct function names.
-function-naming-style=snake_case
-
-# Regular expression matching correct function names. Overrides function-
-# naming-style.
-#function-rgx=
-
-# Good variable names which should always be accepted, separated by a comma.
-good-names=i,
-           j,
-           k,
-           ex,
-           Run,
-           _,
-           s3,
-           gs,
-           x, y,
-           x0, y0,
-           x1, y1,
-           dx, dy
-
-# Include a hint for the correct naming format with invalid-name.
-include-naming-hint=no
-
-# Naming style matching correct inline iteration names.
-inlinevar-naming-style=any
-
-# Regular expression matching correct inline iteration names. Overrides
-# inlinevar-naming-style.
-#inlinevar-rgx=
-
-# Naming style matching correct method names.
-method-naming-style=snake_case
-
-# Regular expression matching correct method names. Overrides method-naming-
-# style.
-#method-rgx=
-
-# Naming style matching correct module names.
-module-naming-style=snake_case
-
-# Regular expression matching correct module names. Overrides module-naming-
-# style.
-#module-rgx=
-
-# Colon-delimited sets of names that determine each other's naming style when
-# the name regexes allow several styles.
-name-group=
-
-# Regular expression which should only match function or class names that do
-# not require a docstring.
-no-docstring-rgx=^_
-
-# List of decorators that produce properties, such as abc.abstractproperty. Add
-# to this list to register other decorators that produce valid properties.
-# These decorators are taken in consideration only for invalid-name.
-property-classes=abc.abstractproperty
-
-# Naming style matching correct variable names.
-variable-naming-style=snake_case
-
-# Regular expression matching correct variable names. Overrides variable-
-# naming-style.
-#variable-rgx=
-
-
-[SIMILARITIES]
-
-# Ignore comments when computing similarities.
-ignore-comments=yes
-
-# Ignore docstrings when computing similarities.
-ignore-docstrings=yes
-
-# Ignore imports when computing similarities.
-ignore-imports=no
-
-# Minimum lines number of a similarity.
-min-similarity-lines=4
-
-
-[MISCELLANEOUS]
-
-# List of note tags to take in consideration, separated by a comma.
-notes=FIXME,
-      XXX,
-      TODO
-
-
-[DESIGN]
-
-# Maximum number of arguments for function / method.
-max-args=5
-
-# Maximum number of attributes for a class (see R0902).
-max-attributes=7
-
-# Maximum number of boolean expressions in an if statement.
-max-bool-expr=5
-
-# Maximum number of branch for function / method body.
-max-branches=12
-
-# Maximum number of locals for function / method body.
-max-locals=15
-
-# Maximum number of parents for a class (see R0901).
-max-parents=7
-
-# Maximum number of public methods for a class (see R0904).
-max-public-methods=20
-
-# Maximum number of return / yield for function / method body.
-max-returns=6
-
-# Maximum number of statements in function / method body.
-max-statements=50
-
-# Minimum number of public methods for a class (see R0903).
-min-public-methods=2
-
-
-[CLASSES]
-
-# List of method names used to declare (i.e. assign) instance attributes.
-defining-attr-methods=__init__,
-                      __new__,
-                      setUp
-
-# List of member names, which should be excluded from the protected access
-# warning.
-exclude-protected=_asdict,
-                  _fields,
-                  _replace,
-                  _source,
-                  _make
-
-# List of valid names for the first argument in a class method.
-valid-classmethod-first-arg=cls
-
-# List of valid names for the first argument in a metaclass class method.
-valid-metaclass-classmethod-first-arg=cls
-
-
-[IMPORTS]
-
-# Allow wildcard imports from modules that define __all__.
-allow-wildcard-with-all=no
-
-# Analyse import fallback blocks. This can be used to support both Python 2 and
-# 3 compatible code, which means that the block might have code that exists
-# only in one or another interpreter, leading to false positives when analysed.
-analyse-fallback-blocks=no
-
-# Deprecated modules which should not be used, separated by a comma.
-deprecated-modules=optparse,tkinter.tix
-
-# Create a graph of external dependencies in the given file (report RP0402 must
-# not be disabled).
-ext-import-graph=
-
-# Create a graph of every (i.e. internal and external) dependencies in the
-# given file (report RP0402 must not be disabled).
-import-graph=
-
-# Create a graph of internal dependencies in the given file (report RP0402 must
-# not be disabled).
-int-import-graph=
-
-# Force import order to recognize a module as part of the standard
-# compatibility libraries.
-known-standard-library=
-
-# Force import order to recognize a module as part of a third party library.
-known-third-party=enchant
-
-
-[EXCEPTIONS]
-
-# Exceptions that will emit a warning when being caught. Defaults to
-# "Exception".
-overgeneral-exceptions=Exception
@@ -186,7 +186,7 @@
      same "printed page" as the copyright notice for easier
      identification within third-party archives.

-   Copyright {yyyy} {name of copyright owner}
+   Copyright 2017-2021 Iterative, Inc.

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
@@ -1,3 +1,3 @@
-include fastentrypoints.py
 include LICENSE
 recursive-include requirements *.txt
+recursive-include dvc/repo/plots/templates *.json
@@ -1,10 +1,39 @@
 from contextlib import ExitStack, contextmanager
-from typing import TYPE_CHECKING
+from typing import TYPE_CHECKING, Callable, Union

 if TYPE_CHECKING:
    from argparse import Namespace


+@contextmanager
+def yappi_profile(
+    path: Union[Callable[[], str], str] = None, wall_clock: bool = True
+):
+    try:
+        import yappi  # pylint: disable=import-error
+    except ImportError:
+        print("Failed to run profiler, yappi is not installed")
+        yield
+        return
+
+    yappi.set_clock_type("wall" if wall_clock else "cpu")
+
+    yappi.start()
+    yield
+    yappi.stop()
+
+    # pylint:disable=no-member
+    if path:
+        stats = yappi.get_func_stats()
+        fpath = path() if callable(path) else path
+        stats.save(fpath, "callgrind")
+    else:
+        yappi.get_func_stats().print_all()
+        yappi.get_thread_stats().print_all()
+
+    yappi.clear_stats()
+
+
@contextmanager
 def instrument(html_output=False):
    """Run a statistical profiler"""
@@ -70,6 +99,13 @@ def debugtools(args: "Namespace" = None, **kwargs):
            stack.enter_context(profile(kw.get("cprofile_dump")))
        if kw.get("instrument") or kw.get("instrument_open"):
            stack.enter_context(instrument(kw.get("instrument_open", False)))
+        if kw.get("yappi"):
+            from datetime import datetime
+
+            output = "callgrind.dvc-{0:%Y%m%d}_{0:%H%M%S}.out"
+            stack.enter_context(
+                yappi_profile(path=lambda: output.format(datetime.now()))
+            )
        yield


@@ -79,6 +115,9 @@ def add_debugging_flags(parser):
    parser.add_argument(
        "--cprofile", action="store_true", default=False, help=SUPPRESS
    )
+    parser.add_argument(
+        "--yappi", action="store_true", default=False, help=SUPPRESS
+    )
    parser.add_argument("--cprofile-dump", help=SUPPRESS)
    parser.add_argument(
        "--pdb", action="store_true", default=False, help=SUPPRESS
@@ -68,7 +68,7 @@ def send(path):
    url = "https://analytics.dvc.org"
    headers = {"content-type": "application/json"}

-    with open(path) as fobj:
+    with open(path, encoding="utf-8") as fobj:
        report = json.load(fobj)

    report.update(_runtime_info())
@@ -173,13 +173,13 @@ def _find_or_create_user_id():
    try:
        with Lock(lockfile):
            try:
-                with open(fname) as fobj:
+                with open(fname, encoding="utf-8") as fobj:
                    user_id = json.load(fobj)["user_id"]

            except (FileNotFoundError, ValueError, KeyError):
                user_id = str(uuid.uuid4())

-                with open(fname, "w") as fobj:
+                with open(fname, "w", encoding="utf-8") as fobj:
                    json.dump({"user_id": user_id}, fobj)

            return user_id
@@ -113,7 +113,7 @@ def make_checkpoint():
        root_dir, Repo.DVC_DIR, "tmp", CheckpointTask.SIGNAL_FILE
    )

-    with builtins.open(signal_file, "w") as fobj:
+    with builtins.open(signal_file, "w", encoding="utf-8") as fobj:
        # NOTE: force flushing/writing empty file to disk, otherwise when
        # run in certain contexts (pytest) file may not actually be written
        fobj.write("")
@@ -66,7 +66,8 @@ class CmdConfig(CmdBaseNoRepo):
            )
            return 1

-        levels = [self.args.level] if self.args.level else self.config.LEVELS
+        levels = self._get_appropriate_levels(self.args.level)
+
        for level in levels:
            conf = self.config.read(level)
            prefix = self._config_file_prefix(
@@ -81,9 +82,7 @@ class CmdConfig(CmdBaseNoRepo):
    def _get(self, remote, section, opt):
        from dvc.config import ConfigError

-        levels = (
-            [self.args.level] if self.args.level else self.config.LEVELS[::-1]
-        )
+        levels = self._get_appropriate_levels(self.args.level)[::-1]

        for level in levels:
            conf = self.config.read(level)
@@ -136,6 +135,20 @@ class CmdConfig(CmdBaseNoRepo):
                f"option '{opt}' doesn't exist in {name} '{section}'"
            )

+    def _get_appropriate_levels(self, levels):
+        if levels:
+            self._validate_level_for_non_repo_operation(levels)
+            return [levels]
+        if self.config.dvc_dir is None:
+            return self.config.SYSTEM_LEVELS
+        return self.config.LEVELS
+
+    def _validate_level_for_non_repo_operation(self, level):
+        from dvc.config import ConfigError
+
+        if self.config.dvc_dir is None and level in self.config.REPO_LEVELS:
+            raise ConfigError("Not inside a DVC repo")
+
    @staticmethod
    def _format_config(config, prefix=""):
        from dvc.utils.flatten import flatten
@@ -103,9 +103,8 @@ class CmdDAG(CmdBase):
        if self.args.dot:
            ui.write(_show_dot(G))
        else:
-            from dvc.utils.pager import pager
-
-            pager(_show_ascii(G))
+            with ui.pager():
+                ui.write(_show_ascii(G))

        return 0

@@ -393,6 +393,7 @@ def add_parser(subparsers, _parent_parser):
        help="Show status of all stages in the specified directory.",
    )
    status_parser.add_argument(
+        "--json",
        "--show-json",
        action="store_true",
        default=False,
@@ -1,5 +1,4 @@
 import argparse
-import json
 import logging
 import os

@@ -16,7 +15,7 @@ def _digest(checksum):
    return "{}..{}".format(checksum["old"][0:8], checksum["new"][0:8])


-def _show_md(diff, show_hash=False, hide_missing=False):
+def _show_markdown(diff, show_hash=False, hide_missing=False):
    headers = ["Status", "Hash", "Path"] if show_hash else ["Status", "Path"]
    rows = []
    statuses = ["added", "deleted", "renamed", "modified"]
@@ -142,10 +141,10 @@ class CmdDiff(CmdBase):
                        del entry["hash"]
                diff[key] = entries

-            if self.args.show_json:
-                ui.write(json.dumps(diff))
-            elif self.args.show_md:
-                _show_md(diff, show_hash, hide_missing)
+            if self.args.json:
+                ui.write_json(diff)
+            elif self.args.markdown:
+                _show_markdown(diff, show_hash, hide_missing)
            elif diff:
                self._show_diff(diff, hide_missing)

@@ -188,6 +187,7 @@ def add_parser(subparsers, parent_parser):
        nargs="?",
    )
    diff_parser.add_argument(
+        "--json",
        "--show-json",
        help="Format the output into a JSON",
        action="store_true",
@@ -200,9 +200,11 @@ def add_parser(subparsers, parent_parser):
        default=False,
    )
    diff_parser.add_argument(
+        "--md",
        "--show-md",
        help="Show tabulated output in the Markdown format (GFM).",
        action="store_true",
+        dest="markdown",
        default=False,
    )
    diff_parser.add_argument(
@@ -5,9 +5,8 @@ from datetime import date, datetime
 from fnmatch import fnmatch
 from typing import TYPE_CHECKING, Dict, Iterable, Optional

-from funcy import lmap
+from funcy import compact, lmap

-from dvc import prompt
 from dvc.command import completion
 from dvc.command.base import CmdBase, append_doc_link, fix_subparsers
 from dvc.command.metrics import DEFAULT_PRECISION
@@ -19,9 +18,8 @@ from dvc.utils.flatten import flatten
 from dvc.utils.serialize import encode_exception

 if TYPE_CHECKING:
-    from rich.text import Text
-
    from dvc.compare import TabularData
+    from dvc.ui import RichText


 logger = logging.getLogger(__name__)
@@ -260,11 +258,12 @@ def _sort_column(sort_by, metric_names, param_names):
 def _sort_exp(experiments, sort_path, sort_name, typ, reverse):
    def _sort(item):
        rev, exp = item
-        tip = exp.get("checkpoint_tip")
+        exp_data = exp.get("data", {})
+        tip = exp_data.get("checkpoint_tip")
        if tip and tip != rev:
            # Sort checkpoint experiments by tip commit
            return _sort((tip, experiments[tip]))
-        data = exp.get(typ, {}).get(sort_path, {})
+        data = exp_data.get(typ, {}).get(sort_path, {}).get("data", {})
        val = flatten(data).get(sort_name)
        return val is None, val

@@ -291,8 +290,6 @@ def _format_time(datetime_obj, fill_value=FILL_VALUE, iso=False):


 def _extend_row(row, names, items, precision, fill_value=FILL_VALUE):
-    from rich.text import Text
-
    from dvc.compare import _format_field, with_value

    if not items:
@@ -307,10 +304,10 @@ def _extend_row(row, names, items, precision, fill_value=FILL_VALUE):
                item.get(name),
                FILL_VALUE_ERRORED if data.get("error", None) else fill_value,
            )
-            # wrap field data in rich.Text, otherwise rich may
+            # wrap field data in ui.rich_text, otherwise rich may
            # interpret unescaped braces from list/dict types as rich
            # markup tags
-            row.append(Text(str(_format_field(value, precision))))
+            row.append(ui.rich_text(str(_format_field(value, precision))))


 def _parse_filter_list(param_list):
@@ -361,17 +358,15 @@ def experiments_table(
    return td


-def prepare_exp_id(kwargs) -> "Text":
-    from rich.text import Text
-
+def prepare_exp_id(kwargs) -> "RichText":
    exp_name = kwargs["Experiment"]
    rev = kwargs["rev"]
    typ = kwargs.get("typ", "baseline")

    if typ == "baseline" or not exp_name:
-        text = Text(exp_name or rev)
+        text = ui.rich_text(exp_name or rev)
    else:
-        text = Text.assemble(rev, " [", (exp_name, "bold"), "]")
+        text = ui.rich_text.assemble(rev, " [", (exp_name, "bold"), "]")

    parent = kwargs.get("parent")
    suff = f" ({parent})" if parent else ""
@@ -379,7 +374,7 @@ def prepare_exp_id(kwargs) -> "Text":

    tree = experiment_types[typ]
    pref = f"{tree} " if tree else ""
-    return Text(pref) + text
+    return ui.rich_text(pref) + text


 def baseline_styler(typ):
@@ -387,7 +382,12 @@ def baseline_styler(typ):


 def show_experiments(
-    all_experiments, pager=True, no_timestamp=False, show_csv=False, **kwargs
+    all_experiments,
+    pager=True,
+    no_timestamp=False,
+    csv=False,
+    markdown=False,
+    **kwargs,
 ):
    from funcy.seqs import flatten as flatten_list

@@ -443,7 +443,7 @@ def show_experiments(

    row_styles = lmap(baseline_styler, td.column("typ"))

-    if not show_csv:
+    if not csv:
        merge_headers = ["Experiment", "rev", "typ", "parent"]
        td.column("Experiment")[:] = map(
            prepare_exp_id, td.as_dict(merge_headers)
@@ -477,7 +477,8 @@ def show_experiments(
        rich_table=True,
        header_styles=styles,
        row_styles=row_styles,
-        show_csv=show_csv,
+        csv=csv,
+        markdown=markdown,
    )


@@ -510,18 +511,16 @@ class CmdExperimentsShow(CmdBase):
            logger.exception("failed to show experiments")
            return 1

-        if self.args.show_json:
-            import json
-
-            ui.write(json.dumps(all_experiments, default=_format_json))
+        if self.args.json:
+            ui.write_json(all_experiments, default=_format_json)
        else:
            precision = (
                self.args.precision or None
-                if self.args.show_csv
+                if self.args.csv
                else DEFAULT_PRECISION
            )
-            fill_value = "" if self.args.show_csv else FILL_VALUE
-            iso = True if self.args.show_csv else False
+            fill_value = "" if self.args.csv else FILL_VALUE
+            iso = True if self.args.csv else False

            show_experiments(
                all_experiments,
@@ -536,7 +535,8 @@ class CmdExperimentsShow(CmdBase):
                fill_value=fill_value,
                iso=iso,
                pager=not self.args.no_pager,
-                show_csv=self.args.show_csv,
+                csv=self.args.csv,
+                markdown=self.args.markdown,
            )
        return 0

@@ -565,10 +565,8 @@ class CmdExperimentsDiff(CmdBase):
            logger.exception("failed to show experiments diff")
            return 1

-        if self.args.show_json:
-            import json
-
-            ui.write(json.dumps(diff))
+        if self.args.json:
+            ui.write_json(diff)
        else:
            from dvc.compare import show_diff

@@ -583,11 +581,13 @@ class CmdExperimentsDiff(CmdBase):
                show_diff(
                    diff[key],
                    title=title,
-                    markdown=self.args.show_md,
+                    markdown=self.args.markdown,
                    no_path=self.args.no_path,
                    old=self.args.old,
                    on_empty_diff="diff not supported",
                    precision=precision if key == "metrics" else None,
+                    a_rev=self.args.a_rev,
+                    b_rev=self.args.b_rev,
                )

        return 0
@@ -668,7 +668,7 @@ class CmdExperimentsGC(CmdRepro):
        logger.warning(msg)

        msg = "Are you sure you want to proceed?"
-        if not self.args.force and not prompt.confirm(msg):
+        if not self.args.force and not ui.confirm(msg):
            return 1

        removed = self.repo.experiments.gc(
@@ -789,6 +789,77 @@ class CmdExperimentsRemove(CmdBase):
        return 0


+class CmdExperimentsInit(CmdBase):
+    CODE = "src"
+    DATA = "data"
+    MODELS = "models"
+    DEFAULT_METRICS = "metrics.json"
+    DEFAULT_PARAMS = "params.yaml"
+    PLOTS = "plots"
+    DVCLIVE = "dvclive"
+    DEFAULTS = {
+        "code": CODE,
+        "data": DATA,
+        "models": MODELS,
+        "metrics": DEFAULT_METRICS,
+        "params": DEFAULT_PARAMS,
+        "plots": PLOTS,
+        "live": DVCLIVE,
+    }
+
+    def run(self):
+        from dvc.command.stage import parse_cmd
+
+        cmd = parse_cmd(self.args.cmd)
+        if not self.args.interactive and not cmd:
+            raise InvalidArgumentError("command is not specified")
+
+        from dvc.repo.experiments.init import init
+
+        defaults = {}
+        if not self.args.explicit:
+            config = self.repo.config["exp"]
+            defaults.update({**self.DEFAULTS, **config})
+
+        cli_args = compact(
+            {
+                "cmd": cmd,
+                "code": self.args.code,
+                "data": self.args.data,
+                "models": self.args.models,
+                "metrics": self.args.metrics,
+                "params": self.args.params,
+                "plots": self.args.plots,
+                "live": self.args.live,
+            }
+        )
+
+        initialized_stage = init(
+            self.repo,
+            name=self.args.name,
+            type=self.args.type,
+            defaults=defaults,
+            overrides=cli_args,
+            interactive=self.args.interactive,
+            force=self.args.force,
+        )
+        if self.args.run:
+            return self.repo.experiments.run(
+                targets=[initialized_stage.addressing]
+            )
+        return 0
+
+
+class RawDefaultsHelpFormatter(
+    argparse.RawDescriptionHelpFormatter,
+    argparse.ArgumentDefaultsHelpFormatter,
+):
+    def _get_help_string(self, action: argparse.Action) -> Optional[str]:
+        if action.default:
+            return super()._get_help_string(action)
+        return action.help
+
+
 def add_parser(subparsers, parent_parser):
    EXPERIMENTS_HELP = "Commands to run and compare experiments."

@@ -894,7 +965,10 @@ def add_parser(subparsers, parent_parser):
    )
    experiments_show_parser.add_argument(
        "--sort-order",
-        help="Sort order to use with --sort-by.",
+        help=(
+            "Sort order to use with --sort-by."
+            " Defaults to ascending ('asc')."
+        ),
        choices=("asc", "desc"),
        default="asc",
    )
@@ -911,17 +985,27 @@ def add_parser(subparsers, parent_parser):
        help="Always show git commit SHAs instead of branch/tag names.",
    )
    experiments_show_parser.add_argument(
+        "--json",
        "--show-json",
        action="store_true",
        default=False,
        help="Print output in JSON format instead of a human-readable table.",
    )
    experiments_show_parser.add_argument(
+        "--csv",
        "--show-csv",
        action="store_true",
        default=False,
        help="Print output in csv format instead of a human-readable table.",
    )
+    experiments_show_parser.add_argument(
+        "--md",
+        "--show-md",
+        action="store_true",
+        default=False,
+        dest="markdown",
+        help="Show tabulated output in the Markdown format (GFM).",
+    )
    experiments_show_parser.add_argument(
        "--precision",
        type=int,
@@ -985,22 +1069,25 @@ def add_parser(subparsers, parent_parser):
        help="Show only params that are stage dependencies.",
    )
    experiments_diff_parser.add_argument(
+        "--json",
        "--show-json",
        action="store_true",
        default=False,
        help="Show output in JSON format.",
    )
    experiments_diff_parser.add_argument(
+        "--md",
        "--show-md",
        action="store_true",
        default=False,
+        dest="markdown",
        help="Show tabulated output in the Markdown format (GFM).",
    )
    experiments_diff_parser.add_argument(
        "--old",
        action="store_true",
        default=False,
-        help="Show old metric/param value.",
+        help="Show old ('a_rev') metric/param value.",
    )
    experiments_diff_parser.add_argument(
        "--no-path",
@@ -1303,6 +1390,92 @@ def add_parser(subparsers, parent_parser):
    )
    experiments_remove_parser.set_defaults(func=CmdExperimentsRemove)

+    EXPERIMENTS_INIT_HELP = "Initialize experiments."
+    experiments_init_parser = experiments_subparsers.add_parser(
+        "init",
+        parents=[parent_parser],
+        description=append_doc_link(EXPERIMENTS_INIT_HELP, "exp/init"),
+        formatter_class=RawDefaultsHelpFormatter,
+    )
+    experiments_init_parser.add_argument(
+        "cmd",
+        nargs=argparse.REMAINDER,
+        help="Command to execute.",
+        metavar="command",
+    )
+    experiments_init_parser.add_argument(
+        "--run",
+        action="store_true",
+        help="Run the experiment after initializing it",
+    )
+    experiments_init_parser.add_argument(
+        "--interactive",
+        "-i",
+        action="store_true",
+        help="Prompt for values that are not provided",
+    )
+    experiments_init_parser.add_argument(
+        "-f",
+        "--force",
+        action="store_true",
+        default=False,
+        help="Overwrite existing stage",
+    )
+
+    experiments_init_parser.add_argument(
+        "--explicit",
+        action="store_true",
+        default=False,
+        help="Only use the path values explicitly provided",
+    )
+    experiments_init_parser.add_argument(
+        "--name", "-n", help="Name of the stage to create"
+    )
+    experiments_init_parser.add_argument(
+        "--code",
+        default=CmdExperimentsInit.CODE,
+        help="Path to the source file or directory "
+        "which your experiments depend",
+    )
+    experiments_init_parser.add_argument(
+        "--data",
+        default=CmdExperimentsInit.DATA,
+        help="Path to the data file or directory "
+        "which your experiments depend",
+    )
+    experiments_init_parser.add_argument(
+        "--models",
+        default=CmdExperimentsInit.MODELS,
+        help="Path to the model file or directory for your experiments",
+    )
+    experiments_init_parser.add_argument(
+        "--params",
+        default=CmdExperimentsInit.DEFAULT_PARAMS,
+        help="Path to the parameters file for your experiments",
+    )
+    experiments_init_parser.add_argument(
+        "--metrics",
+        default=CmdExperimentsInit.DEFAULT_METRICS,
+        help="Path to the metrics file for your experiments",
+    )
+    experiments_init_parser.add_argument(
+        "--plots",
+        default=CmdExperimentsInit.PLOTS,
+        help="Path to the plots file or directory for your experiments",
+    )
+    experiments_init_parser.add_argument(
+        "--live",
+        help="Path to log dvclive outputs for your experiments "
+        f"(default: {CmdExperimentsInit.DVCLIVE})",
+    )
+    experiments_init_parser.add_argument(
+        "--type",
+        choices=["default", "live"],
+        default="default",
+        help="Select type of stage to create",
+    )
+    experiments_init_parser.set_defaults(func=CmdExperimentsInit)
+

 def _add_run_common(parser):
    """Add common args for 'exp run' and 'exp resume'."""
@@ -34,10 +34,8 @@ class CmdList(CmdBaseNoRepo):
                recursive=self.args.recursive,
                dvc_only=self.args.dvc_only,
            )
-            if self.args.show_json:
-                import json
-
-                ui.write(json.dumps(entries))
+            if self.args.json:
+                ui.write_json(entries)
            elif entries:
                entries = _prettify(entries, with_color=True)
                ui.write("\n".join(entries))
@@ -54,6 +52,7 @@ def add_parser(subparsers, parent_parser):
    )
    list_parser = subparsers.add_parser(
        "list",
+        aliases=["ls"],
        parents=[parent_parser],
        description=append_doc_link(LIST_HELP, "list"),
        help=LIST_HELP,
@@ -70,7 +69,10 @@ def add_parser(subparsers, parent_parser):
        "--dvc-only", action="store_true", help="Show only DVC outputs."
    )
    list_parser.add_argument(
-        "--show-json", action="store_true", help="Show output in JSON format."
+        "--json",
+        "--show-json",
+        action="store_true",
+        help="Show output in JSON format.",
    )
    list_parser.add_argument(
        "--rev",
@@ -3,6 +3,7 @@ import argparse
 from dvc.command.base import CmdBase, append_doc_link, fix_subparsers
 from dvc.command.config import CmdConfig
 from dvc.config import ConfigError
+from dvc.exceptions import DvcException
 from dvc.ui import ui
 from dvc.utils import format_link

@@ -69,6 +70,22 @@ class CmdMachineRemove(CmdMachineConfig):
        return 0


+class CmdMachineList(CmdMachineConfig):
+    def run(self):
+        levels = [self.args.level] if self.args.level else self.config.LEVELS
+        for level in levels:
+            conf = self.config.read(level)["machine"]
+            if self.args.name:
+                conf = conf.get(self.args.name, {})
+            prefix = self._config_file_prefix(
+                self.args.show_origin, self.config, level
+            )
+            configs = list(self._format_config(conf, prefix))
+            if configs:
+                ui.write("\n".join(configs))
+        return 0
+
+
 class CmdMachineModify(CmdMachineConfig):
    def run(self):
        from dvc.config import merge
@@ -88,6 +105,54 @@ class CmdMachineModify(CmdMachineConfig):
        return 0


+class CmdMachineRename(CmdBase):
+    def _check_exists(self, conf):
+        if self.args.name not in conf["machine"]:
+            raise ConfigError(f"machine '{self.args.name}' doesn't exist.")
+
+    def _rename_default(self, conf):
+        if conf["core"].get("machine") == self.args.name:
+            conf["core"]["machine"] = self.args.new
+
+    def _check_before_rename(self):
+        from dvc.machine import validate_name
+
+        validate_name(self.args.new)
+
+        all_config = self.config.load_config_to_level(None)
+        if self.args.new in all_config.get("machine", {}):
+            raise ConfigError(
+                "Rename failed. Machine '{}' already exists.".format(
+                    self.args.new
+                )
+            )
+        ui.write(f"Rename machine '{self.args.name}' to '{self.args.new}'.")
+
+    def run(self):
+
+        self._check_before_rename()
+
+        with self.config.edit(self.args.level) as conf:
+            self._check_exists(conf)
+            conf["machine"][self.args.new] = conf["machine"][self.args.name]
+            try:
+                self.repo.machine.rename(self.args.name, self.args.new)
+            except DvcException as error:
+                del conf["machine"][self.args.new]
+                raise ConfigError("terraform rename failed") from error
+            del conf["machine"][self.args.name]
+            self._rename_default(conf)
+
+        up_to_level = self.args.level or "repo"
+        for level in reversed(self.config.LEVELS):
+            if level == up_to_level:
+                break
+            with self.config.edit(level) as level_conf:
+                self._rename_default(level_conf)
+
+        return 0
+
+
 class CmdMachineDefault(CmdMachineConfig):
    def run(self):
        if self.args.name is None and not self.args.unset:
@@ -127,6 +192,22 @@ class CmdMachineCreate(CmdBase):
        return 0


+class CmdMachineStatus(CmdBase):
+    SHOWN_FIELD = ["name", "cloud", "instance_hdd_size", "instance_ip"]
+
+    def run(self):
+        if self.repo.machine is None:
+            raise MachineDisabledError
+
+        all_status = self.repo.machine.status(self.args.name)
+        for i, status in enumerate(all_status, start=1):
+            ui.write(f"instance_num_{i}:")
+            for field in self.SHOWN_FIELD:
+                value = status.get(field, None)
+                ui.write(f"\t{field:20}: {value}")
+        return 0
+
+
 class CmdMachineDestroy(CmdBase):
    def run(self):
        if self.repo.machine is None:
@@ -219,6 +300,27 @@ def add_parser(subparsers, parent_parser):
    )
    machine_default_parser.set_defaults(func=CmdMachineDefault)

+    machine_LIST_HELP = "List the configuration of one/all machines."
+    machine_list_parser = machine_subparsers.add_parser(
+        "list",
+        parents=[parent_config_parser, parent_parser],
+        description=append_doc_link(machine_LIST_HELP, "machine/list"),
+        help=machine_LIST_HELP,
+        formatter_class=argparse.RawDescriptionHelpFormatter,
+    )
+    machine_list_parser.add_argument(
+        "--show-origin",
+        default=False,
+        action="store_true",
+        help="Show the source file containing each config value.",
+    )
+    machine_list_parser.add_argument(
+        "name",
+        nargs="?",
+        type=str,
+        help="name of machine to specify",
+    )
+    machine_list_parser.set_defaults(func=CmdMachineList)
    machine_MODIFY_HELP = "Modify the configuration of an machine."
    machine_modify_parser = machine_subparsers.add_parser(
        "modify",
@@ -243,6 +345,18 @@ def add_parser(subparsers, parent_parser):
    )
    machine_modify_parser.set_defaults(func=CmdMachineModify)

+    machine_RENAME_HELP = "Rename a machine "
+    machine_rename_parser = machine_subparsers.add_parser(
+        "rename",
+        parents=[parent_config_parser, parent_parser],
+        description=append_doc_link(machine_RENAME_HELP, "remote/rename"),
+        help=machine_RENAME_HELP,
+        formatter_class=argparse.RawDescriptionHelpFormatter,
+    )
+    machine_rename_parser.add_argument("name", help="Machine to be renamed")
+    machine_rename_parser.add_argument("new", help="New name of the machine")
+    machine_rename_parser.set_defaults(func=CmdMachineRename)
+
    machine_REMOVE_HELP = "Remove an machine."
    machine_remove_parser = machine_subparsers.add_parser(
        "remove",
@@ -269,6 +383,19 @@ def add_parser(subparsers, parent_parser):
    )
    machine_create_parser.set_defaults(func=CmdMachineCreate)

+    machine_STATUS_HELP = "List the status of a running machine."
+    machine_status_parser = machine_subparsers.add_parser(
+        "status",
+        parents=[parent_config_parser, parent_parser],
+        description=append_doc_link(machine_STATUS_HELP, "machine/status"),
+        help=machine_STATUS_HELP,
+        formatter_class=argparse.RawDescriptionHelpFormatter,
+    )
+    machine_status_parser.add_argument(
+        "name", help="Name of the running machine."
+    )
+    machine_status_parser.set_defaults(func=CmdMachineStatus)
+
    machine_DESTROY_HELP = "Destroy an machine instance."
    machine_destroy_parser = machine_subparsers.add_parser(
        "destroy",
@@ -31,16 +31,14 @@ class CmdMetricsShow(CmdMetricsBase):
            logger.exception("")
            return 1

-        if self.args.show_json:
-            import json
-
-            ui.write(json.dumps(metrics, default=encode_exception))
+        if self.args.json:
+            ui.write_json(metrics, default=encode_exception)
        else:
            from dvc.compare import show_metrics

            show_metrics(
                metrics,
-                markdown=self.args.show_md,
+                markdown=self.args.markdown,
                all_branches=self.args.all_branches,
                all_tags=self.args.all_tags,
                all_commits=self.args.all_commits,
@@ -65,20 +63,20 @@ class CmdMetricsDiff(CmdMetricsBase):
            logger.exception("failed to show metrics diff")
            return 1

-        if self.args.show_json:
-            import json
-
-            ui.write(json.dumps(diff))
+        if self.args.json:
+            ui.write_json(diff)
        else:
            from dvc.compare import show_diff

            show_diff(
                diff,
                title="Metric",
-                markdown=self.args.show_md,
+                markdown=self.args.markdown,
                no_path=self.args.no_path,
                precision=self.args.precision or DEFAULT_PRECISION,
                round_digits=True,
+                a_rev=self.args.a_rev,
+                b_rev=self.args.b_rev,
            )

        return 0
@@ -140,15 +138,18 @@ def add_parser(subparsers, parent_parser):
        help="Show metrics for all commits.",
    )
    metrics_show_parser.add_argument(
+        "--json",
        "--show-json",
        action="store_true",
        default=False,
        help="Show output in JSON format.",
    )
    metrics_show_parser.add_argument(
+        "--md",
        "--show-md",
        action="store_true",
        default=False,
+        dest="markdown",
        help="Show tabulated output in the Markdown format (GFM).",
    )
    metrics_show_parser.add_argument(
@@ -220,15 +221,18 @@ def add_parser(subparsers, parent_parser):
        help="Show unchanged metrics as well.",
    )
    metrics_diff_parser.add_argument(
+        "--json",
        "--show-json",
        action="store_true",
        default=False,
        help="Show output in JSON format.",
    )
    metrics_diff_parser.add_argument(
+        "--md",
        "--show-md",
        action="store_true",
        default=False,
+        dest="markdown",
        help="Show tabulated output in the Markdown format (GFM).",
    )
    metrics_diff_parser.add_argument(
@@ -25,19 +25,19 @@ class CmdParamsDiff(CmdBase):
            logger.exception("failed to show params diff")
            return 1

-        if self.args.show_json:
-            import json
-
-            ui.write(json.dumps(diff))
+        if self.args.json:
+            ui.write_json(diff)
        else:
            from dvc.compare import show_diff

            show_diff(
                diff,
                title="Param",
-                markdown=self.args.show_md,
+                markdown=self.args.markdown,
                no_path=self.args.no_path,
                show_changes=False,
+                a_rev=self.args.a_rev,
+                b_rev=self.args.b_rev,
            )

        return 0
@@ -103,15 +103,18 @@ def add_parser(subparsers, parent_parser):
        help="Show only params that are stage dependencies.",
    )
    params_diff_parser.add_argument(
+        "--json",
        "--show-json",
        action="store_true",
        default=False,
        help="Show output in JSON format.",
    )
    params_diff_parser.add_argument(
+        "--md",
        "--show-md",
        action="store_true",
        default=False,
+        dest="markdown",
        help="Show tabulated output in the Markdown format (GFM).",
    )
    params_diff_parser.add_argument(
@@ -183,7 +183,10 @@ def add_parser(subparsers, parent_parser):
    _add_output_arguments(plots_diff_parser)
    plots_diff_parser.set_defaults(func=CmdPlotsDiff)

-    PLOTS_MODIFY_HELP = "Modify display properties of plot metrics files."
+    PLOTS_MODIFY_HELP = (
+        "Modify display properties of data-series plots "
+        "(has no effect on image-type plots)."
+    )
    plots_modify_parser = plots_subparsers.add_parser(
        "modify",
        parents=[parent_parser],
@@ -86,7 +86,7 @@ class CmdRemoteDefault(CmdRemote):
        if self.args.name is None and not self.args.unset:
            conf = self.config.read(self.args.level)
            try:
-                print(conf["core"]["remote"])
+                ui.write(conf["core"]["remote"])
            except KeyError:
                ui.write("No default remote set")
                return 1
@@ -69,10 +69,8 @@ class CmdDataStatus(CmdDataBase):
            if self.args.quiet:
                return bool(st)

-            if self.args.show_json:
-                import json
-
-                ui.write(json.dumps(st))
+            if self.args.json:
+                ui.write_json(st)
                return 0

            if st:
@@ -168,7 +168,7 @@ class TabularData(MutableSequence[Sequence["CellT"]]):
    def render(self, **kwargs: Any):
        from dvc.ui import ui

-        if kwargs.pop("show_csv", False):
+        if kwargs.pop("csv", False):
            ui.write(self.to_csv(), end="")
        else:
            ui.table(self, headers=self.keys(), **kwargs)
@@ -211,8 +211,12 @@ def diff_table(
    precision: int = None,
    round_digits: bool = False,
    on_empty_diff: str = None,
+    a_rev: str = None,
+    b_rev: str = None,
 ) -> TabularData:
-    headers: List[str] = ["Path", title, "Old", "New", "Change"]
+    a_rev = a_rev or "HEAD"
+    b_rev = b_rev or "workspace"
+    headers: List[str] = ["Path", title, a_rev, b_rev, "Change"]
    fill_value = "-"
    td = TabularData(headers, fill_value=fill_value)

@@ -240,8 +244,8 @@ def diff_table(
        td.drop("Change")

    if not old:
-        td.drop("Old")
-        td.rename("New", "Value")
+        td.drop(a_rev)
+        td.rename(b_rev, "Value")

    return td

@@ -256,6 +260,8 @@ def show_diff(
    round_digits: bool = False,
    on_empty_diff: str = None,
    markdown: bool = False,
+    a_rev: str = None,
+    b_rev: str = None,
 ) -> None:
    td = diff_table(
        diff,
@@ -266,6 +272,8 @@ def show_diff(
        precision=precision,
        round_digits=round_digits,
        on_empty_diff=on_empty_diff,
+        a_rev=a_rev,
+        b_rev=b_rev,
    )
    td.render(markdown=markdown)

@@ -76,8 +76,10 @@ class Config(dict):
    APPNAME = "dvc"
    APPAUTHOR = "iterative"

+    SYSTEM_LEVELS = ("system", "global")
+    REPO_LEVELS = ("repo", "local")
    # In the order they shadow each other
-    LEVELS = ("system", "global", "repo", "local")
+    LEVELS = SYSTEM_LEVELS + REPO_LEVELS

    CONFIG = "config"
    CONFIG_LOCAL = "config.local"
@@ -139,7 +141,7 @@ class Config(dict):
            dvc.config.Config: config object.
        """
        config_file = os.path.join(dvc_dir, Config.CONFIG)
-        open(config_file, "w+").close()
+        open(config_file, "w+", encoding="utf-8").close()
        return Config(dvc_dir)

    def load(self, validate=True, config=None):
@@ -286,7 +288,7 @@ class Config(dict):
    def edit(self, level=None, validate=True):
        # NOTE: we write to repo config by default, same as git config
        level = level or "repo"
-        if level in {"repo", "local"} and self.dvc_dir is None:
+        if self.dvc_dir is None and level in self.REPO_LEVELS:
            raise ConfigError("Not inside a DVC repo")

        conf = self.load_one(level)
@@ -156,6 +156,8 @@ SCHEMA = {
                    "grant_write_acp": str,
                    "grant_full_control": str,
                    "cache_regions": bool,
+                    "read_timeout": Coerce(int),
+                    "connect_timeout": Coerce(int),
                    **REMOTE_COMMON,
                },
                "gs": {
@@ -223,13 +225,27 @@ SCHEMA = {
        )
    },
    "state": {
+        "dir": str,
        "row_limit": All(Coerce(int), Range(1)),  # obsoleted
        "row_cleanup_quota": All(Coerce(int), Range(0, 100)),  # obsoleted
    },
+    "index": {
+        "dir": str,
+    },
    "machine": {
        str: {
            "cloud": All(Lower, Choices("aws", "azure")),
+            "region": All(
+                Lower, Choices("us-west", "us-east", "eu-west", "eu-north")
+            ),
+            "image": str,
+            "name": str,
+            "spot": Bool,
+            "spot_price": Coerce(float),
+            "instance_hdd_size": Coerce(int),
            "instance_type": Lower,
+            "instance_gpu": Lower,
+            "ssh_private": str,
            "startup_script": str,
        },
    },
@@ -240,4 +256,13 @@ SCHEMA = {
        Optional("parametrization", default=True): Bool,
    },
    "plots": {"html_template": str},
+    "exp": {
+        "code": str,
+        "data": str,
+        "models": str,
+        "metrics": str,
+        "params": str,
+        "plots": str,
+        "live": str,
+    },
 }
@@ -12,8 +12,6 @@ from dvc.utils import fix_env, is_binary

 logger = logging.getLogger(__name__)

-CREATE_NO_WINDOW = 0x08000000  # only available since Python 3.7 in subprocess.
-

 def _popen(cmd, **kwargs):
    prefix = [sys.executable]
@@ -28,6 +26,7 @@ def _popen(cmd, **kwargs):
 def _spawn_windows(cmd, env):
    from subprocess import (
        CREATE_NEW_PROCESS_GROUP,
+        CREATE_NO_WINDOW,
        STARTF_USESHOWWINDOW,
        STARTUPINFO,
    )
@@ -49,17 +48,17 @@ def _spawn_posix(cmd, env):
    # with PyInstaller has trouble with SystemExit exception and throws
    # errors such as "[26338] Failed to execute script __main__"
    try:
-        pid = os.fork()
+        pid = os.fork()  # pylint: disable=no-member
        if pid > 0:
            return
    except OSError:
        logger.exception("failed at first fork")
        os._exit(1)  # pylint: disable=protected-access

-    os.setsid()
+    os.setsid()  # pylint: disable=no-member

    try:
-        pid = os.fork()
+        pid = os.fork()  # pylint: disable=no-member
        if pid > 0:
            os._exit(0)  # pylint: disable=protected-access
    except OSError:
@@ -59,7 +59,7 @@ class DataCloud:
        from dvc.objects.db import get_odb

        cls, config, path_info = get_cloud_fs(self.repo, name=name)
-        config["tmp_dir"] = self.repo.tmp_dir
+        config["tmp_dir"] = self.repo.index_db_dir
        return get_odb(cls(**config), path_info, **config)

    def push(
@@ -1,3 +1,4 @@
+import logging
 import os
 from collections import defaultdict

@@ -10,6 +11,8 @@ from dvc.utils.serialize import LOADERS, ParseError

 from .base import Dependency

+logger = logging.getLogger(__name__)
+

 class MissingParamsError(DvcException):
    pass
@@ -133,3 +136,20 @@ class ParamsDependency(Dependency):
            )

        return HashInfo(self.PARAM_PARAMS, info)
+
+    def save(self):
+        if not self.exists:
+            raise self.DoesNotExistError(self)
+
+        if not self.isfile and not self.isdir:
+            raise self.IsNotFileOrDirError(self)
+
+        if self.is_empty:
+            logger.warning(f"'{self}' is empty.")
+
+        self.ignore()
+
+        if self.metric or self.plot:
+            self.verify_metric()
+
+        self.hash_info = self.get_hash()
@@ -63,7 +63,7 @@ class RepoDependency(Dependency):
        return {self.PARAM_PATH: self.def_path, self.PARAM_REPO: self.def_repo}

    def download(self, to, jobs=None):
-        from dvc.checkout import checkout
+        from dvc.objects.checkout import checkout

        for odb, objs in self.get_used_objs().items():
            self.repo.cloud.pull(objs, jobs=jobs, odb=odb)
@@ -132,7 +132,7 @@ class RepoDependency(Dependency):
                    pass

            try:
-                staging, staged_obj = stage(
+                staging, _, staged_obj = stage(
                    local_odb,
                    path_info,
                    repo.repo_fs,
@@ -148,9 +148,7 @@ class RepoDependency(Dependency):
            self._staged_objs[rev] = staged_obj
            used_obj_ids[staging].add(staged_obj.hash_info)
            if isinstance(staged_obj, Tree):
-                used_obj_ids[staging].update(
-                    entry.hash_info for _, entry in staged_obj
-                )
+                used_obj_ids[staging].update(oid for _, _, oid in staged_obj)
            return used_obj_ids, staged_obj

    def _check_circular_import(self, odb, obj_ids):
@@ -166,7 +164,7 @@ class RepoDependency(Dependency):
            for hash_info in obj_ids:
                if hash_info.isdir:
                    tree = Tree.load(odb, hash_info)
-                    yield from (odb.get(entry.hash_info) for _, entry in tree)
+                    yield from (odb.get(oid) for _, _, oid in tree)
                else:
                    yield odb.get(hash_info)

@@ -1,10 +1,7 @@
-import collections
 import contextlib
 import logging
 import os
-from typing import TYPE_CHECKING, Any, Union
-
-from voluptuous import MultipleInvalid
+from typing import TYPE_CHECKING, Any, Callable, Tuple, TypeVar, Union

 from dvc.exceptions import DvcException
 from dvc.parsing.versions import LOCKFILE_VERSION, SCHEMA_KWD
@@ -12,23 +9,18 @@ from dvc.stage import serialize
 from dvc.stage.exceptions import (
    StageFileBadNameError,
    StageFileDoesNotExistError,
-    StageFileFormatError,
    StageFileIsNotDvcFileError,
 )
 from dvc.types import AnyPath
 from dvc.utils import relpath
 from dvc.utils.collections import apply_diff
-from dvc.utils.serialize import (
-    dump_yaml,
-    modify_yaml,
-    parse_yaml,
-    parse_yaml_for_update,
-)
+from dvc.utils.serialize import dump_yaml, modify_yaml

 if TYPE_CHECKING:
    from dvc.repo import Repo

 logger = logging.getLogger(__name__)
+_T = TypeVar("_T")

 DVC_FILE = "Dvcfile"
 DVC_FILE_SUFFIX = ".dvc"
@@ -45,10 +37,6 @@ class FileIsGitIgnored(DvcException):
        )


-class LockfileCorruptedError(DvcException):
-    pass
-
-
 class ParametrizedDumpError(DvcException):
    pass

@@ -96,7 +84,7 @@ def check_dvcfile_path(repo, path):


 class FileMixin:
-    SCHEMA = None
+    SCHEMA: Callable[[_T], _T]

    def __init__(self, repo, path, verify=True, **kwargs):
        self.repo = repo
@@ -138,7 +126,11 @@ class FileMixin:
        if self._is_git_ignored():
            raise FileIsGitIgnored(self.path)

-    def _load(self):
+    def load(self, **kwargs: Any) -> Any:
+        d, _ = self._load(**kwargs)
+        return d
+
+    def _load(self, **kwargs: Any) -> Tuple[Any, str]:
        # it raises the proper exceptions by priority:
        # 1. when the file doesn't exists
        # 2. filename is not a DVC file
@@ -155,18 +147,23 @@ class FileMixin:
            raise StageFileIsNotDvcFileError(self.path)

        self._check_gitignored()
-        with self.repo.fs.open(self.path, encoding="utf-8") as fd:
-            stage_text = fd.read()
-        d = parse_yaml(stage_text, self.path)
-        return self.validate(d, self.relpath), stage_text
+        return self._load_yaml(**kwargs)

    @classmethod
-    def validate(cls, d, fname=None):
-        assert isinstance(cls.SCHEMA, collections.abc.Callable)
-        try:
-            return cls.SCHEMA(d)  # pylint: disable=not-callable
-        except MultipleInvalid as exc:
-            raise StageFileFormatError(f"'{fname}' format error: {exc}")
+    def validate(cls, d: _T, fname: str = None) -> _T:
+        from dvc.utils.strictyaml import validate
+
+        return validate(d, cls.SCHEMA, path=fname)  # type: ignore[arg-type]
+
+    def _load_yaml(self, **kwargs: Any) -> Tuple[Any, str]:
+        from dvc.utils import strictyaml
+
+        return strictyaml.load(
+            self.path,
+            self.SCHEMA,  # type: ignore[arg-type]
+            self.repo.fs,
+            **kwargs,
+        )

    def remove(self, force=False):  # pylint: disable=unused-argument
        with contextlib.suppress(FileNotFoundError):
@@ -298,10 +295,7 @@ class PipelineFile(FileMixin):
        if not self.exists():
            return

-        with open(self.path, encoding="utf-8") as f:
-            d = parse_yaml_for_update(f.read(), self.path)
-
-        self.validate(d, self.path)
+        d, _ = self._load_yaml(round_trip=True)
        if stage.name not in d.get("stages", {}):
            return

@@ -343,34 +337,25 @@ def migrate_lock_v1_to_v2(d, version_info):
    d["stages"] = stages


+def lockfile_schema(data: _T) -> _T:
+    schema = get_lockfile_schema(data)
+    return schema(data)
+
+
 class Lockfile(FileMixin):
-    @classmethod
-    def validate(cls, d, fname=None):
-        schema = get_lockfile_schema(d)
-        try:
-            return schema(d)
-        except MultipleInvalid as exc:
-            raise StageFileFormatError(f"'{fname}' format error: {exc}")
+    SCHEMA = staticmethod(lockfile_schema)  # type: ignore[assignment]

    def _verify_filename(self):
        pass  # lockfile path is hardcoded, so no need to verify here

-    def _load(self):
+    def _load(self, **kwargs: Any):
        try:
-            return super()._load()
+            return super()._load(**kwargs)
        except StageFileDoesNotExistError:
            # we still need to account for git-ignored dvc.lock file
            # even though it may not exist or have been .dvcignored
            self._check_gitignored()
            return {}, ""
-        except StageFileFormatError as exc:
-            raise LockfileCorruptedError(
-                f"Lockfile '{self.relpath}' is corrupted."
-            ) from exc
-
-    def load(self):
-        d, _ = self._load()
-        return d

    @property
    def latest_version_info(self):
@@ -409,10 +394,7 @@ class Lockfile(FileMixin):
        if not self.exists():
            return

-        with open(self.path, encoding="utf-8") as f:
-            d = parse_yaml_for_update(f.read(), self.path)
-        self.validate(d, self.path)
-
+        d, _ = self._load_yaml(round_trip=True)
        version = LOCKFILE_VERSION.from_dict(d)
        data = d if version == LOCKFILE_VERSION.V1 else d.get("stages", {})
        if stage.name not in data:
@@ -364,3 +364,8 @@ class CircularImportError(DvcException):
            f"'{dep}' contains invalid circular import. "
            f"DVC repo '{a}' already imports from '{b}'."
        )
+
+
+class PrettyDvcException(DvcException):
+    def __pretty_exc__(self, **kwargs):
+        """Print prettier exception message."""
@@ -11,7 +11,7 @@ from dvc.path_info import CloudURLInfo
 from dvc.scheme import Schemes
 from dvc.utils import format_link

-from .fsspec_wrapper import ObjectFSWrapper
+from .fsspec_wrapper import CallbackMixin, ObjectFSWrapper

 logger = logging.getLogger(__name__)
 _DEFAULT_CREDS_STEPS = (
@@ -39,7 +39,7 @@ def _az_config():


 # pylint:disable=abstract-method
-class AzureFileSystem(ObjectFSWrapper):
+class AzureFileSystem(CallbackMixin, ObjectFSWrapper):
    scheme = Schemes.AZURE
    PATH_CLS = CloudURLInfo
    PARAM_CHECKSUM = "etag"
@@ -1,12 +1,17 @@
+import contextlib
 import logging
+import os
 from concurrent.futures import ThreadPoolExecutor, as_completed
-from functools import partial, partialmethod
+from functools import partialmethod
 from multiprocessing import cpu_count
 from typing import Any, ClassVar, Dict, FrozenSet, Optional

+from tqdm.utils import CallbackIOWrapper
+
 from dvc.exceptions import DvcException
 from dvc.path_info import URLInfo
-from dvc.progress import Tqdm
+from dvc.progress import DEFAULT_CALLBACK, FsspecCallback
+from dvc.ui import ui
 from dvc.utils import tmp_fname
 from dvc.utils.fs import makedirs, move

@@ -170,12 +175,6 @@ class BaseFileSystem:
        """
        raise NotImplementedError

-    def ls(self, path_info, detail=False):
-        raise RemoteActionNotImplemented("ls", self.scheme)
-
-    def find(self, path_info, detail=False, prefix=None):
-        raise RemoteActionNotImplemented("find", self.scheme)
-
    def is_empty(self, path_info):
        return False

@@ -223,128 +222,158 @@ class BaseFileSystem:
        to_info,
        total=None,
        desc=None,
+        callback=None,
        no_progress_bar=False,
        **pbar_args,
    ):
        is_file_obj = hasattr(from_info, "read")
-        method = "upload_fobj" if is_file_obj else "_upload"
+        method = "upload_fobj" if is_file_obj else "put_file"
        if not hasattr(self, method):
            raise RemoteActionNotImplemented(method, self.scheme)

        if to_info.scheme != self.scheme:
            raise NotImplementedError

-        logger.debug("Uploading '%s' to '%s'", from_info, to_info)
-        if is_file_obj:
-            with Tqdm.wrapattr(
-                from_info,
-                "read",
+        if not is_file_obj:
+            desc = desc or from_info.name
+
+        stack = contextlib.ExitStack()
+        if not callback:
+            pbar = ui.progress(
+                desc=desc,
                disable=no_progress_bar,
                bytes=True,
-                total=total,
-                desc=desc,
+                total=total or -1,
                **pbar_args,
-            ) as wrapped:
+            )
+            stack.enter_context(pbar)
+            callback = pbar.as_callback()
+            if total:
+                callback.set_size(total)
+
+        with stack:
+            if is_file_obj:
+                wrapped = CallbackIOWrapper(
+                    callback.relative_update, from_info
+                )
                # `size` is used to provide hints to the WebdavFileSystem
                # for legacy servers.
                # pylint: disable=no-member
                return self.upload_fobj(wrapped, to_info, size=total)

-        if from_info.scheme != "local":
-            raise NotImplementedError
+            if from_info.scheme != "local":
+                raise NotImplementedError

-        name = desc or from_info.name
-        return self._upload(  # noqa, pylint: disable=no-member
-            from_info.fspath,
-            to_info,
-            name=name,
-            no_progress_bar=no_progress_bar,
-            **pbar_args,
-        )
+            logger.debug("Uploading '%s' to '%s'", from_info, to_info)
+            # pylint: disable=no-member
+            return self.put_file(
+                os.fspath(from_info), to_info, callback=callback
+            )

    def download(
        self,
        from_info,
        to_info,
        name=None,
+        callback=None,
        no_progress_bar=False,
        jobs=None,
        _only_file=False,
        **kwargs,
    ):
-        if not hasattr(self, "_download"):
-            raise RemoteActionNotImplemented("download", self.scheme)
+        if not hasattr(self, "get_file"):
+            raise RemoteActionNotImplemented("get_file", self.scheme)

        if from_info.scheme != self.scheme:
            raise NotImplementedError

-        if to_info.scheme == self.scheme != "local":
-            self.copy(from_info, to_info)
-            return 0
-
        if to_info.scheme != "local":
            raise NotImplementedError

-        if not _only_file and self.isdir(from_info):
-            return self._download_dir(
-                from_info, to_info, name, no_progress_bar, jobs, **kwargs
+        download_dir = not _only_file and self.isdir(from_info)
+
+        desc = name or to_info.name
+        stack = contextlib.ExitStack()
+        if not callback:
+            pbar_kwargs = {"unit": "Files"} if download_dir else {}
+            pbar = ui.progress(
+                total=-1,
+                desc="Downloading directory" if download_dir else desc,
+                bytes=not download_dir,
+                disable=no_progress_bar,
+                **pbar_kwargs,
            )
-        return self._download_file(from_info, to_info, name, no_progress_bar)
+            stack.enter_context(pbar)
+            callback = pbar.as_callback()
+
+        with stack:
+            if download_dir:
+                return self._download_dir(
+                    from_info, to_info, callback=callback, jobs=jobs, **kwargs
+                )
+            return self._download_file(from_info, to_info, callback=callback)

    download_file = partialmethod(download, _only_file=True)

    def _download_dir(
-        self, from_info, to_info, name, no_progress_bar, jobs, **kwargs
+        self,
+        from_info,
+        to_info,
+        callback=DEFAULT_CALLBACK,
+        jobs=None,
+        **kwargs,
    ):
        from_infos = list(self.walk_files(from_info, **kwargs))
        if not from_infos:
            makedirs(to_info, exist_ok=True)
            return None
+
        to_infos = (
            to_info / info.relative_to(from_info) for info in from_infos
        )
+        callback.set_size(len(from_infos))

-        with Tqdm(
-            total=len(from_infos),
-            desc="Downloading directory",
-            unit="Files",
-            disable=no_progress_bar,
-        ) as pbar:
-            download_files = pbar.wrap_fn(
-                partial(self._download_file, name=name, no_progress_bar=True)
-            )
-            max_workers = jobs or self.jobs
-            with ThreadPoolExecutor(max_workers=max_workers) as executor:
-                futures = [
-                    executor.submit(download_files, from_info, to_info)
-                    for from_info, to_info in zip(from_infos, to_infos)
-                ]
+        download_files = FsspecCallback.wrap_fn(callback, self._download_file)
+        max_workers = jobs or self.jobs
+        with ThreadPoolExecutor(max_workers=max_workers) as executor:
+            futures = [
+                executor.submit(download_files, from_info, to_info)
+                for from_info, to_info in zip(from_infos, to_infos)
+            ]

-                # NOTE: unlike pulling/fetching cache, where we need to
-                # download everything we can, not raising an error here might
-                # turn very ugly, as the user might think that he has
-                # downloaded a complete directory, while having a partial one,
-                # which might cause unexpected results in his pipeline.
-                for future in as_completed(futures):
-                    # NOTE: executor won't let us raise until all futures that
-                    # it has are finished, so we need to cancel them ourselves
-                    # before re-raising.
-                    exc = future.exception()
-                    if exc:
-                        for entry in futures:
-                            entry.cancel()
-                        raise exc
+            # NOTE: unlike pulling/fetching cache, where we need to
+            # download everything we can, not raising an error here might
+            # turn very ugly, as the user might think that he has
+            # downloaded a complete directory, while having a partial one,
+            # which might cause unexpected results in his pipeline.
+            for future in as_completed(futures):
+                # NOTE: executor won't let us raise until all futures that
+                # it has are finished, so we need to cancel them ourselves
+                # before re-raising.
+                exc = future.exception()
+                if exc:
+                    for entry in futures:
+                        entry.cancel()
+                    raise exc

-    def _download_file(self, from_info, to_info, name, no_progress_bar):
+    def _download_file(
+        self,
+        from_info,
+        to_info,
+        callback=DEFAULT_CALLBACK,
+    ):
        makedirs(to_info.parent, exist_ok=True)
-
-        logger.debug("Downloading '%s' to '%s'", from_info, to_info)
-        name = name or to_info.name
-
        tmp_file = tmp_fname(to_info)

-        self._download(  # noqa, pylint: disable=no-member
-            from_info, tmp_file, name=name, no_progress_bar=no_progress_bar
-        )
+        logger.debug("Downloading '%s' to '%s'", from_info, to_info)
+        try:
+            # noqa, pylint: disable=no-member
+            self.get_file(from_info, tmp_file, callback=callback)
+        except Exception:  # pylint: disable=broad-except
+            # do we need to rollback makedirs for previously not-existing
+            # directories?
+            with contextlib.suppress(FileNotFoundError):
+                os.unlink(tmp_file)
+            raise

        move(tmp_file, to_info)
@@ -6,6 +6,7 @@ from dvc.exceptions import OutputNotFoundError
 from dvc.path_info import PathInfo
 from dvc.utils import relpath

+from ..progress import DEFAULT_CALLBACK
 from ._metadata import Metadata
 from .base import BaseFileSystem

@@ -57,9 +58,9 @@ class DvcFileSystem(BaseFileSystem):  # pylint:disable=abstract-method
        out.get_dir_cache(remote=remote)
        if out.obj is None:
            raise FileNotFoundError
-        obj = out.obj.trie.get(key)
-        if obj:
-            return obj.hash_info
+        (_, oid) = out.obj.trie.get(key) or (None, None)
+        if oid:
+            return oid
        raise FileNotFoundError

    def _get_fs_path(self, path: PathInfo, remote=None):
@@ -153,7 +154,7 @@ class DvcFileSystem(BaseFileSystem):  # pylint:disable=abstract-method
        self._fetch_dir(out, **kwargs)

        base = out.path_info.parts
-        for key, _ in out.obj:  # noqa: B301
+        for key, _, _ in out.obj:  # noqa: B301
            trie[base + key] = None

    def _walk(self, root, trie, topdown=True, **kwargs):
@@ -165,16 +166,19 @@ class DvcFileSystem(BaseFileSystem):  # pylint:disable=abstract-method
            self._add_dir(trie, out, **kwargs)

        root_len = len(root.parts)
-        for key, out in trie.iteritems(prefix=root.parts):  # noqa: B301
-            if key == root.parts:
-                continue
+        try:
+            for key, out in trie.iteritems(prefix=root.parts):  # noqa: B301
+                if key == root.parts:
+                    continue

-            name = key[root_len]
-            if len(key) > root_len + 1 or (out and out.is_dir_checksum):
-                dirs.add(name)
-                continue
+                name = key[root_len]
+                if len(key) > root_len + 1 or (out and out.is_dir_checksum):
+                    dirs.add(name)
+                    continue

-            files.append(name)
+                files.append(name)
+        except KeyError:
+            pass

        assert topdown
        dirs = list(dirs)
@@ -243,23 +247,25 @@ class DvcFileSystem(BaseFileSystem):  # pylint:disable=abstract-method
        meta = self.metadata(path_info)
        ret = {"type": "directory" if meta.isdir else "file"}
        if meta.is_output and len(meta.outs) == 1 and meta.outs[0].hash_info:
-            hash_info = meta.outs[0].hash_info
-            ret["size"] = hash_info.size
-            ret[hash_info.name] = hash_info.value
+            out = meta.outs[0]
+            ret["size"] = out.meta.size
+            ret[out.hash_info.name] = out.hash_info.value
        elif meta.part_of_output:
            (out,) = meta.outs
            key = path_info.relative_to(out.path_info).parts
-            obj = out.obj.trie.get(key)
-            if obj:
-                ret["size"] = obj.size
-                ret[obj.hash_info.name] = obj.hash_info.value
+            (obj_meta, oid) = out.obj.trie.get(key) or (None, None)
+            if oid:
+                ret["size"] = obj_meta.size if obj_meta else 0
+                ret[oid.name] = oid.value

        return ret

-    def _download(self, from_info, to_file, **kwargs):
+    def get_file(
+        self, from_info, to_file, callback=DEFAULT_CALLBACK, **kwargs
+    ):
        fs, path = self._get_fs_path(from_info)
-        fs._download(  # pylint: disable=protected-access
-            path, to_file, **kwargs
+        fs.get_file(  # pylint: disable=protected-access
+            path, to_file, callback=callback, **kwargs
        )

    def checksum(self, path_info):
@@ -1,13 +1,37 @@
 import os
 import shutil
 from functools import lru_cache
+from typing import (
+    IO,
+    TYPE_CHECKING,
+    Any,
+    Dict,
+    Iterator,
+    Optional,
+    Union,
+    overload,
+)

 from funcy import cached_property
+from tqdm.utils import CallbackIOWrapper

-from dvc.progress import Tqdm
+from dvc.path_info import URLInfo
+from dvc.progress import DEFAULT_CALLBACK

 from .base import BaseFileSystem
-from .local import LocalFileSystem
+
+FSPath = URLInfo
+AnyFSPath = Union[FSPath, str]
+
+if TYPE_CHECKING:
+    from typing import Iterable
+
+    from typing_extensions import Literal
+
+
+# An info() entry, might evolve to a TypedDict
+# in the future (e.g for properly type 'size' etc).
+Entry = Dict[str, Any]


 # pylint: disable=no-member
@@ -19,18 +43,8 @@ class FSSpecWrapper(BaseFileSystem):
        self.fs_args = {"skip_instance_cache": True}
        self.fs_args.update(self._prepare_credentials(**kwargs))

-    @cached_property
-    def fs(self):
-        raise NotImplementedError
-
-    def _with_bucket(self, path):
-        return str(path)
-
-    def _strip_bucket(self, entry):
-        return entry
-
    @staticmethod
-    def _get_kwargs_from_urls(urlpath):
+    def _get_kwargs_from_urls(urlpath: str) -> "Dict[str, Any]":
        from fsspec.utils import infer_storage_options

        options = infer_storage_options(urlpath)
@@ -38,6 +52,28 @@ class FSSpecWrapper(BaseFileSystem):
        options.pop("protocol", None)
        return options

+    @cached_property
+    def fs(self):
+        raise NotImplementedError
+
+    def _with_bucket(self, path: AnyFSPath) -> str:
+        return str(path)
+
+    def _strip_bucket(self, entry: str) -> str:
+        return entry
+
+    @overload
+    def _strip_buckets(
+        self, entries: "Iterable[Entry]", detail: "Literal[True]"
+    ) -> "Iterator[Entry]":
+        ...
+
+    @overload
+    def _strip_buckets(
+        self, entries: "Iterable[str]", detail: "Literal[False]" = False
+    ) -> "Iterator[str]":
+        ...
+
    def _strip_buckets(self, entries, detail=False):
        for entry in entries:
            if detail:
@@ -47,59 +83,91 @@ class FSSpecWrapper(BaseFileSystem):
                entry = self._strip_bucket(entry)
            yield entry

-    def _entry_hook(self, entry):
+    def _entry_hook(self, entry: "Entry") -> "Entry":
        """Simple hook method to be overridden when wanted to process
        entries within info() and ls(detail=True) calls"""
        return entry

    def _prepare_credentials(
-        self, **config
-    ):  # pylint: disable=unused-argument
+        self, **config: Dict[str, Any]  # pylint: disable=unused-argument
+    ) -> Dict[str, Any]:
        """Prepare the arguments for authentication to the
        host filesystem"""
        return {}

-    def _isdir(self, path_info):
+    def _isdir(self, path_info: FSPath) -> bool:
        return self.fs.isdir(self._with_bucket(path_info))

-    def isdir(self, path_info):
+    def isdir(self, path_info: FSPath) -> bool:
        try:
            return self._isdir(path_info)
        except FileNotFoundError:
            return False

-    def isfile(self, path_info):
+    def isfile(self, path_info: FSPath) -> bool:
        try:
            return not self._isdir(path_info)
        except FileNotFoundError:
            return False

-    def is_empty(self, path_info):
+    def is_empty(self, path_info: FSPath) -> bool:
        entry = self.info(path_info)
        if entry["type"] == "directory":
            return not self.fs.ls(self._with_bucket(path_info))
        return entry["size"] == 0

    def open(
-        self, path_info, mode="r", **kwargs
-    ):  # pylint: disable=arguments-differ
+        self,
+        path_info: FSPath,
+        mode: str = "r",
+        encoding: Optional[str] = None,
+        **kwargs,
+    ) -> "IO":  # pylint: disable=arguments-differ
        return self.fs.open(self._with_bucket(path_info), mode=mode)

-    def checksum(self, path_info):
+    def checksum(self, path_info: FSPath) -> str:
        return self.fs.checksum(self._with_bucket(path_info))

-    def copy(self, from_info, to_info):
+    def copy(self, from_info: FSPath, to_info: FSPath) -> None:
        self.makedirs(to_info.parent)
        self.fs.copy(self._with_bucket(from_info), self._with_bucket(to_info))

-    def exists(self, path_info) -> bool:
+    def exists(self, path_info: FSPath) -> bool:
        return self.fs.exists(self._with_bucket(path_info))

+    @overload
+    def ls(
+        self, path_info: FSPath, detail: "Literal[True]"
+    ) -> "Iterator[Entry]":
+        ...
+
+    @overload
+    def ls(self, path_info: FSPath, detail: "Literal[False]") -> Iterator[str]:
+        ...
+
    def ls(self, path_info, detail=False):
        path = self._with_bucket(path_info)
        files = self.fs.ls(path, detail=detail)
        yield from self._strip_buckets(files, detail=detail)

+    @overload
+    def find(
+        self,
+        path_info: FSPath,
+        detail: "Literal[True]",
+        prefix: Optional[bool],
+    ) -> "Iterator[Entry]":
+        ...
+
+    @overload
+    def find(
+        self,
+        path_info: FSPath,
+        detail: "Literal[False]",
+        prefix: Optional[bool],
+    ) -> Iterator[str]:
+        ...
+
    # pylint: disable=unused-argument
    def find(self, path_info, detail=False, prefix=None):
        path = self._with_bucket(path_info)
@@ -109,65 +177,56 @@ class FSSpecWrapper(BaseFileSystem):

        yield from self._strip_buckets(files, detail=detail)

-    def walk_files(self, path_info, **kwargs):
+    def walk_files(self, path_info: FSPath, **kwargs) -> Iterator[FSPath]:
        for file in self.find(path_info, **kwargs):
            yield path_info.replace(path=file)

-    def move(self, from_info, to_info):
+    def move(self, from_info: FSPath, to_info: FSPath) -> None:
        self.fs.move(self._with_bucket(from_info), self._with_bucket(to_info))

-    def remove(self, path_info):
+    def remove(self, path_info: FSPath) -> None:
        self.fs.rm_file(self._with_bucket(path_info))

-    def info(self, path_info):
+    def info(self, path_info: FSPath) -> "Entry":
        info = self.fs.info(self._with_bucket(path_info)).copy()
        info = self._entry_hook(info)
        info["name"] = self._strip_bucket(info["name"])
        return info

-    def makedirs(self, path_info, **kwargs):
+    def makedirs(self, path_info: FSPath, **kwargs) -> None:
        self.fs.makedirs(
            self._with_bucket(path_info), exist_ok=kwargs.pop("exist_ok", True)
        )

-    def upload_fobj(self, fobj, to_info, **kwargs):
-        self.makedirs(to_info.parent)
-        with self.open(to_info, "wb") as fdest:
-            shutil.copyfileobj(fobj, fdest, length=fdest.blocksize)
-
-    def _upload(
-        self, from_file, to_info, name=None, no_progress_bar=False, **kwargs
-    ):
-        self.makedirs(to_info.parent)
-        size = os.path.getsize(from_file)
-        with open(from_file, "rb") as fobj:
-            with Tqdm.wrapattr(
-                fobj,
-                "read",
-                disable=no_progress_bar,
-                bytes=True,
-                total=size,
-                desc=name,
-            ) as wrapped:
-                self.upload_fobj(wrapped, to_info, size=size)
+    def put_file(
+        self,
+        from_file: FSPath,
+        to_info: FSPath,
+        callback: Any = DEFAULT_CALLBACK,
+        **kwargs,
+    ) -> None:
+        self.fs.put_file(
+            from_file, self._with_bucket(to_info), callback=callback, **kwargs
+        )
        self.fs.invalidate_cache(self._with_bucket(to_info.parent))

-    def _download(
-        self, from_info, to_file, name=None, no_progress_bar=False, **pbar_args
-    ):
-        total = self.getsize(self._with_bucket(from_info))
-        with self.open(from_info, "rb") as fobj:
-            with Tqdm.wrapattr(
-                fobj,
-                "read",
-                desc=name,
-                disable=no_progress_bar,
-                bytes=True,
-                total=total,
-                **pbar_args,
-            ) as wrapped:
-                with open(to_file, "wb") as fdest:
-                    shutil.copyfileobj(wrapped, fdest, length=fobj.blocksize)
+    def get_file(
+        self,
+        from_info: FSPath,
+        to_info: FSPath,
+        callback: Any = DEFAULT_CALLBACK,
+        **kwargs,
+    ) -> None:
+        self.fs.get_file(
+            self._with_bucket(from_info), to_info, callback=callback, **kwargs
+        )
+
+    def upload_fobj(self, fobj: IO, to_info: FSPath, **kwargs) -> None:
+        self.makedirs(to_info.parent)
+        with self.open(to_info, "wb") as fdest:
+            shutil.copyfileobj(
+                fobj, fdest, length=getattr(fdest, "blocksize", None)
+            )


 # pylint: disable=abstract-method
@@ -175,21 +234,21 @@ class ObjectFSWrapper(FSSpecWrapper):
    TRAVERSE_PREFIX_LEN = 3

    @lru_cache(512)
-    def _with_bucket(self, path):
+    def _with_bucket(self, path: AnyFSPath) -> str:
        if isinstance(path, self.PATH_CLS):
            return f"{path.bucket}/{path.path}"
-        return path
+        return str(path)

-    def _strip_bucket(self, entry):
+    def _strip_bucket(self, entry: str) -> str:
        try:
            bucket, path = entry.split("/", 1)
        except ValueError:
            # If there is no path attached, only returns
            # the bucket (top-level).
-            bucket, path = entry, None
+            bucket, path = entry, ""
        return path or bucket

-    def makedirs(self, path_info, **kwargs):
+    def makedirs(self, path_info: FSPath, **kwargs) -> None:
        # For object storages make this method a no-op. The original
        # fs.makedirs() method will only check if the bucket exists
        # and create if it doesn't though we don't want to support
@@ -197,7 +256,7 @@ class ObjectFSWrapper(FSSpecWrapper):
        # simply ignore all mkdir()/makedirs() calls.
        return None

-    def _isdir(self, path_info):
+    def _isdir(self, path_info: FSPath) -> bool:
        # Directory in object storages are interpreted differently
        # among different fsspec providers, so this logic is a temporary
        # measure for us to adapt as of now. It checks whether it is a
@@ -232,7 +291,9 @@ class ObjectFSWrapper(FSSpecWrapper):
        if len(files) == 1 and files[0] == path and self.isdir(path_info):
            return None

-        yield from self._strip_buckets(files, detail=detail)
+        yield from self._strip_buckets(  # pylint: disable=not-an-iterable
+            files, detail=detail
+        )


 # pylint: disable=arguments-differ
@@ -256,42 +317,38 @@ class NoDirectoriesMixin:
        raise NotImplementedError


-_LOCAL_FS = LocalFileSystem()
-
-
 class CallbackMixin:
-    """Use the native ``get_file()``/``put_file()`` APIs
-    if the target filesystem supports callbacks."""
+    """Provides callback support for the filesystem that don't support yet."""

-    def _upload(
-        self, from_file, to_info, name=None, no_progress_bar=False, **pbar_args
+    def put_file(
+        self,
+        from_file,
+        to_info,
+        callback=DEFAULT_CALLBACK,
+        **kwargs,
    ):
-        with Tqdm(
-            desc=name,
-            disable=no_progress_bar,
-            bytes=True,
-            total=-1,
-            **pbar_args,
-        ) as pbar:
-            self.fs.put_file(
-                os.fspath(from_file),
-                self._with_bucket(to_info),
-                callback=pbar.as_callback(_LOCAL_FS, from_file),
-            )
-        self.fs.invalidate_cache(self._with_bucket(to_info.parent))
+        """Add compatibility support for Callback."""
+        # pylint: disable=protected-access
+        self.makedirs(to_info.parent)
+        size = os.path.getsize(from_file)
+        with open(from_file, "rb") as fobj:
+            callback.set_size(size)
+            wrapped = CallbackIOWrapper(callback.relative_update, fobj)
+            self.upload_fobj(wrapped, to_info)
+            self.fs.invalidate_cache(self._with_bucket(to_info.parent))

-    def _download(
-        self, from_info, to_file, name=None, no_progress_bar=False, **pbar_args
+    def get_file(
+        self,
+        from_info,
+        to_info,
+        callback=DEFAULT_CALLBACK,
+        **kwargs,
    ):
-        with Tqdm(
-            desc=name,
-            disable=no_progress_bar,
-            bytes=True,
-            total=-1,
-            **pbar_args,
-        ) as pbar:
-            self.fs.get_file(
-                self._with_bucket(from_info),
-                os.fspath(to_file),
-                callback=pbar.as_callback(self, from_info),
-            )
+        # pylint: disable=protected-access
+        total: int = self.getsize(from_info)
+        if total:
+            callback.set_size(total)
+
+        with self.open(from_info, "rb") as fobj, open(to_info, "wb") as fdest:
+            wrapped = CallbackIOWrapper(callback.relative_update, fobj)
+            shutil.copyfileobj(wrapped, fdest, length=fobj.blocksize)
@@ -5,14 +5,14 @@ import re
 import threading
 from urllib.parse import urlparse

-from funcy import cached_property, retry, wrap_prop
+from funcy import cached_property, wrap_prop

 from dvc.exceptions import DvcException
 from dvc.path_info import CloudURLInfo
 from dvc.scheme import Schemes
 from dvc.utils import format_link, tmp_fname

-from .fsspec_wrapper import CallbackMixin, FSSpecWrapper
+from .fsspec_wrapper import FSSpecWrapper

 logger = logging.getLogger(__name__)
 FOLDER_MIME_TYPE = "application/vnd.google-apps.folder"
@@ -34,36 +34,6 @@ class GDriveAuthError(DvcException):
        super().__init__(message)


-def _gdrive_retry(func):
-    def should_retry(exc):
-        from pydrive2.files import ApiRequestError
-
-        if not isinstance(exc, ApiRequestError):
-            return False
-
-        error_code = exc.error.get("code", 0)
-        result = False
-        if 500 <= error_code < 600:
-            result = True
-
-        if error_code == 403:
-            result = exc.GetField("reason") in [
-                "userRateLimitExceeded",
-                "rateLimitExceeded",
-            ]
-        if result:
-            logger.debug(f"Retrying GDrive API call, error: {exc}.")
-
-        return result
-
-    # 16 tries, start at 0.5s, multiply by golden ratio, cap at 20s
-    return retry(
-        16,
-        timeout=lambda a: min(0.5 * 1.618 ** a, 20),
-        filter_errors=should_retry,
-    )(func)
-
-
 class GDriveURLInfo(CloudURLInfo):
    def __init__(self, url):
        super().__init__(url)
@@ -79,9 +49,7 @@ class GDriveURLInfo(CloudURLInfo):
        self._spath = re.sub("/{2,}", "/", self._spath.rstrip("/"))


-class GDriveFileSystem(
-    CallbackMixin, FSSpecWrapper
-):  # pylint:disable=abstract-method
+class GDriveFileSystem(FSSpecWrapper):  # pylint:disable=abstract-method
    scheme = Schemes.GDRIVE
    PATH_CLS = GDriveURLInfo
    PARAM_CHECKSUM = "checksum"
@@ -221,7 +189,7 @@ class GDriveFileSystem(
            temporary_save_path = self._gdrive_service_credentials_path

        if is_credentials_temp:
-            with open(temporary_save_path, "w") as cred_file:
+            with open(temporary_save_path, "w", encoding="utf-8") as cred_file:
                cred_file.write(
                    os.getenv(GDriveFileSystem.GDRIVE_CREDENTIALS_DATA)
                )
@@ -298,6 +266,15 @@ class GDriveFileSystem(

        return super()._with_bucket(path)

+    def _strip_bucket(self, entry):
+        try:
+            bucket, path = entry.split("/", 1)
+        except ValueError:
+            # If there is no path attached, only returns
+            # the bucket (top-level).
+            bucket, path = entry, None
+        return path or bucket
+
    def upload_fobj(self, fobj, to_info, **kwargs):
        rpath = self._with_bucket(to_info)
        self.makedirs(os.path.dirname(rpath))
@@ -1,8 +1,11 @@
 import errno
 import os

+from tqdm.utils import CallbackIOWrapper
+
 from dvc.utils import is_exec, relpath

+from ..progress import DEFAULT_CALLBACK
 from .base import BaseFileSystem


@@ -116,16 +119,18 @@ class GitFileSystem(BaseFileSystem):  # pylint:disable=abstract-method
                # NOTE: os.path.join is ~5.5 times slower
                yield f"{root}{os.sep}{file}"

-    def _download(
-        self, from_info, to_file, name=None, no_progress_bar=False, **kwargs
+    def get_file(
+        self, from_info, to_file, callback=DEFAULT_CALLBACK, **kwargs
    ):
        import shutil

-        from dvc.progress import Tqdm
+        total = self.getsize(from_info)
+        if total:
+            callback.set_size(total)

-        with open(to_file, "wb+") as to_fobj:
-            with Tqdm.wrapattr(
-                to_fobj, "write", desc=name, disable=no_progress_bar
-            ) as wrapped:
-                with self.open(from_info, "rb", **kwargs) as from_fobj:
-                    shutil.copyfileobj(from_fobj, wrapped)
+        with self.open(from_info, "rb", **kwargs) as from_fobj:
+            with open(to_file, "wb+") as to_fobj:
+                wrapped = CallbackIOWrapper(
+                    callback.relative_update, from_fobj
+                )
+                shutil.copyfileobj(wrapped, to_fobj)
@@ -6,17 +6,16 @@ from funcy import cached_property, wrap_prop
 from dvc.path_info import CloudURLInfo
 from dvc.scheme import Schemes

-from .fsspec_wrapper import ObjectFSWrapper
-
-
 # pylint:disable=abstract-method
-class GSFileSystem(ObjectFSWrapper):
+from .fsspec_wrapper import CallbackMixin, ObjectFSWrapper
+
+
+class GSFileSystem(CallbackMixin, ObjectFSWrapper):
    scheme = Schemes.GS
    PATH_CLS = CloudURLInfo
    REQUIRES = {"gcsfs": "gcsfs"}
    PARAM_CHECKSUM = "etag"
    DETAIL_FIELDS = frozenset(("etag", "size"))
-    TRAVERSE_PREFIX_LEN = 2

    def _prepare_credentials(self, **config):
        login_info = {"consistency": None}
@@ -1,285 +1,90 @@
-import errno
-import io
-import logging
 import os
 import re
-import shutil
 import subprocess
-from collections import deque
-from contextlib import closing, contextmanager
+import threading
+
+from funcy import cached_property, wrap_prop

-from dvc.hash_info import HashInfo
-from dvc.progress import Tqdm
 from dvc.scheme import Schemes
-from dvc.utils import fix_env, tmp_fname
+from dvc.utils import fix_env

-from .base import BaseFileSystem, RemoteCmdError
-from .pool import get_connection
+from .fsspec_wrapper import CallbackMixin, FSSpecWrapper

-logger = logging.getLogger(__name__)
+CHECKSUM_REGEX = re.compile(r".*\t.*\t(?P<checksum>.*)")


-def _hadoop_fs(cmd, user=None):
-    cmd = "hadoop fs -" + cmd
-    if user:
-        cmd = f"HADOOP_USER_NAME={user} " + cmd
-
-    # NOTE: close_fds doesn't work with redirected stdin/stdout/stderr.
-    # See https://github.com/iterative/dvc/issues/1197.
-    close_fds = os.name != "nt"
-
-    executable = os.getenv("SHELL") if os.name != "nt" else None
-    p = subprocess.Popen(
-        cmd,
-        shell=True,
-        close_fds=close_fds,
-        executable=executable,
-        env=fix_env(os.environ),
-        stdin=subprocess.PIPE,
-        stdout=subprocess.PIPE,
-        stderr=subprocess.PIPE,
-    )
-    out, err = p.communicate()
-    if p.returncode != 0:
-        raise RemoteCmdError("hdfs", cmd, p.returncode, err)
-    return out.decode("utf-8")
-
-
-def _group(regex, s, gname):
-    match = re.match(regex, s)
-    assert match is not None
-    return match.group(gname)
-
-
-def _hadoop_fs_checksum(path_info):
-    # NOTE: pyarrow doesn't support checksum, so we need to use hadoop
-    regex = r".*\t.*\t(?P<checksum>.*)"
-    stdout = _hadoop_fs(f"checksum {path_info.url}", user=path_info.user)
-    return _group(regex, stdout, "checksum")
-
-
-class HDFSFileSystem(BaseFileSystem):
+# pylint: disable=abstract-method
+class HDFSFileSystem(CallbackMixin, FSSpecWrapper):
    scheme = Schemes.HDFS
-    REQUIRES = {"pyarrow": "pyarrow"}
-    REGEX = r"^hdfs://((?P<user>.*)@)?.*$"
+    REQUIRES = {"fsspec": "fsspec", "pyarrow": "pyarrow"}
    PARAM_CHECKSUM = "checksum"
-    TRAVERSE_PREFIX_LEN = 2

-    BLOCK_SIZE = 2 ** 26  # 128MB
-
-    def __init__(self, **config):
-        super().__init__(**config)
-
-        self.host = config["host"]
-        self.user = config.get("user")
-        self.port = config.get("port")
-
-        self.kerb_ticket = config.get("kerb_ticket")
+    def _with_bucket(self, path):
+        if isinstance(path, self.PATH_CLS):
+            return path.path
+        return super()._with_bucket(path)

    @staticmethod
    def _get_kwargs_from_urls(urlpath):
-        from fsspec.implementations.hdfs import PyArrowHDFS
+        from fsspec.implementations.arrow import HadoopFileSystem

        # pylint:disable=protected-access
-        return PyArrowHDFS._get_kwargs_from_urls(urlpath)
+        return HadoopFileSystem._get_kwargs_from_urls(urlpath)

-    def hdfs(self, path_info):
-        import pyarrow.fs
+    def _prepare_credentials(self, **config):
+        return config

-        # NOTE: HadoopFileSystem is not meant to be closed by us and doesn't
-        # have close() method or alternative, so we add a noop one to satisfy
-        # our connection pool.
-        class HDFSConnection(pyarrow.fs.HadoopFileSystem):
-            def close(self):
-                pass
+    @wrap_prop(threading.Lock())
+    @cached_property
+    def fs(self):
+        from fsspec.implementations.arrow import HadoopFileSystem

-        return get_connection(
-            HDFSConnection,
-            path_info.host,
-            path_info.port,
-            user=path_info.user,
-            kerb_ticket=self.kerb_ticket,
-        )
-
-    @contextmanager
-    def open(self, path_info, mode="r", encoding=None, **kwargs):
-        assert mode in {"r", "rt", "rb"}
-
-        try:
-            with self.hdfs(path_info) as hdfs, closing(
-                hdfs.open_input_stream(path_info.path)
-            ) as fd:
-                if mode == "rb":
-                    yield fd
-                else:
-                    yield io.TextIOWrapper(fd, encoding=encoding)
-        except OSError as e:
-            # Empty .errno and not specific enough error class in pyarrow,
-            # see https://issues.apache.org/jira/browse/ARROW-6248
-            if "file does not exist" in str(e):
-                raise FileNotFoundError(*e.args)
-            raise
-
-    def exists(self, path_info) -> bool:
-        assert not isinstance(path_info, list)
-        assert path_info.scheme == "hdfs"
-        with self.hdfs(path_info) as hdfs:
-            import pyarrow.fs
-
-            file_info = hdfs.get_file_info(path_info.path)
-            return file_info.type != pyarrow.fs.FileType.NotFound
-
-    def _walk(self, hdfs, root, topdown=True):
-        import posixpath
-
-        from pyarrow.fs import FileSelector, FileType
-
-        dirs = deque()
-        nondirs = deque()
-
-        selector = FileSelector(root)
-        for entry in hdfs.get_file_info(selector):
-            if entry.type == FileType.Directory:
-                dirs.append(entry.base_name)
-            else:
-                nondirs.append(entry.base_name)
-
-        if topdown:
-            yield root, dirs, nondirs
-
-        for dname in dirs:
-            # NOTE: posixpath.join() is slower
-            yield from self._walk(
-                hdfs, f"{root}{posixpath.sep}{dname}", topdown=topdown
-            )
-
-        if not topdown:
-            yield root, dirs, nondirs
-
-    def walk(self, top, topdown=True, onerror=None, **kwargs):
-        if not self.isdir(top):
-            return
-
-        with self.hdfs(top) as hdfs:
-            for root, dnames, fnames in self._walk(
-                hdfs, top.path, topdown=topdown
-            ):
-                yield top.replace(path=root), dnames, fnames
-
-    def walk_files(self, path_info, **kwargs):
-        for root, _, fnames in self.walk(path_info):
-            yield from (root / fname for fname in fnames)
-
-    def remove(self, path_info):
-        if path_info.scheme != "hdfs":
-            raise NotImplementedError
-
-        if self.exists(path_info):
-            logger.debug(f"Removing {path_info.path}")
-            with self.hdfs(path_info) as hdfs:
-                import pyarrow.fs
-
-                file_info = hdfs.get_file_info(path_info.path)
-                if file_info.type == pyarrow.fs.FileType.Directory:
-                    hdfs.delete_dir(path_info.path)
-                else:
-                    hdfs.delete_file(path_info.path)
-
-    def makedirs(self, path_info, **kwargs):
-        with self.hdfs(path_info) as hdfs:
-            # NOTE: fs.create_dir creates parents by default
-            hdfs.create_dir(path_info.path)
-
-    def copy(self, from_info, to_info, **_kwargs):
-        # NOTE: hdfs.copy_file is not supported yet in pyarrow
-        with self.hdfs(to_info) as hdfs:
-            # NOTE: this is how `hadoop fs -cp` works too: it copies through
-            # your local machine.
-            with closing(hdfs.open_input_stream(from_info.path)) as from_fobj:
-                tmp_info = to_info.parent / tmp_fname(to_info.name)
-                try:
-                    with closing(
-                        hdfs.open_output_stream(tmp_info.path)
-                    ) as tmp_fobj:
-                        shutil.copyfileobj(from_fobj, tmp_fobj)
-                    hdfs.move(tmp_info.path, to_info.path)
-                except Exception:
-                    self.remove(tmp_info)
-                    raise
-
-    def isfile(self, path_info):
-        with self.hdfs(path_info) as hdfs:
-            import pyarrow.fs
-
-            file_info = hdfs.get_file_info(path_info.path)
-            return file_info.type == pyarrow.fs.FileType.File
-
-    def isdir(self, path_info):
-        with self.hdfs(path_info) as hdfs:
-            import pyarrow.fs
-
-            file_info = hdfs.get_file_info(path_info.path)
-            return file_info.type == pyarrow.fs.FileType.Directory
-
-    def info(self, path_info):
-        with self.hdfs(path_info) as hdfs:
-            from pyarrow.fs import FileType
-
-            file_info = hdfs.get_file_info(path_info.path)
-            if file_info.type is FileType.Directory:
-                kind = "directory"
-            elif file_info.type is FileType.File:
-                kind = "file"
-            else:
-                raise FileNotFoundError(
-                    errno.ENOENT, os.strerror(errno.ENOENT), path_info
-                )
-
-            return {"size": file_info.size, "type": kind}
+        return HadoopFileSystem(**self.fs_args)

    def checksum(self, path_info):
-        return HashInfo(
-            "checksum",
-            _hadoop_fs_checksum(path_info),
-            size=self.getsize(path_info),
+        return self._checksum(path_info)
+
+    def _checksum(self, path_info, **kwargs):
+        # PyArrow doesn't natively support retrieving the
+        # checksum, so we have to use hadoop fs
+
+        result = self._run_command(
+            f"checksum {path_info.url}",
+            env=fix_env(os.environ),
+            user=path_info.user,
        )
+        if result is None:
+            return None

-    def upload_fobj(self, fobj, to_info, **kwargs):
-        with self.hdfs(to_info) as hdfs:
-            with hdfs.open_output_stream(to_info.path) as fdest:
-                shutil.copyfileobj(fobj, fdest, self.BLOCK_SIZE)
+        match = CHECKSUM_REGEX.match(result)
+        if match is None:
+            return None

-    def _upload(
-        self, from_file, to_info, name=None, no_progress_bar=False, **_kwargs
-    ):
-        with self.hdfs(to_info) as hdfs:
-            tmp_file = tmp_fname(to_info.path)
-            total = os.path.getsize(from_file)
-            with open(from_file, "rb") as fobj:
-                with Tqdm.wrapattr(
-                    fobj,
-                    "read",
-                    desc=name,
-                    total=total,
-                    disable=no_progress_bar,
-                ) as wrapped:
-                    with hdfs.open_output_stream(tmp_file) as sobj:
-                        shutil.copyfileobj(wrapped, sobj, self.BLOCK_SIZE)
-            hdfs.move(tmp_file, to_info.path)
+        return match.group("checksum")

-    def _download(
-        self, from_info, to_file, name=None, no_progress_bar=False, **_kwargs
-    ):
-        with self.hdfs(from_info) as hdfs:
-            file_info = hdfs.get_file_info(from_info.path)
-            total = file_info.size
-            with open(to_file, "wb+") as fobj:
-                with Tqdm.wrapattr(
-                    fobj,
-                    "write",
-                    desc=name,
-                    total=total,
-                    disable=no_progress_bar,
-                ) as wrapped:
-                    with hdfs.open_input_stream(from_info.path) as sobj:
-                        shutil.copyfileobj(sobj, wrapped, self.BLOCK_SIZE)
+    def _run_command(self, cmd, env=None, user=None):
+        cmd = "hadoop fs -" + cmd
+        if user:
+            cmd = f"HADOOP_USER_NAME={user} " + cmd
+
+        # NOTE: close_fds doesn't work with redirected stdin/stdout/stderr.
+        # See https://github.com/iterative/dvc/issues/1197.
+        close_fds = os.name != "nt"
+
+        executable = os.getenv("SHELL") if os.name != "nt" else None
+        p = subprocess.Popen(
+            cmd,
+            shell=True,
+            close_fds=close_fds,
+            executable=executable,
+            env=env or os.environ,
+            stdin=subprocess.PIPE,
+            stdout=subprocess.PIPE,
+            stderr=subprocess.PIPE,
+        )
+        out, err = p.communicate()
+
+        if p.returncode != 0:
+            raise subprocess.CalledProcessError(p.returncode, cmd, out, err)
+        else:
+            return out.decode("utf-8")
@@ -6,7 +6,7 @@ from dvc import prompt
 from dvc.path_info import HTTPURLInfo
 from dvc.scheme import Schemes

-from .fsspec_wrapper import CallbackMixin, FSSpecWrapper, NoDirectoriesMixin
+from .fsspec_wrapper import FSSpecWrapper, NoDirectoriesMixin


@wrap_with(threading.Lock())
@@ -32,7 +32,7 @@ def make_context(ssl_verify):


 # pylint: disable=abstract-method
-class HTTPFileSystem(CallbackMixin, NoDirectoriesMixin, FSSpecWrapper):
+class HTTPFileSystem(NoDirectoriesMixin, FSSpecWrapper):
    scheme = Schemes.HTTP
    PATH_CLS = HTTPURLInfo
    PARAM_CHECKSUM = "checksum"
@@ -87,6 +87,9 @@ class HTTPFileSystem(CallbackMixin, NoDirectoriesMixin, FSSpecWrapper):
                    ssl=make_context(config["ssl_verify"])
                )

+        # Allow reading proxy configurations from the environment.
+        client_kwargs["trust_env"] = True
+
        credentials["get_client"] = self.get_client
        self.upload_method = config.get("method", "POST")
        return credentials
@@ -99,6 +102,7 @@ class HTTPFileSystem(CallbackMixin, NoDirectoriesMixin, FSSpecWrapper):
            attempts=self.SESSION_RETRIES,
            factor=self.SESSION_BACKOFF_FACTOR,
            max_timeout=self.REQUEST_TIMEOUT,
+            exceptions=[aiohttp.ClientError],
        )

        # The default timeout for the aiohttp is 300 seconds
@@ -7,6 +7,7 @@ from dvc.system import System
 from dvc.utils import is_exec, tmp_fname
 from dvc.utils.fs import copy_fobj_to_file, copyfile, makedirs, move, remove

+from ..progress import DEFAULT_CALLBACK
 from .base import BaseFileSystem

 logger = logging.getLogger(__name__)
@@ -158,21 +159,15 @@ class LocalFileSystem(BaseFileSystem):
    def info(self, path_info):
        return self.fs.info(path_info)

-    def _upload(
-        self, from_file, to_info, name=None, no_progress_bar=False, **_kwargs
+    def put_file(
+        self, from_file, to_info, callback=DEFAULT_CALLBACK, **kwargs
    ):
        makedirs(to_info.parent, exist_ok=True)
-
        tmp_file = tmp_fname(to_info)
-        copyfile(
-            from_file, tmp_file, name=name, no_progress_bar=no_progress_bar
-        )
+        copyfile(from_file, tmp_file, callback=callback)
        os.replace(tmp_file, to_info)

-    @staticmethod
-    def _download(
-        from_info, to_file, name=None, no_progress_bar=False, **_kwargs
+    def get_file(
+        self, from_info, to_file, callback=DEFAULT_CALLBACK, **kwargs
    ):
-        copyfile(
-            from_info, to_file, no_progress_bar=no_progress_bar, name=name
-        )
+        copyfile(from_info, to_file, callback=callback)
@@ -7,13 +7,13 @@ from funcy import cached_property, wrap_prop
 from dvc.path_info import CloudURLInfo
 from dvc.scheme import Schemes

-from .fsspec_wrapper import CallbackMixin, ObjectFSWrapper
+from .fsspec_wrapper import ObjectFSWrapper

 logger = logging.getLogger(__name__)


 # pylint:disable=abstract-method
-class OSSFileSystem(CallbackMixin, ObjectFSWrapper):
+class OSSFileSystem(ObjectFSWrapper):
    scheme = Schemes.OSS
    PATH_CLS = CloudURLInfo
    REQUIRES = {"ossfs": "ossfs"}
@@ -9,6 +9,7 @@ from funcy import lfilter, wrap_with

 from dvc.path_info import PathInfo

+from ..progress import DEFAULT_CALLBACK
 from .base import BaseFileSystem
 from .dvc import DvcFileSystem

@@ -448,19 +449,21 @@ class RepoFileSystem(BaseFileSystem):  # pylint:disable=abstract-method
            for fname in files:
                yield PathInfo(root) / fname

-    def _download(self, from_info, to_file, **kwargs):
+    def get_file(
+        self, from_info, to_file, callback=DEFAULT_CALLBACK, **kwargs
+    ):
        fs, dvc_fs = self._get_fs_pair(from_info)
        try:
-            fs._download(  # pylint: disable=protected-access
-                from_info, to_file, **kwargs
+            fs.get_file(  # pylint: disable=protected-access
+                from_info, to_file, callback=callback, **kwargs
            )
            return
        except FileNotFoundError:
            if not dvc_fs:
                raise

-        dvc_fs._download(  # pylint: disable=protected-access
-            from_info, to_file, **kwargs
+        dvc_fs.get_file(  # pylint: disable=protected-access
+            from_info, to_file, callback=callback, **kwargs
        )

    def metadata(self, path):
@@ -6,7 +6,7 @@ from collections import defaultdict
 from funcy import cached_property, wrap_prop

 from dvc.path_info import CloudURLInfo
-from dvc.progress import Tqdm
+from dvc.progress import DEFAULT_CALLBACK
 from dvc.scheme import Schemes

 from .fsspec_wrapper import ObjectFSWrapper
@@ -99,6 +99,11 @@ class BaseS3FileSystem(ObjectFSWrapper):
        client["endpoint_url"] = config.get("endpointurl")
        client["verify"] = config.get("ssl_verify")

+        # timeout configuration
+        config_kwargs = login_info["config_kwargs"]
+        config_kwargs["read_timeout"] = config.get("read_timeout")
+        config_kwargs["connect_timeout"] = config.get("connect_timeout")
+
        # encryptions
        additional = login_info["s3_additional_kwargs"]
        additional["ServerSideEncryption"] = config.get("sse")
@@ -204,36 +209,23 @@ class S3FileSystem(BaseS3FileSystem):  # pylint:disable=abstract-method
        return bucket.Object(path_info.path)

    @_translate_exceptions
-    def _upload(
-        self, from_file, to_info, name=None, no_progress_bar=False, **pbar_args
+    def put_file(
+        self, from_file, to_info, callback=DEFAULT_CALLBACK, **kwargs
    ):
-        total = os.path.getsize(from_file)
-        with Tqdm(
-            disable=no_progress_bar,
-            total=total,
-            bytes=True,
-            desc=name,
-            **pbar_args,
-        ) as pbar:
-            obj = self._get_obj(to_info)
-            obj.upload_file(
-                from_file,
-                Callback=pbar.update,
-                ExtraArgs=self.fs_args.get("s3_additional_kwargs"),
-                Config=self._transfer_config,
-            )
+        callback.set_size(os.path.getsize(from_file))
+        obj = self._get_obj(to_info)
+        obj.upload_file(
+            from_file,
+            Callback=callback.relative_update,
+            ExtraArgs=self.fs_args.get("s3_additional_kwargs"),
+            Config=self._transfer_config,
+        )
        self.fs.invalidate_cache(self._with_bucket(to_info.parent))

    @_translate_exceptions
-    def _download(
-        self, from_info, to_file, name=None, no_progress_bar=False, **pbar_args
+    def get_file(
+        self, from_info, to_info, callback=DEFAULT_CALLBACK, **kwargs
    ):
        obj = self._get_obj(from_info)
-        with Tqdm(
-            disable=no_progress_bar,
-            total=obj.content_length,
-            bytes=True,
-            desc=name,
-            **pbar_args,
-        ) as pbar:
-            obj.download_file(to_file, Callback=pbar.update)
+        callback.set_size(obj.content_length)
+        obj.download_file(to_info, Callback=callback.relative_update)
@@ -8,7 +8,8 @@ from dvc import prompt
 from dvc.scheme import Schemes
 from dvc.utils.fs import as_atomic

-from .fsspec_wrapper import CallbackMixin, FSSpecWrapper
+from ..progress import DEFAULT_CALLBACK
+from .fsspec_wrapper import FSSpecWrapper

 _SSH_TIMEOUT = 60 * 30
 _SSH_CONFIG_FILE = os.path.expanduser(os.path.join("~", ".ssh", "config"))
@@ -26,7 +27,7 @@ def ask_password(host, user, port):


 # pylint:disable=abstract-method
-class SSHFileSystem(CallbackMixin, FSSpecWrapper):
+class SSHFileSystem(FSSpecWrapper):
    scheme = Schemes.SSH
    REQUIRES = {"sshfs": "sshfs"}

@@ -35,10 +36,8 @@ class SSHFileSystem(CallbackMixin, FSSpecWrapper):

    def _with_bucket(self, path):
        if isinstance(path, self.PATH_CLS):
-            path_str = path.path
-        else:
-            path_str = super()._with_bucket(path)
-        return os.path.normpath(path_str)
+            return path.path
+        return super()._with_bucket(path)

    def _prepare_credentials(self, **config):
        self.CAN_TRAVERSE = True
@@ -66,6 +65,11 @@ class SSHFileSystem(CallbackMixin, FSSpecWrapper):
            or self.DEFAULT_PORT
        )

+        if config.get("ask_password") and config.get("password") is None:
+            config["password"] = ask_password(
+                login_info["host"], login_info["username"], login_info["port"]
+            )
+
        login_info["password"] = config.get("password")
        login_info["passphrase"] = config.get("password")

@@ -100,11 +104,6 @@ class SSHFileSystem(CallbackMixin, FSSpecWrapper):
        login_info["agent_forwarding"] = config.get("agent_forwarding", True)
        login_info["proxy_command"] = user_ssh_config.get("ProxyCommand")

-        if config.get("ask_password") and login_info["password"] is None:
-            login_info["password"] = ask_password(
-                login_info["host"], login_info["username"], login_info["port"]
-            )
-
        # We are going to automatically add stuff to known_hosts
        # something like paramiko's AutoAddPolicy()
        login_info["known_hosts"] = None
@@ -124,6 +123,8 @@ class SSHFileSystem(CallbackMixin, FSSpecWrapper):
        with as_atomic(self, to_info) as tmp_file:
            super().upload_fobj(fobj, tmp_file, **kwargs)

-    def _upload(self, from_file, to_info, *args, **kwargs):
+    def put_file(
+        self, from_file, to_info, callback=DEFAULT_CALLBACK, **kwargs
+    ):
        with as_atomic(self, to_info) as tmp_file:
-            super()._upload(from_file, tmp_file, *args, **kwargs)
+            super().put_file(from_file, tmp_file, callback=callback, **kwargs)
@@ -84,7 +84,7 @@ class WebDAVFileSystem(FSSpecWrapper):  # pylint:disable=abstract-method
            return path.path[len(self.prefix) :].lstrip("/")
        return path

-    _with_bucket = translate_path_info
+    _with_bucket = translate_path_info  # type: ignore


 class WebDAVSFileSystem(WebDAVFileSystem):  # pylint:disable=abstract-method
@@ -1,51 +1,24 @@
-import logging
-import os
-import posixpath
-import shutil
 import threading
-from contextlib import contextmanager

 from funcy import cached_property, wrap_prop

-from dvc.hash_info import HashInfo
 from dvc.path_info import CloudURLInfo
-from dvc.progress import Tqdm
 from dvc.scheme import Schemes

-from .base import BaseFileSystem
-
-logger = logging.getLogger(__name__)
+# pylint:disable=abstract-method
+from .fsspec_wrapper import CallbackMixin, FSSpecWrapper


-def update_pbar(pbar, total):
-    """Update pbar to accept the two arguments passed by hdfs"""
-
-    def update(_, bytes_transfered):
-        if bytes_transfered == -1:
-            pbar.update_to(total)
-            return
-        pbar.update_to(bytes_transfered)
-
-    return update
-
-
-class WebHDFSFileSystem(BaseFileSystem):  # pylint:disable=abstract-method
+class WebHDFSFileSystem(CallbackMixin, FSSpecWrapper):
    scheme = Schemes.WEBHDFS
    PATH_CLS = CloudURLInfo
-    REQUIRES = {"hdfs": "hdfs"}
+    REQUIRES = {"fsspec": "fsspec"}
    PARAM_CHECKSUM = "checksum"
-    TRAVERSE_PREFIX_LEN = 2

-    def __init__(self, **config):
-        super().__init__(**config)
-
-        self.host = config["host"]
-        self.user = config.get("user")
-        self.port = config.get("port")
-
-        self.hdfscli_config = config.get("hdfscli_config")
-        self.token = config.get("webhdfs_token")
-        self.alias = config.get("webhdfs_alias")
+    def _with_bucket(self, path):
+        if isinstance(path, self.PATH_CLS):
+            return f"/{path.path.rstrip('/')}"
+        return path

    @staticmethod
    def _get_kwargs_from_urls(urlpath):
@@ -57,115 +30,20 @@ class WebHDFSFileSystem(BaseFileSystem):  # pylint:disable=abstract-method
            )
        )

+    def _prepare_credentials(self, **config):
+        if "webhdfs_token" in config:
+            config["token"] = config.pop("webhdfs_token")
+
+        return config
+
    @wrap_prop(threading.Lock())
    @cached_property
-    def hdfs_client(self):
-        import hdfs
+    def fs(self):
+        from fsspec.implementations.webhdfs import WebHDFS

-        logger.debug("HDFSConfig: %s", self.hdfscli_config)
-
-        try:
-            return hdfs.config.Config(self.hdfscli_config).get_client(
-                self.alias
-            )
-        except hdfs.util.HdfsError as exc:
-            exc_msg = str(exc)
-            errors = (
-                "No alias specified",
-                "Invalid configuration file",
-                f"Alias {self.alias} not found",
-            )
-            if not any(err in exc_msg for err in errors):
-                raise
-
-            http_url = f"http://{self.host}:{self.port}"
-            logger.debug("URL: %s", http_url)
-
-            if self.token is not None:
-                client = hdfs.TokenClient(http_url, token=self.token, root="/")
-            else:
-                client = hdfs.InsecureClient(
-                    http_url, user=self.user, root="/"
-                )
-
-        return client
-
-    @contextmanager
-    def open(self, path_info, mode="r", encoding=None, **kwargs):
-        assert mode in {"r", "rt", "rb"}
-
-        with self.hdfs_client.read(
-            path_info.path, encoding=encoding
-        ) as reader:
-            yield reader
-
-    def walk_files(self, path_info, **kwargs):
-        if not self.exists(path_info):
-            return
-
-        root = path_info.path
-        for path, _, fnames in self.hdfs_client.walk(root):
-            for fname in fnames:
-                yield path_info.replace(path=posixpath.join(path, fname))
-
-    def remove(self, path_info):
-        if path_info.scheme != self.scheme:
-            raise NotImplementedError
-
-        self.hdfs_client.delete(path_info.path)
-
-    def exists(self, path_info) -> bool:
-        assert not isinstance(path_info, list)
-        assert path_info.scheme == "webhdfs"
-
-        status = self.hdfs_client.status(path_info.path, strict=False)
-        return status is not None
-
-    def info(self, path_info):
-        st = self.hdfs_client.status(path_info.path)
-        return {"size": st["length"], "type": "file"}
+        return WebHDFS(**self.fs_args)

    def checksum(self, path_info):
-        return HashInfo(
-            "checksum",
-            self.hdfs_client.checksum(path_info.path)["bytes"],
-            size=self.hdfs_client.status(path_info.path)["length"],
-        )
-
-    def copy(self, from_info, to_info, **_kwargs):
-        with self.hdfs_client.read(from_info.path) as reader:
-            with self.hdfs_client.write(to_info.path) as writer:
-                shutil.copyfileobj(reader, writer)
-
-    def move(self, from_info, to_info):
-        self.hdfs_client.makedirs(to_info.parent.path)
-        self.hdfs_client.rename(from_info.path, to_info.path)
-
-    def upload_fobj(self, fobj, to_info, **kwargs):
-        with self.hdfs_client.write(to_info.path) as fdest:
-            shutil.copyfileobj(fobj, fdest)
-
-    def _upload(
-        self, from_file, to_info, name=None, no_progress_bar=False, **_kwargs
-    ):
-        total = os.path.getsize(from_file)
-        with Tqdm(
-            desc=name, total=total, disable=no_progress_bar, bytes=True
-        ) as pbar:
-            self.hdfs_client.upload(
-                to_info.path,
-                from_file,
-                overwrite=True,
-                progress=update_pbar(pbar, total),
-            )
-
-    def _download(
-        self, from_info, to_file, name=None, no_progress_bar=False, **_kwargs
-    ):
-        total = self.getsize(from_info)
-        with Tqdm(
-            desc=name, total=total, disable=no_progress_bar, bytes=True
-        ) as pbar:
-            self.hdfs_client.download(
-                from_info.path, to_file, progress=update_pbar(pbar, total)
-            )
+        path = self._with_bucket(path_info)
+        ukey = self.fs.ukey(path)
+        return ukey["bytes"]
@@ -7,13 +7,8 @@ HASH_DIR_SUFFIX = ".dir"

@dataclass
 class HashInfo:
-    PARAM_SIZE = "size"
-    PARAM_NFILES = "nfiles"
-
    name: Optional[str]
    value: Optional[str]
-    size: Optional[int] = field(default=None, compare=False)
-    nfiles: Optional[int] = field(default=None, compare=False)
    obj_name: Optional[str] = field(default=None, compare=False)

    def __bool__(self):
@@ -27,15 +22,11 @@ class HashInfo:

    @classmethod
    def from_dict(cls, d):
-        _d = d.copy() if d else {}
-        size = _d.pop(cls.PARAM_SIZE, None)
-        nfiles = _d.pop(cls.PARAM_NFILES, None)
-
-        if not _d:
+        if not d:
            return cls(None, None)

-        ((name, value),) = _d.items()
-        return cls(name, value, size=size, nfiles=nfiles)
+        ((name, value),) = d.items()
+        return cls(name, value)

    def to_dict(self):
        ret = OrderedDict()
@@ -43,10 +34,6 @@ class HashInfo:
            return ret

        ret[self.name] = self.value
-        if self.size is not None:
-            ret[self.PARAM_SIZE] = self.size
-        if self.nfiles is not None:
-            ret[self.PARAM_NFILES] = self.nfiles
        return ret

    @property
@@ -11,7 +11,6 @@ from dvc.fs.base import BaseFileSystem
 from dvc.path_info import PathInfo
 from dvc.pathspec_math import PatternInfo, merge_patterns
 from dvc.scheme import Schemes
-from dvc.system import System
 from dvc.types import AnyPath, List, Optional
 from dvc.utils import relpath
 from dvc.utils.collections import PathStringTrie
@@ -84,7 +83,7 @@ class DvcIgnorePatterns(DvcIgnore):
        else:
            return False

-        if not System.is_unix():
+        if os.name == "nt":
            path = normalize_file(path)
        return path

@@ -394,7 +393,7 @@ def init(path):
    if os.path.exists(dvcignore):
        return dvcignore

-    with open(dvcignore, "w") as fobj:
+    with open(dvcignore, "w", encoding="utf-8") as fobj:
        fobj.write(
            "# Add patterns of files dvc should ignore, which could improve\n"
            "# the performance. Learn more at\n"
@@ -6,6 +6,7 @@ import uuid

 import psutil

+from dvc import __version__
 from dvc.exceptions import DvcException, NotDvcRepoError
 from dvc.fs import FS_MAP, get_fs_cls, get_fs_config
 from dvc.repo import Repo
@@ -13,12 +14,6 @@ from dvc.scm.base import SCMError
 from dvc.system import System
 from dvc.utils import error_link
 from dvc.utils.pkg import PKG
-from dvc.version import __version__
-
-if PKG is None:
-    package = ""
-else:
-    package = f"({PKG})"

 try:
    import importlib.metadata as importlib_metadata
@@ -26,6 +21,9 @@ except ImportError:  # < 3.8
    import importlib_metadata  # type: ignore[no-redef]


+package = "" if PKG is None else f"({PKG})"
+
+
 def get_dvc_info():
    info = [
        f"DVC version: {__version__} {package}",
@@ -93,7 +91,7 @@ def _get_linktype_support_info(repo):

    fname = "." + str(uuid.uuid4())
    src = os.path.join(repo.odb.local.cache_dir, fname)
-    open(src, "w").close()
+    open(src, "w", encoding="utf-8").close()
    dst = os.path.join(repo.root_dir, fname)

    cache = []
@@ -136,11 +134,14 @@ def _get_supported_remotes():


 def get_fs_type(path):
-
-    partition = {
-        pathlib.Path(part.mountpoint): (part.fstype + " on " + part.device)
-        for part in psutil.disk_partitions(all=True)
-    }
+    partition = {}
+    for part in psutil.disk_partitions(all=True):
+        if part.fstype != "":
+            try:
+                mountpoint = pathlib.Path(part.mountpoint).resolve()
+                partition[mountpoint] = part.fstype + " on " + part.device
+            except PermissionError:
+                pass

    # need to follow the symlink: https://github.com/iterative/dvc/issues/5065
    path = pathlib.Path(path).resolve()
@@ -176,25 +176,14 @@ class HardlinkLock(flufl.lock.Lock, LockBase):
        except flufl.lock.TimeOutError:
            raise LockError(FAILED_TO_LOCK_MESSAGE)

-    def _set_claimfile(self, pid=None):
-        super()._set_claimfile(pid)
+    def _set_claimfile(self):
+        super()._set_claimfile()

        if self._tmp_dir is not None:
            # Under Windows file path length is limited so we hash it
            filename = hashlib.md5(self._claimfile.encode()).hexdigest()
            self._claimfile = os.path.join(self._tmp_dir, filename + ".lock")

-    # Fix for __del__ bug in flufl.lock [1] which is causing errors on
-    # Python shutdown [2].
-    # [1] https://gitlab.com/warsaw/flufl.lock/issues/7
-    # [2] https://github.com/iterative/dvc/issues/2573
-    def __del__(self):
-        try:
-            if self._owned:
-                self.finalize()
-        except ImportError:
-            pass
-

 def make_lock(lockfile, tmp_dir=None, friendly=False, hardlink_lock=False):
    cls = HardlinkLock if hardlink_lock else Lock
@@ -142,9 +142,22 @@ class LoggerHandler(logging.StreamHandler):
        super().handleError(record)
        raise LoggingException(record)

+    def emit_pretty_exception(self, exc, verbose: bool = False):
+        return exc.__pretty_exc__(verbose=verbose)
+
    def emit(self, record):
        """Write to Tqdm's stream so as to not break progress-bars"""
        try:
+            if record.exc_info:
+                _, exc, *_ = record.exc_info
+                if hasattr(exc, "__pretty_exc__"):
+                    try:
+                        self.emit_pretty_exception(exc, verbose=_is_verbose())
+                        if not _is_verbose():
+                            return
+                    except Exception:  # noqa, pylint: disable=broad-except
+                        pass
+
            msg = self.format(record)
            Tqdm.write(
                msg, file=self.stream, end=getattr(self, "terminator", "\n")
@@ -2,8 +2,10 @@ import logging
 import os
 from typing import (
    TYPE_CHECKING,
+    Any,
    Dict,
    Iterable,
+    Iterator,
    Mapping,
    Optional,
    Tuple,
@@ -181,7 +183,7 @@ class MachineManager:
        """Create and start the specified machine instance."""
        config, backend = self.get_config_and_backend(name)
        if "startup_script" in config:
-            with open(config["startup_script"]) as fobj:
+            with open(config["startup_script"], encoding="utf-8") as fobj:
                startup_script = fobj.read()
        else:
            startup_script = DEFAULT_STARTUP_SCRIPT
@@ -200,3 +202,12 @@ class MachineManager:
    def run_shell(self, name: Optional[str]):
        config, backend = self.get_config_and_backend(name)
        return backend.run_shell(**config)
+
+    def status(self, name: str) -> Iterator[Dict[Any, Any]]:
+        config, backend = self.get_config_and_backend(name)
+        return backend.instances(**config)
+
+    def rename(self, name: str, new: str):
+        """move configuration to a new location if the machine is running."""
+        config, backend = self.get_config_and_backend(name)
+        return backend.rename(new=new, **config)
@@ -10,7 +10,7 @@ if TYPE_CHECKING:

 class BaseMachineBackend(ABC):
    def __init__(self, tmp_dir: "StrPath", **kwargs):
-        raise NotImplementedError
+        self.tmp_dir = tmp_dir

    @abstractmethod
    def create(self, name: Optional[str] = None, **config):
@@ -48,3 +48,7 @@ class BaseMachineBackend(ABC):
    ) -> Iterator["SSHFileSystem"]:
        """Return an sshfs instance for the default directory on the
        specified machine."""
+
+    @abstractmethod
+    def rename(self, name: str, new: str, **config):
+        """Rename a machine instance."""
@@ -1,9 +1,11 @@
+import os
 from contextlib import contextmanager
+from functools import partialmethod
 from typing import TYPE_CHECKING, Iterator, Optional

-from tpi import TerraformProviderIterative, terraform
-
+from dvc.exceptions import DvcException
 from dvc.fs.ssh import SSHFileSystem
+from dvc.utils.fs import makedirs

 from .base import BaseMachineBackend

@@ -12,9 +14,42 @@ if TYPE_CHECKING:
    from dvc.types import StrPath


-class TerraformBackend(terraform.TerraformBackend, BaseMachineBackend):
+class TerraformBackend(BaseMachineBackend):
    def __init__(self, tmp_dir: "StrPath", **kwargs):
-        super().__init__(tmp_dir)
+        super().__init__(tmp_dir, **kwargs)
+        makedirs(tmp_dir, exist_ok=True)
+
+    @contextmanager
+    def make_tpi(self, name: str):
+        from tpi import TPIError
+        from tpi.terraform import TerraformBackend as TPIBackend
+
+        try:
+            working_dir = os.path.join(self.tmp_dir, name)
+            makedirs(working_dir, exist_ok=True)
+            yield TPIBackend(working_dir=working_dir)
+        except TPIError as exc:
+            raise DvcException("TPI operation failed") from exc
+
+    def _tpi_func(self, fname, name: Optional[str] = None, **config):
+        from tpi import TPIError
+
+        assert name
+        with self.make_tpi(name) as tpi:
+            func = getattr(tpi, fname)
+            try:
+                return func(name=name, **config)
+            except TPIError as exc:
+                raise DvcException(f"TPI {fname} failed") from exc
+
+    create = partialmethod(_tpi_func, "create")  # type: ignore[assignment]
+    destroy = partialmethod(_tpi_func, "destroy")  # type: ignore[assignment]
+    instances = partialmethod(
+        _tpi_func, "instances"
+    )  # type: ignore[assignment]
+    run_shell = partialmethod(
+        _tpi_func, "run_shell"
+    )  # type: ignore[assignment]

    def get_executor(
        self, name: Optional[str] = None, **config
@@ -25,7 +60,11 @@ class TerraformBackend(terraform.TerraformBackend, BaseMachineBackend):
    def get_sshfs(  # pylint: disable=unused-argument
        self, name: Optional[str] = None, **config
    ) -> Iterator["SSHFileSystem"]:
-        resource = self._default_resource(name)
+        from tpi import TerraformProviderIterative
+
+        assert name
+        with self.make_tpi(name) as tpi:
+            resource = tpi.default_resource(name)
        with TerraformProviderIterative.pemfile(resource) as pem:
            fs = SSHFileSystem(
                host=resource["instance_ip"],
@@ -33,3 +72,22 @@ class TerraformBackend(terraform.TerraformBackend, BaseMachineBackend):
                keyfile=pem,
            )
            yield fs
+
+    def rename(self, name: str, new: str, **config):
+        """rename a dvc machine instance to a new name"""
+        import shutil
+
+        mtype = "iterative_machine"
+
+        new_dir = os.path.join(self.tmp_dir, new)
+        old_dir = os.path.join(self.tmp_dir, name)
+        if os.path.exists(new_dir):
+            raise DvcException(f"rename failed: path {new_dir} already exists")
+
+        if not os.path.exists(old_dir):
+            return
+
+        with self.make_tpi(name) as tpi:
+            tpi.state_mv(f"{mtype}.{name}", f"{mtype}.{new}", **config)
+
+        shutil.move(old_dir, new_dir)
@@ -14,8 +14,8 @@ logger = logging.getLogger(__name__)

 def check(odb: "ObjectDB", obj: "HashFile", **kwargs):
    if isinstance(obj, Tree):
-        for _, entry in obj:
-            odb.check(entry.hash_info, **kwargs)
+        for _, _, oid in obj:
+            odb.check(oid, **kwargs)

    odb.check(obj.hash_info, **kwargs)

@@ -1,4 +1,5 @@
 import logging
+from itertools import chain

 from shortuuid import uuid

@@ -10,52 +11,18 @@ from dvc.exceptions import (
    DvcException,
 )
 from dvc.ignore import DvcIgnoreFilter
-from dvc.objects import check, load
 from dvc.objects.db.slow_link_detection import (  # type: ignore[attr-defined]
    slow_link_guard,
 )
-from dvc.objects.errors import ObjectFormatError
+from dvc.objects.diff import ROOT
+from dvc.objects.diff import diff as odiff
 from dvc.objects.stage import stage
 from dvc.types import Optional

 logger = logging.getLogger(__name__)


-def _changed(path_info, fs, obj, cache, state=None):
-    logger.trace("checking if '%s'('%s') has changed.", path_info, obj)
-
-    try:
-        check(cache, obj)
-    except (FileNotFoundError, ObjectFormatError):
-        logger.debug(
-            "cache for '%s'('%s') has changed.", path_info, obj.hash_info
-        )
-        return True
-
-    actual = state.get(path_info, fs) if state else None
-    if actual is None:
-        try:
-            actual = stage(
-                cache, path_info, fs, obj.hash_info.name, dry_run=True
-            )[1].hash_info
-        except FileNotFoundError:
-            logger.debug("'%s' doesn't exist.", path_info)
-            return True
-
-    if obj.hash_info != actual:
-        logger.debug(
-            "hash value '%s' for '%s' has changed (actual '%s').",
-            obj.hash_info,
-            actual,
-            path_info,
-        )
-        return True
-
-    logger.trace("'%s' hasn't changed.", path_info)
-    return False
-
-
-def _remove(path_info, fs, cache, force=False):
+def _remove(path_info, fs, in_cache, force=False):
    if not fs.exists(path_info):
        return

@@ -63,13 +30,7 @@ def _remove(path_info, fs, cache, force=False):
        fs.remove(path_info)
        return

-    current = stage(cache, path_info, fs, fs.PARAM_CHECKSUM, dry_run=True)[
-        1
-    ].hash_info
-    try:
-        obj = load(cache, current)
-        check(cache, obj)
-    except (FileNotFoundError, ObjectFormatError):
+    if not in_cache:
        msg = (
            f"file/directory '{path_info}' is going to be removed. "
            "Are you sure you want to proceed?"
@@ -98,7 +59,7 @@ def _verify_link(cache, path_info, link_type):

 def _do_link(cache, from_info, to_info, link_method):
    if cache.fs.exists(to_info):
-        raise DvcException(f"Link '{to_info}' already exists!")
+        cache.fs.remove(to_info)  # broken symlink

    link_method(from_info, to_info)

@@ -130,7 +91,7 @@ def _link(cache, from_info, to_info):
    try:
        _try_links(cache, from_info, to_info, cache.cache_types)
    except FileNotFoundError as exc:
-        raise CheckoutError([to_info]) from exc
+        raise CheckoutError([str(to_info)]) from exc


 def _cache_is_copy(cache, path_info):
@@ -160,7 +121,7 @@ def _cache_is_copy(cache, path_info):
 def _checkout_file(
    path_info,
    fs,
-    obj,
+    change,
    cache,
    force,
    progress_callback=None,
@@ -169,24 +130,24 @@ def _checkout_file(
 ):
    """The file is changed we need to checkout a new copy"""
    modified = False
-    cache_info = cache.hash_to_path_info(obj.hash_info.value)
-    if fs.exists(path_info):
-        if not relink and _changed(path_info, fs, obj, cache, state=state):
-            modified = True
-            _remove(path_info, fs, cache, force=force)
-            _link(cache, cache_info, path_info)
-        else:
+    cache_info = cache.hash_to_path_info(change.new.oid.value)
+    if change.old.oid:
+        if relink:
            if fs.iscopy(path_info) and _cache_is_copy(cache, path_info):
                cache.unprotect(path_info)
            else:
-                _remove(path_info, fs, cache, force=force)
+                _remove(path_info, fs, change.old.in_cache, force=force)
                _link(cache, cache_info, path_info)
+        else:
+            modified = True
+            _remove(path_info, fs, change.old.in_cache, force=force)
+            _link(cache, cache_info, path_info)
    else:
        _link(cache, cache_info, path_info)
        modified = True

    if state:
-        state.save(path_info, fs, obj.hash_info)
+        state.save(path_info, fs, change.new.oid)

    if progress_callback:
        progress_callback(str(path_info))
@@ -194,109 +155,83 @@ def _checkout_file(
    return modified


-def _remove_redundant_files(
-    path_info, fs, obj, cache, force, dvcignore: Optional[DvcIgnoreFilter]
-):
-    if dvcignore:
-        existing_files = set(dvcignore.walk_files(fs, path_info))
-    else:
-        existing_files = set(fs.walk_files(path_info))
-
-    needed_files = {path_info.joinpath(*key) for key, _ in obj}
-    redundant_files = existing_files - needed_files
-    for path in redundant_files:
-        _remove(path, fs, cache, force)
-
-    return bool(redundant_files)
-
-
-def _checkout_dir(
+def _diff(
    path_info,
    fs,
    obj,
    cache,
-    force,
-    progress_callback=None,
    relink=False,
    dvcignore: Optional[DvcIgnoreFilter] = None,
-    state=None,
 ):
-    modified = False
-    # Create dir separately so that dir is created
-    # even if there are no files in it
-    if not fs.exists(path_info):
-        modified = True
-        fs.makedirs(path_info)
-
-    logger.debug("Linking directory '%s'.", path_info)
-
-    failed = []
-    for entry_key, entry_obj in obj:
-        try:
-            entry_modified = _checkout_file(
-                path_info.joinpath(*entry_key),
-                fs,
-                entry_obj,
-                cache,
-                force,
-                progress_callback,
-                relink,
-                state=None,
-            )
-            if entry_modified:
-                modified = True
-        except CheckoutError as exc:
-            failed.extend(exc.target_infos)
-
-    modified = (
-        _remove_redundant_files(
-            path_info, fs, obj, cache, force, dvcignore=dvcignore
+    old = None
+    try:
+        _, _, old = stage(
+            cache,
+            path_info,
+            fs,
+            obj.hash_info.name if obj else cache.fs.PARAM_CHECKSUM,
+            dry_run=True,
+            dvcignore=dvcignore,
        )
-        or modified
-    )
+    except FileNotFoundError:
+        pass

-    if failed:
-        raise CheckoutError(failed)
+    diff = odiff(old, obj, cache)

-    if state:
-        state.save(path_info, fs, obj.hash_info)
+    if relink:
+        diff.modified.extend(diff.unchanged)

-    # relink is not modified, assume it as nochange
-    return modified and not relink
+    return diff


 def _checkout(
+    diff,
    path_info,
    fs,
-    obj,
    cache,
    force=False,
    progress_callback=None,
    relink=False,
-    dvcignore: Optional[DvcIgnoreFilter] = None,
    state=None,
 ):
-    if not obj.hash_info.isdir:
-        ret = _checkout_file(
-            path_info, fs, obj, cache, force, progress_callback, relink, state
-        )
-    else:
-        ret = _checkout_dir(
-            path_info,
-            fs,
-            obj,
-            cache,
-            force,
-            progress_callback,
-            relink,
-            dvcignore=dvcignore,
-            state=state,
-        )
+    if not diff:
+        return

-    if state:
-        state.save_link(path_info, fs)
+    for change in diff.deleted:
+        entry_path = (
+            path_info.joinpath(*change.old.key)
+            if change.old.key != ROOT
+            else path_info
+        )
+        _remove(entry_path, fs, change.old.in_cache, force=force)

-    return ret
+    failed = []
+    for change in chain(diff.added, diff.modified):
+        entry_path = (
+            path_info.joinpath(*change.new.key)
+            if change.new.key != ROOT
+            else path_info
+        )
+        if change.new.oid.isdir:
+            fs.makedirs(entry_path)
+            continue
+
+        try:
+            _checkout_file(
+                entry_path,
+                fs,
+                change,
+                cache,
+                force,
+                progress_callback,
+                relink,
+                state=state,
+            )
+        except CheckoutError as exc:
+            failed.extend(exc.target_infos)
+
+    if failed:
+        raise CheckoutError(failed)


 def checkout(
@@ -311,41 +246,54 @@ def checkout(
    dvcignore: Optional[DvcIgnoreFilter] = None,
    state=None,
 ):
+
    if path_info.scheme not in ["local", cache.fs.scheme]:
        raise NotImplementedError

-    failed = None
-    skip = False
+    diff = _diff(
+        path_info,
+        fs,
+        obj,
+        cache,
+        relink=relink,
+        dvcignore=dvcignore,
+    )
+
+    failed = []
    if not obj:
        if not quiet:
            logger.warning(
                "No file hash info found for '%s'. It won't be created.",
                path_info,
            )
-        _remove(path_info, fs, cache, force=force)
-        failed = path_info
-
-    elif not relink and not _changed(path_info, fs, obj, cache, state=state):
+        failed.append(str(path_info))
+    elif not diff:
        logger.trace("Data '%s' didn't change.", path_info)  # type: ignore
-        skip = True

-    if failed or skip:
+    try:
+        _checkout(
+            diff,
+            path_info,
+            fs,
+            cache,
+            force=force,
+            progress_callback=progress_callback,
+            relink=relink,
+            state=state,
+        )
+    except CheckoutError as exc:
+        failed.extend(exc.target_infos)
+
+    if diff and state:
+        state.save_link(path_info, fs)
+        if not failed:
+            state.save(path_info, fs, obj.hash_info)
+
+    if failed or not diff:
        if progress_callback and obj:
            progress_callback(str(path_info), len(obj))
        if failed:
-            raise CheckoutError([failed])
+            raise CheckoutError(failed)
        return

-    logger.debug("Checking out '%s' with cache '%s'.", path_info, obj)
-
-    return _checkout(
-        path_info,
-        fs,
-        obj,
-        cache,
-        force,
-        progress_callback,
-        relink,
-        dvcignore=dvcignore,
-        state=state,
-    )
+    return bool(diff) and not relink
@@ -97,7 +97,6 @@ class ObjectDB:
        hash_info: "HashInfo",
        move: bool = True,
        verify: Optional[bool] = None,
-        **kwargs,
    ):
        if self.read_only:
            raise ObjectDBPermissionError("Cannot add to read-only ODB")
@@ -121,10 +120,6 @@ class ObjectDB:
        except (ObjectFormatError, FileNotFoundError):
            pass

-        callback = kwargs.get("download_callback")
-        if callback:
-            callback(1)
-
    def hash_to_path_info(self, hash_) -> "DvcPath":
        return self.path_info / hash_[0:2] / hash_[2:]

@@ -0,0 +1,134 @@
+from dataclasses import dataclass, field
+from typing import TYPE_CHECKING, List, Optional, Tuple
+
+if TYPE_CHECKING:
+    from dvc.hash_info import HashInfo
+
+    from .file import HashFile
+
+ADD = "add"
+MODIFY = "modify"
+DELETE = "delete"
+UNCHANGED = "unchanged"
+
+
+@dataclass
+class TreeEntry:
+    in_cache: bool
+    key: Tuple[str]
+    oid: Optional["HashInfo"] = field(default=None)
+
+    def __bool__(self):
+        return bool(self.oid)
+
+    def __eq__(self, other):
+        if not isinstance(other, TreeEntry):
+            return False
+
+        if self.key != other.key:
+            return False
+
+        return self.oid == other.oid
+
+
+@dataclass
+class Change:
+    old: TreeEntry
+    new: TreeEntry
+
+    @property
+    def typ(self):
+        if not self.old and not self.new:
+            return UNCHANGED
+
+        if self.old and not self.new:
+            return DELETE
+
+        if not self.old and self.new:
+            return ADD
+
+        if self.old != self.new:
+            return MODIFY
+
+        return UNCHANGED
+
+    def __bool__(self):
+        return self.typ != UNCHANGED
+
+
+@dataclass
+class DiffResult:
+    added: List[Change] = field(default_factory=list, compare=True)
+    modified: List[Change] = field(default_factory=list, compare=True)
+    deleted: List[Change] = field(default_factory=list, compare=True)
+    unchanged: List[Change] = field(default_factory=list, compare=True)
+
+    def __bool__(self):
+        return bool(self.added or self.modified or self.deleted)
+
+
+ROOT = ("",)
+
+
+def diff(
+    old: Optional["HashFile"], new: Optional["HashFile"], cache
+) -> DiffResult:
+    from .tree import Tree
+
+    if old is None and new is None:
+        return DiffResult()
+
+    def _get_keys(obj):
+        if not obj:
+            return []
+        return [ROOT] + (
+            [key for key, _, _ in obj] if isinstance(obj, Tree) else []
+        )
+
+    old_keys = set(_get_keys(old))
+    new_keys = set(_get_keys(new))
+
+    def _get_oid(obj, key):
+        if not obj or key == ROOT:
+            return obj.hash_info if obj else None
+
+        entry_obj = obj.get(cache, key)
+        return entry_obj.hash_info if entry_obj else None
+
+    def _in_cache(oid, cache):
+        from .errors import ObjectFormatError
+
+        if not oid:
+            return False
+
+        try:
+            cache.check(oid)
+            return True
+        except (FileNotFoundError, ObjectFormatError):
+            return False
+
+    ret = DiffResult()
+    for key in old_keys | new_keys:
+        old_oid = _get_oid(old, key)
+        new_oid = _get_oid(new, key)
+
+        change = Change(
+            old=TreeEntry(_in_cache(old_oid, cache), key, old_oid),
+            new=TreeEntry(_in_cache(new_oid, cache), key, new_oid),
+        )
+
+        if change.typ == ADD:
+            ret.added.append(change)
+        elif change.typ == MODIFY:
+            ret.modified.append(change)
+        elif change.typ == DELETE:
+            ret.deleted.append(change)
+        else:
+            assert change.typ == UNCHANGED
+            if not change.new.in_cache and not (
+                change.new.oid and change.new.oid.isdir
+            ):
+                ret.modified.append(change)
+            else:
+                ret.unchanged.append(change)
+    return ret
@@ -28,10 +28,6 @@ class HashFile:
        self.hash_info = hash_info
        self.name = name

-    @property
-    def size(self):
-        return self.hash_info.size
-
    def __len__(self):
        return 1

@@ -74,7 +70,7 @@ class HashFile:
    def _check_hash(self, odb):
        from .stage import get_file_hash

-        actual = get_file_hash(
+        _, actual = get_file_hash(
            self.path_info, self.fs, self.hash_info.name, odb.state
        )

@@ -0,0 +1,32 @@
+from collections import OrderedDict
+from dataclasses import dataclass, field
+from typing import Optional
+
+
+@dataclass
+class Meta:
+    PARAM_SIZE = "size"
+    PARAM_NFILES = "nfiles"
+
+    size: Optional[int] = field(default=None)
+    nfiles: Optional[int] = field(default=None)
+
+    @classmethod
+    def from_dict(cls, d):
+        if not d:
+            return cls()
+
+        size = d.pop(cls.PARAM_SIZE, None)
+        nfiles = d.pop(cls.PARAM_NFILES, None)
+        return cls(size=size, nfiles=nfiles)
+
+    def to_dict(self):
+        ret = OrderedDict()
+
+        if self.size is not None:
+            ret[self.PARAM_SIZE] = self.size
+
+        if self.nfiles is not None:
+            ret[self.PARAM_NFILES] = self.nfiles
+
+        return ret
@@ -14,6 +14,7 @@ from dvc.utils import file_md5

 from .db.reference import ReferenceObjectDB
 from .file import HashFile
+from .meta import Meta

 if TYPE_CHECKING:
    from dvc.fs.base import BaseFileSystem
@@ -38,49 +39,48 @@ def _upload_file(path_info, fs, odb, upload_odb):
        upload_odb.fs.upload(stream, tmp_info, desc=path_info.name, total=size)

    odb.add(tmp_info, upload_odb.fs, stream.hash_info)
-    return path_info, odb.get(stream.hash_info)
+    meta = Meta(size=size)
+    return path_info, meta, odb.get(stream.hash_info)


 def _get_file_hash(path_info, fs, name):
    info = fs.info(path_info)
    if name in info:
        assert not info[name].endswith(".dir")
-        return HashInfo(name, info[name], size=info["size"])
+        hash_value = info[name]
+    elif hasattr(fs, name):
+        func = getattr(fs, name)
+        hash_value = func(path_info)
+    elif name == "md5":
+        hash_value = file_md5(path_info, fs)
+    else:
+        raise NotImplementedError

-    func = getattr(fs, name, None)
-    if func:
-        return func(path_info)
-
-    if name == "md5":
-        return HashInfo(
-            name, file_md5(path_info, fs), size=fs.getsize(path_info)
-        )
-
-    raise NotImplementedError
+    meta = Meta(size=info["size"])
+    hash_info = HashInfo(name, hash_value)
+    return meta, hash_info


 def get_file_hash(path_info, fs, name, state=None):
    if state:
-        hash_info = state.get(  # pylint: disable=assignment-from-none
+        meta, hash_info = state.get(  # pylint: disable=assignment-from-none
            path_info, fs
        )
        if hash_info:
-            return hash_info
+            return meta, hash_info

-    hash_info = _get_file_hash(path_info, fs, name)
+    meta, hash_info = _get_file_hash(path_info, fs, name)

    if state:
        assert ".dir" not in hash_info.value
        state.save(path_info, fs, hash_info)

-    return hash_info
+    return meta, hash_info


-def _get_file_obj(
-    path_info, fs, name, odb=None, upload_odb=None, dry_run=False
-):
+def _stage_file(path_info, fs, name, odb=None, upload_odb=None, dry_run=False):
    state = odb.state if odb else None
-    hash_info = get_file_hash(path_info, fs, name, state=state)
+    meta, hash_info = get_file_hash(path_info, fs, name, state=state)
    if upload_odb and not dry_run:
        assert odb and name == "md5"
        return _upload_file(path_info, fs, odb, upload_odb)
@@ -90,7 +90,8 @@ def _get_file_obj(
    else:
        odb.add(path_info, fs, hash_info, move=False)
        obj = odb.get(hash_info)
-    return path_info, obj
+
+    return path_info, meta, obj


 def _build_objects(
@@ -113,7 +114,7 @@ def _build_objects(
    ) as pbar:
        worker = pbar.wrap_fn(
            partial(
-                _get_file_obj,
+                _stage_file,
                fs=fs,
                name=name,
                **kwargs,
@@ -132,8 +133,9 @@ def _iter_objects(path_info, fs, name, **kwargs):
 def _build_tree(path_info, fs, name, **kwargs):
    from .tree import Tree

+    tree_meta = Meta(size=0, nfiles=0)
    tree = Tree(None, None, None)
-    for file_info, obj in _iter_objects(path_info, fs, name, **kwargs):
+    for file_info, meta, obj in _iter_objects(path_info, fs, name, **kwargs):
        if DvcIgnore.DVCIGNORE_FILE == file_info.name:
            raise DvcIgnoreInCollectedDirError(file_info.parent)

@@ -145,11 +147,15 @@ def _build_tree(path_info, fs, name, **kwargs):
        #
        # Yes, this is a BUG, as long as we permit "/" in
        # filenames on Windows and "\" on Unix
-        tree.add(file_info.relative_to(path_info).parts, obj)
-    return tree
+        tree.add(file_info.relative_to(path_info).parts, meta, obj.hash_info)
+
+        tree_meta.size += meta.size
+        tree_meta.nfiles += 1
+
+    return tree_meta, tree


-def _get_tree_obj(path_info, fs, fs_info, name, odb=None, **kwargs):
+def _stage_tree(path_info, fs, fs_info, name, odb=None, **kwargs):
    from .tree import Tree

    value = fs_info.get(name)
@@ -157,21 +163,15 @@ def _get_tree_obj(path_info, fs, fs_info, name, odb=None, **kwargs):
        hash_info = HashInfo(name, value)
        try:
            tree = Tree.load(odb, hash_info)
-            # NOTE: loaded entries are naive objects with hash_infos but no
-            # path_info. For staging trees, obj.path_info should be relative
-            # to the staging src `path_info` and src fs
-            for key, entry in tree:
-                entry.fs = fs
-                entry.path_info = path_info.joinpath(*key)
-            return tree
+            return Meta(nfiles=len(tree)), tree
        except FileNotFoundError:
            pass

-    tree = _build_tree(path_info, fs, name, odb=odb, **kwargs)
+    meta, tree = _build_tree(path_info, fs, name, odb=odb, **kwargs)
    state = odb.state if odb and odb.state else None
    hash_info = None
    if state:
-        hash_info = state.get(  # pylint: disable=assignment-from-none
+        _, hash_info = state.get(  # pylint: disable=assignment-from-none
            path_info, fs
        )
    tree.digest(hash_info=hash_info)
@@ -183,7 +183,7 @@ def _get_tree_obj(path_info, fs, fs_info, name, odb=None, **kwargs):
        tree.fs.remove(tree.path_info)
    tree.fs = raw.fs
    tree.path_info = raw.path_info
-    return tree
+    return meta, tree


 _url_cache: Dict[str, str] = {}
@@ -225,7 +225,7 @@ def _load_from_state(odb, staging, path_info, fs, name):
    from .tree import Tree

    state = odb.state
-    hash_info = state.get(path_info, fs)
+    meta, hash_info = state.get(path_info, fs)
    if hash_info:
        for odb_ in (odb, staging):
            if odb_.exists(hash_info):
@@ -233,16 +233,9 @@ def _load_from_state(odb, staging, path_info, fs, name):
                    obj = load(odb_, hash_info)
                    check(odb_, obj, check_hash=False)
                    if isinstance(obj, Tree):
-                        obj.hash_info.nfiles = len(obj)
-                        for key, entry in obj:
-                            entry.fs = fs
-                            entry.path_info = path_info.joinpath(*key)
-                    else:
-                        obj.fs = fs
-                        obj.path_info = path_info
+                        meta.nfiles = len(obj)
                    assert obj.hash_info.name == name
-                    obj.hash_info.size = hash_info.size
-                    return odb_, obj
+                    return odb_, meta, obj
                except (ObjectFormatError, FileNotFoundError):
                    pass
    raise FileNotFoundError
@@ -257,7 +250,7 @@ def _stage_external_tree_info(odb, tree, name):

    odb.add(tree.path_info, tree.fs, tree.hash_info)
    raw = odb.get(tree.hash_info)
-    hash_info = get_file_hash(raw.path_info, raw.fs, name, state=odb.state)
+    _, hash_info = get_file_hash(raw.path_info, raw.fs, name, state=odb.state)
    tree.path_info = raw.path_info
    tree.fs = raw.fs
    tree.hash_info.name = hash_info.name
@@ -275,7 +268,7 @@ def stage(
    upload: bool = False,
    dry_run: bool = False,
    **kwargs,
-) -> Tuple["ObjectDB", "HashFile"]:
+) -> Tuple["ObjectDB", "Meta", "HashFile"]:
    """Stage (prepare) objects from the given path for addition to an ODB.

    Returns at tuple of (staging_odb, object) where addition to the ODB can
@@ -300,7 +293,7 @@ def stage(
            pass

    if details["type"] == "directory":
-        obj = _get_tree_obj(
+        meta, obj = _stage_tree(
            path_info,
            fs,
            details,
@@ -314,7 +307,7 @@ def stage(
        if name != "md5":
            obj = _stage_external_tree_info(odb, obj, name)
    else:
-        _, obj = _get_file_obj(
+        _, meta, obj = _stage_file(
            path_info,
            fs,
            name,
@@ -326,4 +319,4 @@ def stage(
    if odb and odb.state and obj.hash_info:
        odb.state.save(path_info, fs, obj.hash_info)

-    return staging, obj
+    return staging, meta, obj
@@ -56,7 +56,7 @@ def _indexed_dir_hashes(odb, index, dir_objs, name, cache_odb):
                tree = Tree.load(cache_odb, HashInfo(name, dir_hash))
            except FileNotFoundError:
                continue
-        file_hashes = [entry.hash_info.value for _, entry in tree]
+        file_hashes = [oid.value for _, _, oid in tree]
        if dir_hash not in index:
            logger.debug(
                "Indexing new .dir '%s' with '%s' nested files",
@@ -102,9 +102,9 @@ def status(
                tree = None
            else:
                tree = Tree.load(cache_odb, hash_info)
-                for _, entry in tree:
-                    assert entry.hash_info and entry.hash_info.value
-                    hash_infos[entry.hash_info.value] = entry.hash_info
+                for _, _, oid in tree:
+                    assert oid and oid.value
+                    hash_infos[oid.value] = oid
            if index:
                dir_objs[hash_info.value] = tree
        hash_infos[hash_info.value] = hash_info
@@ -74,7 +74,7 @@ def _do_transfer(
        dir_obj = find_tree_by_obj_id([cache_odb, src], dir_hash)
        assert dir_obj

-        entry_ids = {entry.hash_info for _, entry in dir_obj}
+        entry_ids = {oid for _, _, oid in dir_obj}
        bound_file_ids = all_file_ids & entry_ids
        all_file_ids -= entry_ids

@@ -117,7 +117,7 @@ def _do_transfer(
    # index successfully pushed dirs
    if dest_index:
        for dir_obj in succeeded_dir_objs:
-            file_hashes = {entry.hash_info.value for _, entry in dir_obj}
+            file_hashes = {oid.value for _, _, oid in dir_obj}
            logger.debug(
                "Indexing pushed dir '%s' with '%s' nested files",
                dir_obj.hash_info,
@@ -12,6 +12,8 @@ from .stage import get_file_hash
 if TYPE_CHECKING:
    from dvc.hash_info import HashInfo

+    from .meta import Meta
+
 logger = logging.getLogger(__name__)


@@ -20,7 +22,7 @@ class Tree(HashFile):

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
-        self._dict: Dict[Tuple[str], "HashFile"] = {}
+        self._dict: Dict[Tuple[str], Tuple["Meta", "HashInfo"]] = {}

    @cached_property
    def trie(self):
@@ -28,9 +30,9 @@ class Tree(HashFile):

        return Trie(self._dict)

-    def add(self, key, obj):
+    def add(self, key: Tuple[str], meta: "Meta", oid: "HashInfo"):
        self.__dict__.pop("trie", None)
-        self._dict[key] = obj
+        self._dict[key] = (meta, oid)

    def digest(self, hash_info: Optional["HashInfo"] = None):
        from dvc.fs.memory import MemoryFileSystem
@@ -46,20 +48,17 @@ class Tree(HashFile):
        if hash_info:
            self.hash_info = hash_info
        else:
-            self.hash_info = get_file_hash(path_info, memfs, "md5")
+            _, self.hash_info = get_file_hash(path_info, memfs, "md5")
            assert self.hash_info.value
            self.hash_info.value += ".dir"
-        try:
-            self.hash_info.size = sum(obj.size for _, obj in self)
-        except TypeError:
-            self.hash_info.size = None
-        self.hash_info.nfiles = len(self)

    def __len__(self):
        return len(self._dict)

    def __iter__(self):
-        yield from self._dict.items()
+        yield from (
+            (key, value[0], value[1]) for key, value in self._dict.items()
+        )

    def as_dict(self):
        return self._dict.copy()
@@ -73,10 +72,10 @@ class Tree(HashFile):
                {
                    # NOTE: not using hash_info.to_dict() because we don't want
                    # size/nfiles fields at this point.
-                    obj.hash_info.name: obj.hash_info.value,
+                    oid.name: oid.value,
                    self.PARAM_RELPATH: posixpath.sep.join(parts),
                }
-                for parts, obj in self._dict.items()  # noqa: B301
+                for parts, _, oid in self  # noqa: B301
            ),
            key=itemgetter(self.PARAM_RELPATH),
        )
@@ -94,8 +93,7 @@ class Tree(HashFile):
            relpath = entry.pop(cls.PARAM_RELPATH)
            parts = tuple(relpath.split(posixpath.sep))
            hash_info = HashInfo.from_dict(entry)
-            obj = HashFile(None, None, hash_info)
-            tree.add(parts, obj)
+            tree.add(parts, None, hash_info)
        return tree

    @classmethod
@@ -118,8 +116,6 @@ class Tree(HashFile):
        tree = cls.from_list(raw)
        tree.path_info = obj.path_info
        tree.fs = obj.fs
-        for _, entry_obj in tree:
-            entry_obj.fs = obj.fs
        tree.hash_info = hash_info

        return tree
@@ -135,37 +131,37 @@ class Tree(HashFile):
        """
        tree = Tree(self.path_info, self.fs, self.hash_info)
        try:
-            for key, obj in self.trie.items(prefix):
-                tree.add(key, obj)
+            for key, (meta, oid) in self.trie.items(prefix):
+                tree.add(key, meta, oid)
        except KeyError:
            pass
        return tree

-    def get(self, prefix: Tuple[str]) -> Optional[HashFile]:
+    def get(self, odb, prefix: Tuple[str]) -> Optional[HashFile]:
        """Return object at the specified prefix in this tree.

        Returns None if no object exists at the specified prefix.
        """
-        obj = self._dict.get(prefix)
-        if obj:
-            return obj
+        _, oid = self._dict.get(prefix) or (None, None)
+        if oid:
+            return odb.get(oid)

        tree = Tree(None, None, None)
        depth = len(prefix)
        try:
-            for key, obj in self.trie.items(prefix):
-                tree.add(key[depth:], obj)
+            for key, (meta, entry_oid) in self.trie.items(prefix):
+                tree.add(key[depth:], meta, entry_oid)
        except KeyError:
            return None
        tree.digest()
        return tree


-def _get_dir_size(odb, tree):
+def du(odb, tree):
    try:
        return sum(
-            odb.fs.getsize(odb.hash_to_path_info(obj.hash_info.value))
-            for _, obj in tree
+            odb.fs.getsize(odb.hash_to_path_info(oid.value))
+            for _, _, oid in tree
        )
    except FileNotFoundError:
        return None
@@ -226,11 +222,8 @@ def merge(odb, ancestor_info, our_info, their_info):
    merged_dict = _merge(ancestor.as_dict(), our.as_dict(), their.as_dict())

    merged = Tree(None, None, None)
-    for key, hi in merged_dict.items():
-        merged.add(key, hi)
+    for key, (meta, oid) in merged_dict.items():
+        merged.add(key, meta, oid)
    merged.digest()

-    odb.add(merged.path_info, merged.fs, merged.hash_info)
-    hash_info = merged.hash_info
-    hash_info.size = _get_dir_size(odb, merged)
-    return hash_info
+    return merged
@@ -1,7 +1,6 @@
 import logging
 import os
 from collections import defaultdict
-from copy import copy
 from typing import TYPE_CHECKING, Dict, Optional, Set, Type
 from urllib.parse import urlparse

@@ -9,7 +8,6 @@ from funcy import collecting, project
 from voluptuous import And, Any, Coerce, Length, Lower, Required, SetTo

 from dvc import objects, prompt
-from dvc.checkout import checkout
 from dvc.exceptions import (
    CheckoutError,
    CollectCacheError,
@@ -17,6 +15,7 @@ from dvc.exceptions import (
    MergeError,
    RemoteCacheRequiredError,
 )
+from dvc.objects.checkout import checkout

 from .fs import get_cloud_fs
 from .fs.hdfs import HDFSFileSystem
@@ -26,6 +25,7 @@ from .hash_info import HashInfo
 from .istextfile import istextfile
 from .objects import Tree
 from .objects.errors import ObjectFormatError
+from .objects.meta import Meta
 from .objects.stage import stage as ostage
 from .objects.transfer import transfer as otransfer
 from .scheme import Schemes
@@ -316,6 +316,7 @@ class Output:
        # By resolved path, which contains actual location,
        # should be absolute and don't contain remote:// refs.
        self.stage = stage
+        self.meta = Meta.from_dict(info)
        self.hash_info = HashInfo.from_dict(info)
        self.use_cache = False if self.IS_DEPENDENCY else cache
        self.metric = False if self.IS_DEPENDENCY else metric
@@ -415,7 +416,7 @@ class Output:
        else:
            odb = self.repo.odb.local
            name = self.fs.PARAM_CHECKSUM
-        _, obj = ostage(
+        _, _, obj = ostage(
            odb,
            self.path_info,
            self.fs,
@@ -537,7 +538,15 @@ class Output:
            self.verify_metric()

        if not self.use_cache:
-            self.hash_info = self.get_hash()
+            _, self.meta, obj = ostage(
+                self.repo.odb.local,
+                self.path_info,
+                self.fs,
+                self.fs.PARAM_CHECKSUM,
+                dvcignore=self.dvcignore,
+                dry_run=True,
+            )
+            self.hash_info = obj.hash_info
            if not self.IS_DEPENDENCY:
                logger.debug(
                    "Output '%s' doesn't use cache. Skipping saving.", self
@@ -550,7 +559,7 @@ class Output:
            logger.debug("Output '%s' didn't change. Skipping saving.", self)
            return

-        _, self.obj = ostage(
+        _, self.meta, self.obj = ostage(
            self.odb,
            self.path_info,
            self.fs,
@@ -579,7 +588,7 @@ class Output:
            if granular:
                obj = self._commit_granular_dir(filter_info)
            else:
-                staging, obj = ostage(
+                staging, _, obj = ostage(
                    self.odb,
                    filter_info or self.path_info,
                    self.fs,
@@ -606,7 +615,7 @@ class Output:

    def _commit_granular_dir(self, filter_info):
        prefix = filter_info.relative_to(self.path_info).parts
-        staging, save_obj = ostage(
+        staging, _, save_obj = ostage(
            self.odb,
            self.path_info,
            self.fs,
@@ -614,18 +623,18 @@ class Output:
            dvcignore=self.dvcignore,
        )
        save_obj = save_obj.filter(prefix)
-        checkout_obj = save_obj.get(prefix)
+        checkout_obj = save_obj.get(self.odb, prefix)
        otransfer(
            staging,
            self.odb,
-            {save_obj.hash_info} | {entry.hash_info for _, entry in save_obj},
+            {save_obj.hash_info} | {oid for _, _, oid in save_obj},
            shallow=True,
            move=True,
        )
        return checkout_obj

    def dumpd(self):
-        ret = copy(self.hash_info.to_dict())
+        ret = {**self.hash_info.to_dict(), **self.meta.to_dict()}

        if self.is_in_repo:
            path = self.path_info.relpath(self.stage.wdir).as_posix()
@@ -709,7 +718,7 @@ class Output:

        if filter_info and filter_info != self.path_info:
            prefix = filter_info.relative_to(self.path_info).parts
-            obj = obj.get(prefix)
+            obj = obj.get(self.odb, prefix)

        return obj

@@ -803,7 +812,7 @@ class Output:

        upload = not (update and from_fs.isdir(from_info))
        jobs = jobs or min((from_fs.jobs, odb.fs.jobs))
-        staging, obj = ostage(
+        staging, self.meta, obj = ostage(
            odb,
            from_info,
            from_fs,
@@ -832,7 +841,7 @@ class Output:
            return 1

        if not filter_info or filter_info == self.path_info:
-            return self.hash_info.nfiles or 0
+            return self.meta.nfiles or 0

        obj = self.get_obj(filter_info=filter_info)
        return len(obj) if obj else 0
@@ -849,8 +858,9 @@ class Output:
        try:
            objects.check(self.odb, obj)
        except FileNotFoundError:
-            remote = self.repo.cloud.get_remote_odb(self.remote)
-            self.repo.cloud.pull([obj.hash_info], odb=remote, **kwargs)
+            if self.remote:
+                kwargs["remote"] = self.remote
+            self.repo.cloud.pull([obj.hash_info], **kwargs)

        if self.obj:
            return self.obj
@@ -945,9 +955,9 @@ class Output:
        obj.hash_info.obj_name = name
        oids = {obj.hash_info}
        if isinstance(obj, Tree):
-            for key, entry_obj in obj:
-                entry_obj.hash_info.obj_name = self.fs.sep.join([name, *key])
-                oids.add(entry_obj.hash_info)
+            for key, _, oid in obj:
+                oid.obj_name = self.fs.sep.join([name, *key])
+                oids.add(oid)
        return oids

    def get_used_external(
@@ -980,8 +990,8 @@ class Output:

        ignored = [
            self.fs.PARAM_CHECKSUM,
-            HashInfo.PARAM_SIZE,
-            HashInfo.PARAM_NFILES,
+            Meta.PARAM_SIZE,
+            Meta.PARAM_NFILES,
        ]

        for opt in ignored:
@@ -999,7 +1009,7 @@ class Output:
            )

    def merge(self, ancestor, other):
-        from dvc.objects.tree import merge
+        from dvc.objects.tree import du, merge

        assert other

@@ -1012,9 +1022,16 @@ class Output:
        self._check_can_merge(self)
        self._check_can_merge(other)

-        self.hash_info = merge(
+        merged = merge(
            self.odb, ancestor_info, self.hash_info, other.hash_info
        )
+        self.odb.add(merged.path_info, merged.fs, merged.hash_info)
+
+        self.hash_info = merged.hash_info
+        self.meta = Meta(
+            size=du(self.odb, merged),
+            nfiles=len(merged),
+        )

    @property
    def fspath(self):
@@ -1039,8 +1056,8 @@ ARTIFACT_SCHEMA = {
    Output.PARAM_PLOT: bool,
    Output.PARAM_PERSIST: bool,
    Output.PARAM_CHECKPOINT: bool,
-    HashInfo.PARAM_SIZE: int,
-    HashInfo.PARAM_NFILES: int,
+    Meta.PARAM_SIZE: int,
+    Meta.PARAM_NFILES: int,
    Output.PARAM_ISEXEC: bool,
 }

@@ -1,5 +1,4 @@
 """Manages progress bars for DVC repo."""
-
 import logging
 import sys
 from threading import RLock
@@ -137,8 +136,8 @@ class Tqdm(tqdm):

        return wrapped

-    def as_callback(self, fs, path_info):
-        return FsspecCallback(fs, path_info, self)
+    def as_callback(self):
+        return FsspecCallback(self)

    def close(self):
        self.postfix["info"] = ""
@@ -168,23 +167,46 @@ class Tqdm(tqdm):


 class FsspecCallback(fsspec.Callback):
-    def __init__(self, fs, path_info, progress_bar):
-        self.fs = fs
-        self.path_info = path_info
+    def __init__(self, progress_bar):
        self.progress_bar = progress_bar
        super().__init__()

    def set_size(self, size):
-        """``set_size()`` is an API that might be called with ``None`` if the
-        information is not already present on the caller. In that case, we'll
-        retrieve the size from an ``info()`` call."""
-        if size is None:
-            size = self.fs.info(self.path_info)["size"]
-        self.progress_bar.total = size
-        self.progress_bar.refresh()
+        if size is not None:
+            self.progress_bar.total = size
+            self.progress_bar.refresh()
+            super().set_size(size)

    def relative_update(self, inc=1):
        self.progress_bar.update(inc)
+        super().relative_update(inc)

    def absolute_update(self, value):
        self.progress_bar.update_to(value)
+        super().absolute_update(value)
+
+    @staticmethod
+    def wrap_fn(cb, fn):
+        def wrapped(*args, **kwargs):
+            res = fn(*args, **kwargs)
+            cb.relative_update()
+            return res
+
+        return wrapped
+
+
+def tdqm_or_callback_wrapped(
+    fobj, method, total, callback=None, **pbar_kwargs
+):
+    if callback:
+        from funcy import nullcontext
+        from tqdm.utils import CallbackIOWrapper
+
+        callback.set_size(total)
+        wrapper = CallbackIOWrapper(callback.relative_update, fobj, method)
+        return nullcontext(wrapper)
+
+    return Tqdm.wrapattr(fobj, method, total=total, bytes=True, **pbar_kwargs)
+
+
+DEFAULT_CALLBACK = fsspec.callbacks.NoOpCallback()
@@ -89,7 +89,7 @@ def write(

    page_html = None
    if template_path:
-        with open(template_path) as fobj:
+        with open(template_path, encoding="utf-8") as fobj:
            page_html = fobj.read()

    document = HTML(page_html, refresh_seconds=refresh_seconds)
@@ -102,6 +102,6 @@ def write(

    index = Path(os.path.join(path, "index.html"))

-    with open(index, "w") as fd:
+    with open(index, "w", encoding="utf-8") as fd:
        fd.write(document.embed())
    return index
@@ -30,7 +30,6 @@ class ImageRenderer(Renderer):
        img_path = os.path.join(
            static, f"{revision}_{filename.replace(os.sep, '_')}"
        )
-        rel_img_path = relpath(img_path, page_dir_path)
        with open(img_path, "wb") as fd:
            fd.write(image_data)
        return """
@@ -38,7 +37,7 @@ class ImageRenderer(Renderer):
            <p>{title}</p>
            <img src="{src}">
        </div>""".format(
-            title=revision, src=rel_img_path
+            title=revision, src=(relpath(img_path, page_dir_path))
        )

    def _convert(self, path: "StrPath"):
@@ -1,48 +1,28 @@
 import os.path
-from typing import Dict, List, Set
+from typing import Dict, List
+
+import dpath.util


-def get_files(data: Dict) -> Set:
+def get_files(data: Dict) -> List:
    files = set()
    for rev in data.keys():
        for file in data[rev].get("data", {}).keys():
            files.add(file)
-    return files
+    sorted_files = sorted(files)
+    return sorted_files


 def group_by_filename(plots_data: Dict) -> List[Dict]:
-    # TODO use dpath.util.search once
-    #  https://github.com/dpath-maintainers/dpath-python/issues/147 is released
-    #  now cannot search when errors are present in data
    files = get_files(plots_data)
    grouped = []
-
    for file in files:
-        tmp: Dict = {}
-        for revision, revision_data in plots_data.items():
-            if file in revision_data.get("data", {}):
-                if "data" not in tmp:
-                    tmp[revision] = {"data": {}}
-                tmp[revision]["data"].update(
-                    {file: revision_data["data"][file]}
-                )
-        grouped.append(tmp)
-
+        grouped.append(dpath.util.search(plots_data, ["*", "*", file]))
    return grouped


 def find_vega(repo, plots_data, target):
-    # TODO same as group_by_filename
-    grouped = group_by_filename(plots_data)
-    found = None
-    for plot_group in grouped:
-        files = get_files(plot_group)
-        assert len(files) == 1
-        file = files.pop()
-        if file == target:
-            found = plot_group
-            break
-
+    found = dpath.util.search(plots_data, ["*", "*", target])
    from dvc.render.vega import VegaRenderer

    if found and VegaRenderer.matches(found):
@@ -28,7 +28,7 @@ class PlotDataStructureError(DvcException):
    def __init__(self):
        super().__init__(
            "Plot data extraction failed. Please see "
-            "https://man.dvc.org/plot for supported data formats."
+            "https://man.dvc.org/plots for supported data formats."
        )


@@ -147,7 +147,7 @@ class VegaRenderer(Renderer):
    def get_vega(self) -> Optional[str]:
        props = self._squash_props()

-        template = self.templates.load(props.get("template") or "default")
+        template = self.templates.load(props.get("template", None))

        if not props.get("x") and template.has_anchor("x"):
            props["append_index"] = True
@@ -120,6 +120,34 @@ class Repo:

        return root_dir, dvc_dir, tmp_dir

+    def _get_database_dir(self, db_name):
+        # NOTE: by default, store SQLite-based remote indexes and state's
+        # `links` and `md5s` caches in the repository itself to avoid any
+        # possible state corruption in 'shared cache dir' scenario, but allow
+        # user to override this through config when, say, the repository is
+        # located on a mounted volume — see
+        # https://github.com/iterative/dvc/issues/4420
+        base_db_dir = self.config.get(db_name, {}).get("dir", None)
+        if not base_db_dir:
+            return self.tmp_dir
+
+        import hashlib
+
+        from dvc.utils.fs import makedirs
+
+        root_dir_hash = hashlib.sha224(
+            self.root_dir.encode("utf-8")
+        ).hexdigest()
+
+        db_dir = os.path.join(
+            base_db_dir,
+            self.DVC_DIR,
+            f"{os.path.basename(self.root_dir)}-{root_dir_hash[0:7]}",
+        )
+
+        makedirs(db_dir, exist_ok=True)
+        return db_dir
+
    def __init__(
        self,
        root_dir=None,
@@ -135,7 +163,6 @@ class Repo:
        from dvc.data_cloud import DataCloud
        from dvc.fs.local import LocalFileSystem
        from dvc.lock import LockNoop, make_lock
-        from dvc.machine import MachineManager
        from dvc.objects.db import ODBManager
        from dvc.repo.live import Live
        from dvc.repo.metrics import Metrics
@@ -183,10 +210,8 @@ class Repo:
                friendly=True,
            )

-            # NOTE: storing state and link_state in the repository itself to
-            # avoid any possible state corruption in 'shared cache dir'
-            # scenario.
-            self.state = State(self.root_dir, self.tmp_dir, self.dvcignore)
+            state_db_dir = self._get_database_dir("state")
+            self.state = State(self.root_dir, state_db_dir, self.dvcignore)
            self.odb = ODBManager(self)

            self.stage_cache = StageCache(self)
@@ -198,14 +223,6 @@ class Repo:
        self.params = Params(self)
        self.live = Live(self)

-        if self.tmp_dir and (
-            self.config["feature"].get("machine", False)
-            or env2bool("DVC_TEST")
-        ):
-            self.machine = MachineManager(self)
-        else:
-            self.machine = None
-
        self.stage_collection_error_handler: Optional[
            Callable[[str, Exception], None]
        ] = None
@@ -272,6 +289,17 @@ class Repo:

        return Experiments(self)

+    @cached_property
+    def machine(self):
+        from dvc.machine import MachineManager
+
+        if self.tmp_dir and (
+            self.config["feature"].get("machine", False)
+            or env2bool("DVC_TEST")
+        ):
+            return MachineManager(self)
+        return None
+
    @property
    def fs(self) -> "BaseFileSystem":
        return self._fs
@@ -452,6 +480,10 @@ class Repo:

        return RepoFileSystem(self, subrepos=self.subrepos, **self._fs_conf)

+    @cached_property
+    def index_db_dir(self):
+        return self._get_database_dir("index")
+
    @contextmanager
    def open_by_relpath(self, path, remote=None, mode="r", encoding=None):
        """Opens a specified resource as a file descriptor"""
@@ -137,7 +137,7 @@ def _output_paths(repo, targets):
            )

            if on_working_fs:
-                _, obj = ostage(
+                _, _, obj = ostage(
                    repo.odb.local,
                    output.path_info,
                    repo.odb.local.fs,
@@ -164,13 +164,13 @@ def _output_paths(repo, targets):


 def _dir_output_paths(path_info, obj, targets=None):
-    for key, entry_obj in obj:
+    for key, _, oid in obj:
        fname = path_info.joinpath(*key)
        if targets is None or any(
            fname.isin_or_eq(target) for target in targets
        ):
            # pylint: disable=no-member
-            yield str(fname), entry_obj.hash_info.value
+            yield str(fname), oid.value


 def _filter_missing(repo_fs, paths):
@@ -10,6 +10,7 @@ from typing import Dict, Iterable, Mapping, Optional

 from funcy import cached_property, first

+from dvc.dependency.param import MissingParamsError
 from dvc.env import DVCLIVE_RESUME
 from dvc.exceptions import DvcException
 from dvc.path_info import PathInfo
@@ -350,9 +351,19 @@ class Experiments:
        )
        self.scm.add(self.args_file)

+    def _format_new_params_msg(self, new_params, config_path):
+        """Format an error message for when new parameters are identified"""
+        new_param_count = len(new_params)
+        pluralise = "s are" if new_param_count > 1 else " is"
+        param_list = ", ".join(new_params)
+        return (
+            f"{new_param_count} parameter{pluralise} missing "
+            f"from '{config_path}': {param_list}"
+        )
+
    def _update_params(self, params: dict):
        """Update experiment params files with the specified values."""
-        from dvc.utils.collections import merge_params
+        from dvc.utils.collections import NewParamsFound, merge_params
        from dvc.utils.serialize import MODIFIERS

        logger.debug("Using experiment params '%s'", params)
@@ -362,7 +373,11 @@ class Experiments:
            suffix = path.suffix.lower()
            modify_data = MODIFIERS[suffix]
            with modify_data(path, fs=self.repo.fs) as data:
-                merge_params(data, params[params_fname])
+                try:
+                    merge_params(data, params[params_fname], allow_new=False)
+                except NewParamsFound as e:
+                    msg = self._format_new_params_msg(e.new_params, path)
+                    raise MissingParamsError(msg)

        # Force params file changes to be staged in git
        # Otherwise in certain situations the changes to params file may be
@@ -490,7 +490,7 @@ class BaseExecutor(ABC):
                push_cache=push_cache,
                run_cache=run_cache,
            )
-        except BaseException as exc:
+        except BaseException as exc:  # pylint: disable=broad-except
            logger.warning(
                "Something went wrong while auto pushing experiment "
                f"to the remote '{git_remote}': {exc}"
@@ -64,7 +64,7 @@ class TempDirExecutor(BaseLocalExecutor):
    def _config(self, cache_dir):
        local_config = os.path.join(self.dvc_dir, "config.local")
        logger.debug("Writing experiments local config '%s'", local_config)
-        with open(local_config, "w") as fobj:
+        with open(local_config, "w", encoding="utf-8") as fobj:
            fobj.write(f"[cache]\n    dir = {cache_dir}")

    def cleanup(self):
@@ -0,0 +1,193 @@
+import os
+from typing import TYPE_CHECKING, Dict, Iterable
+
+from funcy import compact, lremove, post_processing
+from rich.prompt import Prompt
+
+from dvc.types import OptStr
+
+if TYPE_CHECKING:
+    from dvc.repo import Repo
+    from dvc.dvcfile import DVCFile
+    from dvc.stage import Stage
+
+from dvc.ui import ui
+
+PROMPTS = {
+    "cmd": "[b]Command[/b] to execute",
+    "code": "Path to a [b]code[/b] file/directory",
+    "data": "Path to a [b]data[/b] file/directory",
+    "models": "Path to a [b]model[/b] file/directory",
+    "params": "Path to a [b]parameters[/b] file",
+    "metrics": "Path to a [b]metrics[/b] file",
+    "plots": "Path to a [b]plots[/b] file/directory",
+    "live": "Path to log [b]dvclive[/b] outputs",
+}
+
+
+class RequiredPrompt(Prompt):
+    def process_response(self, value: str):
+        from rich.prompt import InvalidResponse
+
+        ret = super().process_response(value)
+        if not ret:
+            raise InvalidResponse(
+                "[prompt.invalid]Response required. Please try again."
+            )
+        return ret
+
+    @classmethod
+    def get_input(cls, *args, **kwargs) -> str:
+        try:
+            return super().get_input(*args, **kwargs)
+        except (KeyboardInterrupt, EOFError):
+            ui.error_write()
+            raise
+
+    def render_default(self, default):
+        from rich.text import Text
+
+        return Text(f"{default!s}", "green")
+
+
+class SkippablePrompt(RequiredPrompt):
+    skip_value: str = "n"
+
+    def process_response(self, value: str):
+        ret = super().process_response(value)
+        return None if ret == self.skip_value else ret
+
+    def make_prompt(self, default):
+        prompt = self.prompt.copy()
+        prompt.end = ""
+
+        prompt.append(" [")
+        if (
+            default is not ...
+            and self.show_default
+            and isinstance(default, (str, self.response_type))
+        ):
+            _default = self.render_default(default)
+            prompt.append(_default)
+            prompt.append(", ")
+
+        prompt.append(f"{self.skip_value} to skip", style="italic")
+        prompt.append("]")
+        prompt.append(self.prompt_suffix)
+        return prompt
+
+
+@post_processing(dict)
+def _prompts(keys: Iterable[str], defaults: Dict[str, OptStr]):
+    for key in keys:
+        if key == "cmd":
+            prompt_cls = RequiredPrompt
+        else:
+            prompt_cls = SkippablePrompt
+        kwargs = {"default": defaults[key]} if key in defaults else {}
+        prompt = PROMPTS.get(key)
+        value = prompt_cls.ask(prompt, console=ui.error_console, **kwargs)
+        yield key, value
+
+
+def init_interactive(
+    defaults: Dict[str, str],
+    provided: Iterable[str],
+    show_heading: bool = False,
+    live: bool = False,
+) -> Dict[str, str]:
+    primary = lremove(provided, ["cmd", "code", "data", "models", "params"])
+    secondary = lremove(provided, ["live"] if live else ["metrics", "plots"])
+
+    if not (primary or secondary):
+        return {}
+
+    message = (
+        "This command will guide you to set up your first stage in "
+        "[green]dvc.yaml[/green].\n"
+    )
+    if show_heading:
+        ui.error_write(message, styled=True)
+
+    return compact(
+        {
+            **_prompts(primary, defaults),
+            **_prompts(secondary, defaults),
+        }
+    )
+
+
+def _check_stage_exists(
+    dvcfile: "DVCFile", name: str, force: bool = False
+) -> None:
+    if not force and dvcfile.exists() and name in dvcfile.stages:
+        from dvc.stage.exceptions import DuplicateStageName
+
+        hint = "Use '--force' to overwrite."
+        raise DuplicateStageName(
+            f"Stage '{name}' already exists in 'dvc.yaml'. {hint}"
+        )
+
+
+def init(
+    repo: "Repo",
+    name: str = None,
+    type: str = "default",  # pylint: disable=redefined-builtin
+    defaults: Dict[str, str] = None,
+    overrides: Dict[str, str] = None,
+    interactive: bool = False,
+    force: bool = False,
+) -> "Stage":
+    from dvc.dvcfile import make_dvcfile
+
+    dvcfile = make_dvcfile(repo, "dvc.yaml")
+    name = name or type
+
+    _check_stage_exists(dvcfile, name, force=force)
+
+    defaults = defaults or {}
+    overrides = overrides or {}
+
+    with_live = type == "live"
+    if interactive:
+        defaults = init_interactive(
+            defaults=defaults or {},
+            show_heading=not dvcfile.exists(),
+            live=with_live,
+            provided=overrides.keys(),
+        )
+    else:
+        if with_live:
+            # suppress `metrics`/`params` if live is selected, unless
+            # it is also provided via overrides/cli.
+            # This makes output to be a checkpoint as well.
+            defaults.pop("metrics")
+            defaults.pop("params")
+        else:
+            defaults.pop("live")  # suppress live otherwise
+
+    context: Dict[str, str] = {**defaults, **overrides}
+    assert "cmd" in context
+
+    params_kv = []
+    if context.get("params"):
+        from dvc.utils.serialize import LOADERS
+
+        path = context["params"]
+        assert isinstance(path, str)
+        _, ext = os.path.splitext(path)
+        params_kv = [{path: list(LOADERS[ext](path))}]
+
+    checkpoint_out = bool(context.get("live"))
+    models = context.get("models")
+    return repo.stage.add(
+        name=name,
+        cmd=context["cmd"],
+        deps=compact([context.get("code"), context.get("data")]),
+        params=params_kv,
+        metrics_no_cache=compact([context.get("metrics")]),
+        plots_no_cache=compact([context.get("plots")]),
+        live=context.get("live"),
+        force=force,
+        **{"checkpoints" if checkpoint_out else "outs": compact([models])},
+    )
@@ -3,7 +3,7 @@ import io
 import logging
 import os
 from collections import OrderedDict
-from typing import TYPE_CHECKING, Callable, Dict, List, Optional
+from typing import TYPE_CHECKING, Callable, Dict, Generator, List, Optional

 from funcy import cached_property, first, project

@@ -20,6 +20,7 @@ from dvc.utils.serialize import LOADERS
 if TYPE_CHECKING:
    from dvc.output import Output
    from dvc.repo import Repo
+    from dvc.types import DvcPath

 logger = logging.getLogger(__name__)

@@ -47,10 +48,10 @@ class Plots:
        recursive: bool = False,
        onerror: Optional[Callable] = None,
        props: Optional[Dict] = None,
-    ) -> Dict[str, Dict]:
+    ) -> Generator[Dict, None, None]:
        """Collects all props and data for plots.

-        Returns a structure like:
+        Generator yielding a structure like:
            {rev: {plots.csv: {
                props: {x: ..., "header": ..., ...},
                data: "unstructured data (as stored for given extension)",
@@ -59,30 +60,20 @@ class Plots:
        from dvc.utils.collections import ensure_list

        targets = ensure_list(targets)
-        data: Dict[str, Dict] = {}
        for rev in self.repo.brancher(revs=revs):
            # .brancher() adds unwanted workspace
            if revs is not None and rev not in revs:
                continue
            rev = rev or "workspace"
-            data[rev] = self._collect_from_revision(
-                revision=rev,
-                targets=targets,
-                recursive=recursive,
-                onerror=onerror,
-                props=props,
-            )
-
-        errored = errored_revisions(data)
-        if errored:
-            from dvc.ui import ui
-
-            ui.error_write(
-                "DVC failed to load some plots for following revisions: "
-                f"'{', '.join(errored)}'."
-            )
-
-        return data
+            yield {
+                rev: self._collect_from_revision(
+                    revision=rev,
+                    targets=targets,
+                    recursive=recursive,
+                    onerror=onerror,
+                    props=props,
+                )
+            }

    @error_handler
    def _collect_from_revision(
@@ -135,9 +126,22 @@ class Plots:
        if onerror is None:
            onerror = onerror_collect

-        return self.collect(
+        data: Dict[str, Dict] = {}
+        for rev_data in self.collect(
            targets, revs, recursive, onerror=onerror, props=props
-        )
+        ):
+            data.update(rev_data)
+
+        errored = errored_revisions(data)
+        if errored:
+            from dvc.ui import ui
+
+            ui.error_write(
+                "DVC failed to load some plots for following revisions: "
+                f"'{', '.join(errored)}'."
+            )
+
+        return data

    def diff(self, *args, **kwargs):
        from .diff import diff
@@ -161,7 +165,7 @@ class Plots:
        props = props or {}
        template = props.get("template")
        if template:
-            self.templates.get_template(template)
+            self.templates.load(template)

        (out,) = self.repo.find_outs_by_path(path)
        if not out.plot and unset is not None:
@@ -201,7 +205,7 @@ def _collect_plots(
    targets: List[str] = None,
    rev: str = None,
    recursive: bool = False,
-) -> Dict[str, Dict]:
+) -> Dict["DvcPath", Dict]:
    from dvc.repo.collect import collect

    plots, path_infos = collect(
@@ -1,15 +1,23 @@
 import json
 import os
-from typing import Any, Dict, Optional
+from typing import TYPE_CHECKING, Iterable, Optional
+
+try:
+    import importlib_resources
+except ImportError:
+    import importlib.resources as importlib_resources  # type: ignore[no-redef]

 from funcy import cached_property

 from dvc.exceptions import DvcException

+if TYPE_CHECKING:
+    from dvc.types import StrPath
+

 class TemplateNotFoundError(DvcException):
-    def __init__(self, path):
-        super().__init__(f"Template '{path}' not found.")
+    def __init__(self, name):
+        super().__init__(f"Template '{name}' not found.")


 class BadTemplateError(DvcException):
@@ -29,25 +37,9 @@ class Template:
    EXTENSION = ".json"
    ANCHOR = "<DVC_METRIC_{}>"

-    DEFAULT_CONTENT: Optional[Dict[str, Any]] = None
-    DEFAULT_NAME: Optional[str] = None
-
-    def __init__(self, content=None, name=None):
-        if content:
-            self.content = content
-        else:
-            self.content = (
-                json.dumps(
-                    self.DEFAULT_CONTENT,
-                    indent=self.INDENT,
-                    separators=self.SEPARATORS,
-                )
-                + "\n"
-            )
-
-        self.name = name or self.DEFAULT_NAME
-        assert self.content and self.name
-        self.filename = self.name + self.EXTENSION
+    def __init__(self, content, name):
+        self.content = content
+        self.name = name

    def render(self, data, props=None):
        props = props or {}
@@ -55,7 +47,7 @@ class Template:
        if self._anchor_str("data") not in self.content:
            anchor = self.anchor("data")
            raise BadTemplateError(
-                f"Template '{self.filename}' is not using '{anchor}' anchor"
+                f"Template '{self.name}' is not using '{anchor}' anchor"
            )

        if props.get("x"):
@@ -106,466 +98,86 @@ class Template:
            raise NoFieldInDataError(field)


-class DefaultTemplate(Template):
-    DEFAULT_NAME = "default"
-
-    DEFAULT_CONTENT = {
-        "$schema": "https://vega.github.io/schema/vega-lite/v4.json",
-        "data": {"values": Template.anchor("data")},
-        "title": Template.anchor("title"),
-        "width": 300,
-        "height": 300,
-        "mark": {"type": "line"},
-        "encoding": {
-            "x": {
-                "field": Template.anchor("x"),
-                "type": "quantitative",
-                "title": Template.anchor("x_label"),
-            },
-            "y": {
-                "field": Template.anchor("y"),
-                "type": "quantitative",
-                "title": Template.anchor("y_label"),
-                "scale": {"zero": False},
-            },
-            "color": {"field": "rev", "type": "nominal"},
-        },
-    }
-
-
-class ConfusionTemplate(Template):
-    DEFAULT_NAME = "confusion"
-    DEFAULT_CONTENT = {
-        "$schema": "https://vega.github.io/schema/vega-lite/v4.json",
-        "data": {"values": Template.anchor("data")},
-        "title": Template.anchor("title"),
-        "facet": {"field": "rev", "type": "nominal"},
-        "spec": {
-            "transform": [
-                {
-                    "aggregate": [{"op": "count", "as": "xy_count"}],
-                    "groupby": [Template.anchor("y"), Template.anchor("x")],
-                },
-                {
-                    "impute": "xy_count",
-                    "groupby": ["rev", Template.anchor("y")],
-                    "key": Template.anchor("x"),
-                    "value": 0,
-                },
-                {
-                    "impute": "xy_count",
-                    "groupby": ["rev", Template.anchor("x")],
-                    "key": Template.anchor("y"),
-                    "value": 0,
-                },
-                {
-                    "joinaggregate": [
-                        {"op": "max", "field": "xy_count", "as": "max_count"}
-                    ],
-                    "groupby": [],
-                },
-                {
-                    "calculate": "datum.xy_count / datum.max_count",
-                    "as": "percent_of_max",
-                },
-            ],
-            "encoding": {
-                "x": {
-                    "field": Template.anchor("x"),
-                    "type": "nominal",
-                    "sort": "ascending",
-                    "title": Template.anchor("x_label"),
-                },
-                "y": {
-                    "field": Template.anchor("y"),
-                    "type": "nominal",
-                    "sort": "ascending",
-                    "title": Template.anchor("y_label"),
-                },
-            },
-            "layer": [
-                {
-                    "mark": "rect",
-                    "width": 300,
-                    "height": 300,
-                    "encoding": {
-                        "color": {
-                            "field": "xy_count",
-                            "type": "quantitative",
-                            "title": "",
-                            "scale": {"domainMin": 0, "nice": True},
-                        }
-                    },
-                },
-                {
-                    "mark": "text",
-                    "encoding": {
-                        "text": {"field": "xy_count", "type": "quantitative"},
-                        "color": {
-                            "condition": {
-                                "test": "datum.percent_of_max > 0.5",
-                                "value": "white",
-                            },
-                            "value": "black",
-                        },
-                    },
-                },
-            ],
-        },
-    }
-
-
-class NormalizedConfusionTemplate(Template):
-    DEFAULT_NAME = "confusion_normalized"
-    DEFAULT_CONTENT = {
-        "$schema": "https://vega.github.io/schema/vega-lite/v4.json",
-        "data": {"values": Template.anchor("data")},
-        "title": Template.anchor("title"),
-        "facet": {"field": "rev", "type": "nominal"},
-        "spec": {
-            "transform": [
-                {
-                    "aggregate": [{"op": "count", "as": "xy_count"}],
-                    "groupby": [Template.anchor("y"), Template.anchor("x")],
-                },
-                {
-                    "impute": "xy_count",
-                    "groupby": ["rev", Template.anchor("y")],
-                    "key": Template.anchor("x"),
-                    "value": 0,
-                },
-                {
-                    "impute": "xy_count",
-                    "groupby": ["rev", Template.anchor("x")],
-                    "key": Template.anchor("y"),
-                    "value": 0,
-                },
-                {
-                    "joinaggregate": [
-                        {"op": "sum", "field": "xy_count", "as": "sum_y"}
-                    ],
-                    "groupby": [Template.anchor("y")],
-                },
-                {
-                    "calculate": "datum.xy_count / datum.sum_y",
-                    "as": "percent_of_y",
-                },
-            ],
-            "encoding": {
-                "x": {
-                    "field": Template.anchor("x"),
-                    "type": "nominal",
-                    "sort": "ascending",
-                    "title": Template.anchor("x_label"),
-                },
-                "y": {
-                    "field": Template.anchor("y"),
-                    "type": "nominal",
-                    "sort": "ascending",
-                    "title": Template.anchor("y_label"),
-                },
-            },
-            "layer": [
-                {
-                    "mark": "rect",
-                    "width": 300,
-                    "height": 300,
-                    "encoding": {
-                        "color": {
-                            "field": "percent_of_y",
-                            "type": "quantitative",
-                            "title": "",
-                            "scale": {"domain": [0, 1]},
-                        }
-                    },
-                },
-                {
-                    "mark": "text",
-                    "encoding": {
-                        "text": {
-                            "field": "percent_of_y",
-                            "type": "quantitative",
-                            "format": ".2f",
-                        },
-                        "color": {
-                            "condition": {
-                                "test": "datum.percent_of_y > 0.5",
-                                "value": "white",
-                            },
-                            "value": "black",
-                        },
-                    },
-                },
-            ],
-        },
-    }
-
-
-class ScatterTemplate(Template):
-    DEFAULT_NAME = "scatter"
-
-    DEFAULT_CONTENT = {
-        "$schema": "https://vega.github.io/schema/vega-lite/v4.json",
-        "data": {"values": Template.anchor("data")},
-        "title": Template.anchor("title"),
-        "width": 300,
-        "height": 300,
-        "layer": [
-            {
-                "encoding": {
-                    "x": {
-                        "field": Template.anchor("x"),
-                        "type": "quantitative",
-                        "title": Template.anchor("x_label"),
-                    },
-                    "y": {
-                        "field": Template.anchor("y"),
-                        "type": "quantitative",
-                        "title": Template.anchor("y_label"),
-                        "scale": {"zero": False},
-                    },
-                    "color": {"field": "rev", "type": "nominal"},
-                },
-                "layer": [
-                    {"mark": "point"},
-                    {
-                        "selection": {
-                            "label": {
-                                "type": "single",
-                                "nearest": True,
-                                "on": "mouseover",
-                                "encodings": ["x"],
-                                "empty": "none",
-                                "clear": "mouseout",
-                            }
-                        },
-                        "mark": "point",
-                        "encoding": {
-                            "opacity": {
-                                "condition": {
-                                    "selection": "label",
-                                    "value": 1,
-                                },
-                                "value": 0,
-                            }
-                        },
-                    },
-                ],
-            },
-            {
-                "transform": [{"filter": {"selection": "label"}}],
-                "layer": [
-                    {
-                        "encoding": {
-                            "text": {
-                                "type": "quantitative",
-                                "field": Template.anchor("y"),
-                            },
-                            "x": {
-                                "field": Template.anchor("x"),
-                                "type": "quantitative",
-                            },
-                            "y": {
-                                "field": Template.anchor("y"),
-                                "type": "quantitative",
-                            },
-                        },
-                        "layer": [
-                            {
-                                "mark": {
-                                    "type": "text",
-                                    "align": "left",
-                                    "dx": 5,
-                                    "dy": -5,
-                                },
-                                "encoding": {
-                                    "color": {
-                                        "type": "nominal",
-                                        "field": "rev",
-                                    }
-                                },
-                            }
-                        ],
-                    }
-                ],
-            },
-        ],
-    }
-
-
-class SmoothLinearTemplate(Template):
-    DEFAULT_NAME = "smooth"
-
-    DEFAULT_CONTENT = {
-        "$schema": "https://vega.github.io/schema/vega-lite/v4.json",
-        "data": {"values": Template.anchor("data")},
-        "title": Template.anchor("title"),
-        "mark": {"type": "line"},
-        "encoding": {
-            "x": {
-                "field": Template.anchor("x"),
-                "type": "quantitative",
-                "title": Template.anchor("x_label"),
-            },
-            "y": {
-                "field": Template.anchor("y"),
-                "type": "quantitative",
-                "title": Template.anchor("y_label"),
-                "scale": {"zero": False},
-            },
-            "color": {"field": "rev", "type": "nominal"},
-        },
-        "transform": [
-            {
-                "loess": Template.anchor("y"),
-                "on": Template.anchor("x"),
-                "groupby": ["rev"],
-                "bandwidth": 0.3,
-            }
-        ],
-    }
-
-
-class LinearTemplate(Template):
-    DEFAULT_NAME = "linear"
-
-    DEFAULT_CONTENT = {
-        "$schema": "https://vega.github.io/schema/vega-lite/v4.json",
-        "data": {"values": Template.anchor("data")},
-        "title": Template.anchor("title"),
-        "width": 300,
-        "height": 300,
-        "layer": [
-            {
-                "encoding": {
-                    "x": {
-                        "field": Template.anchor("x"),
-                        "type": "quantitative",
-                        "title": Template.anchor("x_label"),
-                    },
-                    "y": {
-                        "field": Template.anchor("y"),
-                        "type": "quantitative",
-                        "title": Template.anchor("y_label"),
-                        "scale": {"zero": False},
-                    },
-                    "color": {"field": "rev", "type": "nominal"},
-                },
-                "layer": [
-                    {"mark": "line"},
-                    {
-                        "selection": {
-                            "label": {
-                                "type": "single",
-                                "nearest": True,
-                                "on": "mouseover",
-                                "encodings": ["x"],
-                                "empty": "none",
-                                "clear": "mouseout",
-                            }
-                        },
-                        "mark": "point",
-                        "encoding": {
-                            "opacity": {
-                                "condition": {
-                                    "selection": "label",
-                                    "value": 1,
-                                },
-                                "value": 0,
-                            }
-                        },
-                    },
-                ],
-            },
-            {
-                "transform": [{"filter": {"selection": "label"}}],
-                "layer": [
-                    {
-                        "mark": {"type": "rule", "color": "gray"},
-                        "encoding": {
-                            "x": {
-                                "field": Template.anchor("x"),
-                                "type": "quantitative",
-                            }
-                        },
-                    },
-                    {
-                        "encoding": {
-                            "text": {
-                                "type": "quantitative",
-                                "field": Template.anchor("y"),
-                            },
-                            "x": {
-                                "field": Template.anchor("x"),
-                                "type": "quantitative",
-                            },
-                            "y": {
-                                "field": Template.anchor("y"),
-                                "type": "quantitative",
-                            },
-                        },
-                        "layer": [
-                            {
-                                "mark": {
-                                    "type": "text",
-                                    "align": "left",
-                                    "dx": 5,
-                                    "dy": -5,
-                                },
-                                "encoding": {
-                                    "color": {
-                                        "type": "nominal",
-                                        "field": "rev",
-                                    }
-                                },
-                            }
-                        ],
-                    },
-                ],
-            },
-        ],
-    }
-
-
 class PlotTemplates:
    TEMPLATES_DIR = "plots"
-    TEMPLATES = [
-        DefaultTemplate,
-        LinearTemplate,
-        ConfusionTemplate,
-        NormalizedConfusionTemplate,
-        ScatterTemplate,
-        SmoothLinearTemplate,
-    ]
+    PKG_TEMPLATES_DIR = "templates"

    @cached_property
    def templates_dir(self):
        return os.path.join(self.dvc_dir, self.TEMPLATES_DIR)

-    def get_template(self, path):
-        if os.path.exists(path):
-            return path
+    @staticmethod
+    def _find(templates, template_name):
+        for template in templates:
+            if (
+                template_name == template
+                or template_name + ".json" == template
+            ):
+                return template
+        return None

-        if self.dvc_dir and os.path.exists(self.dvc_dir):
-            t_path = os.path.join(self.templates_dir, path)
-            if os.path.exists(t_path):
-                return t_path
+    def _find_in_project(self, name: str) -> Optional["StrPath"]:
+        if os.path.exists(name):
+            return name

-            all_templates = [
+        if os.path.exists(self.templates_dir):
+            templates = [
                os.path.join(root, file)
                for root, _, files in os.walk(self.templates_dir)
                for file in files
            ]
-            matches = [
-                template
-                for template in all_templates
-                if os.path.splitext(template)[0] == t_path
-            ]
-            if matches:
-                assert len(matches) == 1
-                return matches[0]
+            found = self._find(templates, name)
+            if found:
+                return os.path.join(self.templates_dir, found)
+        return None

-        raise TemplateNotFoundError(path)
+    @staticmethod
+    def _get_templates() -> Iterable[str]:
+        if (
+            importlib_resources.files(__package__)
+            .joinpath(PlotTemplates.PKG_TEMPLATES_DIR)
+            .is_dir()
+        ):
+            entries = (
+                importlib_resources.files(__package__)
+                .joinpath(PlotTemplates.PKG_TEMPLATES_DIR)
+                .iterdir()
+            )
+            return [entry.name for entry in entries]
+        return []
+
+    @staticmethod
+    def _load_from_pkg(name):
+        templates = PlotTemplates._get_templates()
+        found = PlotTemplates._find(templates, name)
+        if found:
+            return (
+                (
+                    importlib_resources.files(__package__)
+                    / PlotTemplates.PKG_TEMPLATES_DIR
+                    / found
+                )
+                .read_bytes()
+                .decode("utf-8")
+            )
+        return None
+
+    def load(self, name: str = None) -> Template:
+
+        if name is not None:
+            template_path = self._find_in_project(name)
+            if template_path:
+                with open(template_path, "r", encoding="utf-8") as fd:
+                    content = fd.read()
+                return Template(content, name)
+        else:
+            name = "linear"
+
+        content = self._load_from_pkg(name)
+        if content:
+            return Template(content, name)
+
+        raise TemplateNotFoundError(name)

    def __init__(self, dvc_dir):
        self.dvc_dir = dvc_dir
@@ -574,24 +186,18 @@ class PlotTemplates:
        from dvc.utils.fs import makedirs

        makedirs(self.templates_dir, exist_ok=True)
-        for t in self.TEMPLATES:
-            self._dump(t())

-    def _dump(self, template):
-        path = os.path.join(self.templates_dir, template.filename)
-        with open(path, "w") as fd:
-            fd.write(template.content)
-
-    def load(self, name):
-        try:
-            path = self.get_template(name)
-
-            with open(path) as fd:
-                content = fd.read()
-
-            return Template(content, name=name)
-        except TemplateNotFoundError:
-            for template in self.TEMPLATES:
-                if template.DEFAULT_NAME == name:
-                    return template()
-            raise
+        templates = self._get_templates()
+        for template in templates:
+            content = (
+                importlib_resources.files(__package__)
+                .joinpath(PlotTemplates.PKG_TEMPLATES_DIR)
+                .joinpath(template)
+                .read_text()
+            )
+            with open(
+                os.path.join(self.templates_dir, template),
+                "w",
+                encoding="utf-8",
+            ) as fd:
+                fd.write(content)
@@ -0,0 +1,107 @@
+{
+    "$schema": "https://vega.github.io/schema/vega-lite/v5.json",
+    "data": {
+        "values": "<DVC_METRIC_DATA>"
+    },
+    "title": "<DVC_METRIC_TITLE>",
+    "facet": {
+        "field": "rev",
+        "type": "nominal"
+    },
+    "spec": {
+        "transform": [
+            {
+                "aggregate": [
+                    {
+                        "op": "count",
+                        "as": "xy_count"
+                    }
+                ],
+                "groupby": [
+                    "<DVC_METRIC_Y>",
+                    "<DVC_METRIC_X>"
+                ]
+            },
+            {
+                "impute": "xy_count",
+                "groupby": [
+                    "rev",
+                    "<DVC_METRIC_Y>"
+                ],
+                "key": "<DVC_METRIC_X>",
+                "value": 0
+            },
+            {
+                "impute": "xy_count",
+                "groupby": [
+                    "rev",
+                    "<DVC_METRIC_X>"
+                ],
+                "key": "<DVC_METRIC_Y>",
+                "value": 0
+            },
+            {
+                "joinaggregate": [
+                    {
+                        "op": "max",
+                        "field": "xy_count",
+                        "as": "max_count"
+                    }
+                ],
+                "groupby": []
+            },
+            {
+                "calculate": "datum.xy_count / datum.max_count",
+                "as": "percent_of_max"
+            }
+        ],
+        "encoding": {
+            "x": {
+                "field": "<DVC_METRIC_X>",
+                "type": "nominal",
+                "sort": "ascending",
+                "title": "<DVC_METRIC_X_LABEL>"
+            },
+            "y": {
+                "field": "<DVC_METRIC_Y>",
+                "type": "nominal",
+                "sort": "ascending",
+                "title": "<DVC_METRIC_Y_LABEL>"
+            }
+        },
+        "layer": [
+            {
+                "mark": "rect",
+                "width": 300,
+                "height": 300,
+                "encoding": {
+                    "color": {
+                        "field": "xy_count",
+                        "type": "quantitative",
+                        "title": "",
+                        "scale": {
+                            "domainMin": 0,
+                            "nice": true
+                        }
+                    }
+                }
+            },
+            {
+                "mark": "text",
+                "encoding": {
+                    "text": {
+                        "field": "xy_count",
+                        "type": "quantitative"
+                    },
+                    "color": {
+                        "condition": {
+                            "test": "datum.percent_of_max > 0.5",
+                            "value": "white"
+                        },
+                        "value": "black"
+                    }
+                }
+            }
+        ]
+    }
+}
@@ -0,0 +1,112 @@
+{
+    "$schema": "https://vega.github.io/schema/vega-lite/v5.json",
+    "data": {
+        "values": "<DVC_METRIC_DATA>"
+    },
+    "title": "<DVC_METRIC_TITLE>",
+    "facet": {
+        "field": "rev",
+        "type": "nominal"
+    },
+    "spec": {
+        "transform": [
+            {
+                "aggregate": [
+                    {
+                        "op": "count",
+                        "as": "xy_count"
+                    }
+                ],
+                "groupby": [
+                    "<DVC_METRIC_Y>",
+                    "<DVC_METRIC_X>"
+                ]
+            },
+            {
+                "impute": "xy_count",
+                "groupby": [
+                    "rev",
+                    "<DVC_METRIC_Y>"
+                ],
+                "key": "<DVC_METRIC_X>",
+                "value": 0
+            },
+            {
+                "impute": "xy_count",
+                "groupby": [
+                    "rev",
+                    "<DVC_METRIC_X>"
+                ],
+                "key": "<DVC_METRIC_Y>",
+                "value": 0
+            },
+            {
+                "joinaggregate": [
+                    {
+                        "op": "sum",
+                        "field": "xy_count",
+                        "as": "sum_y"
+                    }
+                ],
+                "groupby": [
+                    "<DVC_METRIC_Y>"
+                ]
+            },
+            {
+                "calculate": "datum.xy_count / datum.sum_y",
+                "as": "percent_of_y"
+            }
+        ],
+        "encoding": {
+            "x": {
+                "field": "<DVC_METRIC_X>",
+                "type": "nominal",
+                "sort": "ascending",
+                "title": "<DVC_METRIC_X_LABEL>"
+            },
+            "y": {
+                "field": "<DVC_METRIC_Y>",
+                "type": "nominal",
+                "sort": "ascending",
+                "title": "<DVC_METRIC_Y_LABEL>"
+            }
+        },
+        "layer": [
+            {
+                "mark": "rect",
+                "width": 300,
+                "height": 300,
+                "encoding": {
+                    "color": {
+                        "field": "percent_of_y",
+                        "type": "quantitative",
+                        "title": "",
+                        "scale": {
+                            "domain": [
+                                0,
+                                1
+                            ]
+                        }
+                    }
+                }
+            },
+            {
+                "mark": "text",
+                "encoding": {
+                    "text": {
+                        "field": "percent_of_y",
+                        "type": "quantitative",
+                        "format": ".2f"
+                    },
+                    "color": {
+                        "condition": {
+                            "test": "datum.percent_of_y > 0.5",
+                            "value": "white"
+                        },
+                        "value": "black"
+                    }
+                }
+            }
+        ]
+    }
+}
@@ -0,0 +1,116 @@
+{
+    "$schema": "https://vega.github.io/schema/vega-lite/v5.json",
+    "data": {
+        "values": "<DVC_METRIC_DATA>"
+    },
+    "title": "<DVC_METRIC_TITLE>",
+    "width": 300,
+    "height": 300,
+    "layer": [
+        {
+            "encoding": {
+                "x": {
+                    "field": "<DVC_METRIC_X>",
+                    "type": "quantitative",
+                    "title": "<DVC_METRIC_X_LABEL>"
+                },
+                "y": {
+                    "field": "<DVC_METRIC_Y>",
+                    "type": "quantitative",
+                    "title": "<DVC_METRIC_Y_LABEL>",
+                    "scale": {
+                        "zero": false
+                    }
+                },
+                "color": {
+                    "field": "rev",
+                    "type": "nominal"
+                }
+            },
+            "layer": [
+                {
+                    "mark": "line"
+                },
+                {
+                    "selection": {
+                        "label": {
+                            "type": "single",
+                            "nearest": true,
+                            "on": "mouseover",
+                            "encodings": [
+                                "x"
+                            ],
+                            "empty": "none",
+                            "clear": "mouseout"
+                        }
+                    },
+                    "mark": "point",
+                    "encoding": {
+                        "opacity": {
+                            "condition": {
+                                "selection": "label",
+                                "value": 1
+                            },
+                            "value": 0
+                        }
+                    }
+                }
+            ]
+        },
+        {
+            "transform": [
+                {
+                    "filter": {
+                        "selection": "label"
+                    }
+                }
+            ],
+            "layer": [
+                {
+                    "mark": {
+                        "type": "rule",
+                        "color": "gray"
+                    },
+                    "encoding": {
+                        "x": {
+                            "field": "<DVC_METRIC_X>",
+                            "type": "quantitative"
+                        }
+                    }
+                },
+                {
+                    "encoding": {
+                        "text": {
+                            "type": "quantitative",
+                            "field": "<DVC_METRIC_Y>"
+                        },
+                        "x": {
+                            "field": "<DVC_METRIC_X>",
+                            "type": "quantitative"
+                        },
+                        "y": {
+                            "field": "<DVC_METRIC_Y>",
+                            "type": "quantitative"
+                        }
+                    },
+                    "layer": [
+                        {
+                            "mark": {
+                                "type": "text",
+                                "align": "left",
+                                "dx": 5,
+                                "dy": -5
+                            },
+                            "encoding": {
+                                "color": {
+                                    "type": "nominal",
+                                    "field": "rev"
+                                }
+                            }
+                        }
+                    ]
+                }
+            ]
+        }
+    ]
+}
@@ -0,0 +1,104 @@
+{
+    "$schema": "https://vega.github.io/schema/vega-lite/v5.json",
+    "data": {
+        "values": "<DVC_METRIC_DATA>"
+    },
+    "title": "<DVC_METRIC_TITLE>",
+    "width": 300,
+    "height": 300,
+    "layer": [
+        {
+            "encoding": {
+                "x": {
+                    "field": "<DVC_METRIC_X>",
+                    "type": "quantitative",
+                    "title": "<DVC_METRIC_X_LABEL>"
+                },
+                "y": {
+                    "field": "<DVC_METRIC_Y>",
+                    "type": "quantitative",
+                    "title": "<DVC_METRIC_Y_LABEL>",
+                    "scale": {
+                        "zero": false
+                    }
+                },
+                "color": {
+                    "field": "rev",
+                    "type": "nominal"
+                }
+            },
+            "layer": [
+                {
+                    "mark": "point"
+                },
+                {
+                    "selection": {
+                        "label": {
+                            "type": "single",
+                            "nearest": true,
+                            "on": "mouseover",
+                            "encodings": [
+                                "x"
+                            ],
+                            "empty": "none",
+                            "clear": "mouseout"
+                        }
+                    },
+                    "mark": "point",
+                    "encoding": {
+                        "opacity": {
+                            "condition": {
+                                "selection": "label",
+                                "value": 1
+                            },
+                            "value": 0
+                        }
+                    }
+                }
+            ]
+        },
+        {
+            "transform": [
+                {
+                    "filter": {
+                        "selection": "label"
+                    }
+                }
+            ],
+            "layer": [
+                {
+                    "encoding": {
+                        "text": {
+                            "type": "quantitative",
+                            "field": "<DVC_METRIC_Y>"
+                        },
+                        "x": {
+                            "field": "<DVC_METRIC_X>",
+                            "type": "quantitative"
+                        },
+                        "y": {
+                            "field": "<DVC_METRIC_Y>",
+                            "type": "quantitative"
+                        }
+                    },
+                    "layer": [
+                        {
+                            "mark": {
+                                "type": "text",
+                                "align": "left",
+                                "dx": 5,
+                                "dy": -5
+                            },
+                            "encoding": {
+                                "color": {
+                                    "type": "nominal",
+                                    "field": "rev"
+                                }
+                            }
+                        }
+                    ]
+                }
+            ]
+        }
+    ]
+}
@@ -0,0 +1,31 @@
+{
+    "$schema": "https://vega.github.io/schema/vega-lite/v5.json",
+    "data": {
+        "values": "<DVC_METRIC_DATA>"
+    },
+    "title": "<DVC_METRIC_TITLE>",
+    "width": 300,
+    "height": 300,
+    "mark": {
+        "type": "line"
+    },
+    "encoding": {
+        "x": {
+            "field": "<DVC_METRIC_X>",
+            "type": "quantitative",
+            "title": "<DVC_METRIC_X_LABEL>"
+        },
+        "y": {
+            "field": "<DVC_METRIC_Y>",
+            "type": "quantitative",
+            "title": "<DVC_METRIC_Y_LABEL>",
+            "scale": {
+                "zero": false
+            }
+        },
+        "color": {
+            "field": "rev",
+            "type": "nominal"
+        }
+    }
+}
@@ -0,0 +1,39 @@
+{
+    "$schema": "https://vega.github.io/schema/vega-lite/v5.json",
+    "data": {
+        "values": "<DVC_METRIC_DATA>"
+    },
+    "title": "<DVC_METRIC_TITLE>",
+    "mark": {
+        "type": "line"
+    },
+    "encoding": {
+        "x": {
+            "field": "<DVC_METRIC_X>",
+            "type": "quantitative",
+            "title": "<DVC_METRIC_X_LABEL>"
+        },
+        "y": {
+            "field": "<DVC_METRIC_Y>",
+            "type": "quantitative",
+            "title": "<DVC_METRIC_Y_LABEL>",
+            "scale": {
+                "zero": false
+            }
+        },
+        "color": {
+            "field": "rev",
+            "type": "nominal"
+        }
+    },
+    "transform": [
+        {
+            "loess": "<DVC_METRIC_Y>",
+            "on": "<DVC_METRIC_X>",
+            "groupby": [
+                "rev"
+            ],
+            "bandwidth": 0.3
+        }
+    ]
+}
@@ -35,7 +35,7 @@ class RWLockFileFormatError(DvcException):
 def _edit_rwlock(lock_dir):
    path = os.path.join(lock_dir, "rwlock")
    try:
-        with open(path) as fobj:
+        with open(path, encoding="utf-8") as fobj:
            lock = SCHEMA(json.load(fobj))
    except FileNotFoundError:
        lock = SCHEMA({})
@@ -46,7 +46,7 @@ def _edit_rwlock(lock_dir):
    lock["read"] = defaultdict(list, lock["read"])
    lock["write"] = defaultdict(dict, lock["write"])
    yield lock
-    with open(path, "w+") as fobj:
+    with open(path, "w+", encoding="utf-8") as fobj:
        json.dump(lock, fobj)


@@ -1,7 +1,9 @@
+from collections.abc import Mapping
+
 from voluptuous import Any, Optional, Required, Schema

 from dvc import dependency, output
-from dvc.hash_info import HashInfo
+from dvc.objects.meta import Meta
 from dvc.output import CHECKSUMS_SCHEMA, Output
 from dvc.parsing import DO_KWD, FOREACH_KWD, VARS_KWD
 from dvc.parsing.versions import SCHEMA_KWD, lockfile_version_schema
@@ -24,8 +26,8 @@ SINGLE_STAGE_SCHEMA = {
 DATA_SCHEMA = {
    **CHECKSUMS_SCHEMA,
    Required("path"): str,
-    HashInfo.PARAM_SIZE: int,
-    HashInfo.PARAM_NFILES: int,
+    Meta.PARAM_SIZE: int,
+    Meta.PARAM_NFILES: int,
    Output.PARAM_ISEXEC: bool,
 }
 LOCK_FILE_STAGE_SCHEMA = {
@@ -94,11 +96,27 @@ STAGE_DEFINITION = {
    Optional(StageParams.PARAM_LIVE): Any(str, LIVE_PSTAGE_SCHEMA),
 }

+
+def either_or(primary, fallback, fallback_includes=None):
+    def validator(data):
+        schema = primary
+        if (
+            isinstance(data, Mapping)
+            and set(fallback_includes or []) & data.keys()
+        ):
+            schema = fallback
+        return Schema(schema)(data)
+
+    return validator
+
+
 FOREACH_IN = {
    Required(FOREACH_KWD): Any(dict, list, str),
    Required(DO_KWD): STAGE_DEFINITION,
 }
-SINGLE_PIPELINE_STAGE_SCHEMA = {str: Any(FOREACH_IN, STAGE_DEFINITION)}
+SINGLE_PIPELINE_STAGE_SCHEMA = {
+    str: either_or(STAGE_DEFINITION, FOREACH_IN, [FOREACH_KWD, DO_KWD])
+}
 MULTI_STAGE_SCHEMA = {
    STAGES: SINGLE_PIPELINE_STAGE_SCHEMA,
    VARS_KWD: VARS_SCHEMA,
@@ -0,0 +1,48 @@
+"""DVC re-implementation of fsspec's dedicated async event loop."""
+import asyncio
+import os
+import threading
+from typing import List, Optional
+
+from fsspec.asyn import (  # noqa: F401, pylint:disable=unused-import
+    _selector_policy,
+    sync,
+    sync_wrapper,
+)
+
+# dedicated async IO thread
+iothread: List[Optional[threading.Thread]] = [None]
+# global DVC event loop
+default_loop: List[Optional[asyncio.AbstractEventLoop]] = [None]
+lock = threading.Lock()
+
+
+def get_loop() -> asyncio.AbstractEventLoop:
+    """Create or return the global DVC event loop."""
+    if default_loop[0] is None:
+        with lock:
+            if default_loop[0] is None:
+                with _selector_policy():
+                    default_loop[0] = asyncio.new_event_loop()
+                loop = default_loop[0]
+                th = threading.Thread(
+                    target=loop.run_forever,  # type: ignore[attr-defined]
+                    name="dvcIO",
+                )
+                th.daemon = True
+                th.start()
+                iothread[0] = th
+    assert default_loop[0] is not None
+    return default_loop[0]
+
+
+class BaseAsyncObject:
+    def __init__(self, loop: Optional[asyncio.AbstractEventLoop] = None):
+        self._loop: asyncio.AbstractEventLoop = loop or get_loop()
+        self._pid = os.getpid()
+
+    @property
+    def loop(self):
+        # AsyncMixin is not fork-safe
+        assert self._pid == os.getpid()
+        return self._loop
@@ -195,7 +195,7 @@ class Git(Base):
        if not os.path.exists(gitignore):
            return

-        with open(gitignore) as fobj:
+        with open(gitignore, encoding="utf-8") as fobj:
            lines = fobj.readlines()

        filtered = list(filter(lambda x: x.strip() != entry.strip(), lines))
@@ -204,14 +204,14 @@ class Git(Base):
            os.unlink(gitignore)
            return

-        with open(gitignore, "w") as fobj:
+        with open(gitignore, "w", encoding="utf-8") as fobj:
            fobj.writelines(filtered)

        self.track_file(relpath(gitignore))

    def _install_hook(self, name):
        hook = self._hook_path(name)
-        with open(hook, "w+") as fobj:
+        with open(hook, "w+", encoding="utf-8") as fobj:
            fobj.write(f"#!/bin/sh\nexec dvc git-hook {name} $@\n")

        os.chmod(hook, 0o777)
@@ -265,6 +265,9 @@ class Git(Base):
                ],
            }

+            if "repos" not in config:
+                config["repos"] = []
+
            if entry not in config["repos"]:
                config["repos"].append(entry)

@@ -178,7 +178,7 @@ class BaseGitBackend(ABC):
        """

    @abstractmethod
-    def iter_remote_refs(self, url: str, base: Optional[str] = None):
+    def iter_remote_refs(self, url: str, base: Optional[str] = None, **kwargs):
        """Iterate over all refs in the specified remote Git repo.

        If base is specified, only refs which begin with base will be yielded.
@@ -197,6 +197,7 @@ class BaseGitBackend(ABC):
        dest: str,
        force: bool = False,
        on_diverged: Optional[Callable[[str, str], bool]] = None,
+        **kwargs,
    ):
        """Push refspec to a remote Git repo.

@@ -222,6 +223,7 @@ class BaseGitBackend(ABC):
        refspecs: Iterable[str],
        force: Optional[bool] = False,
        on_diverged: Optional[Callable[[str, str], bool]] = None,
+        **kwargs,
    ):
        """Fetch refspecs from a remote Git repo.

@@ -349,5 +351,5 @@ class BaseGitBackend(ABC):
        """

    @abstractmethod
-    def validate_git_remote(self, url: str):
+    def validate_git_remote(self, url: str, **kwargs):
        """Verify that url is a valid git URL or remote name."""
@@ -23,13 +23,13 @@ from dvc.progress import Tqdm
 from dvc.scm.base import GitAuthError, InvalidRemoteSCMRepo, SCMError
 from dvc.utils import relpath

-from ..objects import GitObject
-from .base import BaseGitBackend
+from ...objects import GitObject
+from ..base import BaseGitBackend

 if TYPE_CHECKING:
    from dvc.types import StrPath

-    from ..objects import GitCommit
+    from ...objects import GitCommit

 logger = logging.getLogger(__name__)

@@ -80,6 +80,13 @@ class DulwichObject(GitObject):
 class DulwichBackend(BaseGitBackend):  # pylint:disable=abstract-method
    """Dulwich Git backend."""

+    from dulwich import client
+
+    from .asyncssh_vendor import AsyncSSHVendor
+
+    # monkeypatch dulwich client's default SSH vendor to use asyncssh
+    client.get_ssh_vendor = AsyncSSHVendor
+
    # Dulwich progress will return messages equivalent to git CLI,
    # our pbars should just display the messages as formatted by dulwich
    BAR_FMT_NOTOTAL = "{desc}{bar:b}|{postfix[info]} [{elapsed}]"
@@ -354,14 +361,14 @@ class DulwichBackend(BaseGitBackend):  # pylint:disable=abstract-method
            else:
                yield os.fsdecode(key)

-    def iter_remote_refs(self, url: str, base: Optional[str] = None):
+    def iter_remote_refs(self, url: str, base: Optional[str] = None, **kwargs):
        from dulwich.client import HTTPUnauthorized, get_transport_and_path
        from dulwich.errors import NotGitRepository
        from dulwich.porcelain import get_remote_repo

        try:
            _remote, location = get_remote_repo(self.repo, url)
-            client, path = get_transport_and_path(location)
+            client, path = get_transport_and_path(location, **kwargs)
        except Exception as exc:
            raise InvalidRemoteSCMRepo(url) from exc

@@ -389,6 +396,7 @@ class DulwichBackend(BaseGitBackend):  # pylint:disable=abstract-method
        dest: str,
        force: bool = False,
        on_diverged: Optional[Callable[[str, str], bool]] = None,
+        **kwargs,
    ):
        from dulwich.client import HTTPUnauthorized, get_transport_and_path
        from dulwich.errors import NotGitRepository, SendPackError
@@ -402,7 +410,7 @@ class DulwichBackend(BaseGitBackend):  # pylint:disable=abstract-method

        try:
            _remote, location = get_remote_repo(self.repo, url)
-            client, path = get_transport_and_path(location)
+            client, path = get_transport_and_path(location, **kwargs)
        except Exception as exc:
            raise SCMError(
                f"'{url}' is not a valid Git remote or URL"
@@ -476,6 +484,7 @@ class DulwichBackend(BaseGitBackend):  # pylint:disable=abstract-method
        refspecs: Iterable[str],
        force: Optional[bool] = False,
        on_diverged: Optional[Callable[[str, str], bool]] = None,
+        **kwargs,
    ):
        from dulwich.client import get_transport_and_path
        from dulwich.objectspec import parse_reftuples
@@ -504,7 +513,7 @@ class DulwichBackend(BaseGitBackend):  # pylint:disable=abstract-method

        try:
            _remote, location = get_remote_repo(self.repo, url)
-            client, path = get_transport_and_path(location)
+            client, path = get_transport_and_path(location, **kwargs)
        except Exception as exc:
            raise SCMError(
                f"'{url}' is not a valid Git remote or URL"
@@ -659,13 +668,13 @@ class DulwichBackend(BaseGitBackend):  # pylint:disable=abstract-method
    ) -> Optional[str]:
        raise NotImplementedError

-    def validate_git_remote(self, url: str):
+    def validate_git_remote(self, url: str, **kwargs):
        from dulwich.client import LocalGitClient, get_transport_and_path
        from dulwich.porcelain import get_remote_repo

        try:
            _, location = get_remote_repo(self.repo, url)
-            client, path = get_transport_and_path(location)
+            client, path = get_transport_and_path(location, **kwargs)
        except Exception as exc:
            raise InvalidRemoteSCMRepo(url) from exc
        if isinstance(client, LocalGitClient) and not os.path.exists(
@@ -0,0 +1,92 @@
+"""asyncssh SSH vendor for Dulwich."""
+from typing import List, Optional
+
+from dulwich.client import SSHVendor
+
+from dvc.scm.asyn import BaseAsyncObject, sync_wrapper
+
+
+class _StderrWrapper:
+    def __init__(self, stderr):
+        self.stderr = stderr
+
+    async def _readlines(self):
+        lines = []
+        while True:
+            line = await self.stderr.readline()
+            if not line:
+                break
+            lines.append(line)
+        return lines
+
+    readlines = sync_wrapper(_readlines)
+
+
+class AsyncSSHWrapper(BaseAsyncObject):
+    def __init__(self, conn, proc, **kwargs):
+        super().__init__(**kwargs)
+        self.conn = conn
+        self.proc = proc
+        self.stderr = _StderrWrapper(proc.stderr)
+
+    def can_read(self) -> bool:
+        # pylint:disable=protected-access
+        return self.proc.stdout._session._recv_buf_len > 0
+
+    async def _read(self, n: Optional[int] = None) -> bytes:
+        if self.proc.stdout.at_eof():
+            return b""
+
+        return await self.proc.stdout.read(n=n if n is not None else -1)
+
+    read = sync_wrapper(_read)
+
+    def write(self, data: bytes):
+        self.proc.stdin.write(data)
+
+    def close(self):
+        self.conn.close()
+
+
+class AsyncSSHVendor(BaseAsyncObject, SSHVendor):
+    def __init__(self, **kwargs):
+        super().__init__(**kwargs)
+
+    async def _run_command(
+        self,
+        host: str,
+        command: List[str],
+        username: Optional[str] = None,
+        port: Optional[int] = None,
+        password: Optional[str] = None,
+        key_filename: Optional[str] = None,
+        **kwargs,
+    ):
+        """Connect to an SSH server.
+
+        Run a command remotely and return a file-like object for interaction
+        with the remote command.
+
+        Args:
+          host: Host name
+          command: Command to run (as argv array)
+          username: Optional ame of user to log in as
+          port: Optional SSH port to use
+          password: Optional ssh password for login or private key
+          key_filename: Optional path to private keyfile
+        """
+        import asyncssh
+
+        conn = await asyncssh.connect(
+            host,
+            port=port,
+            username=username,
+            password=password,
+            client_keys=[key_filename] if key_filename else [],
+            known_hosts=None,
+            encoding=None,
+        )
+        proc = await conn.create_process(command, encoding=None)
+        return AsyncSSHWrapper(conn, proc)
+
+    run_command = sync_wrapper(_run_command)
@@ -438,7 +438,7 @@ class GitPythonBackend(BaseGitBackend):  # pylint:disable=abstract-method
        for ref in Reference.iter_items(self.repo, common_path=base):
            yield ref.path

-    def iter_remote_refs(self, url: str, base: Optional[str] = None):
+    def iter_remote_refs(self, url: str, base: Optional[str] = None, **kwargs):
        raise NotImplementedError

    def get_refs_containing(self, rev: str, pattern: Optional[str] = None):
@@ -465,6 +465,7 @@ class GitPythonBackend(BaseGitBackend):  # pylint:disable=abstract-method
        dest: str,
        force: bool = False,
        on_diverged: Optional[Callable[[str, str], bool]] = None,
+        **kwargs,
    ):
        raise NotImplementedError

@@ -474,6 +475,7 @@ class GitPythonBackend(BaseGitBackend):  # pylint:disable=abstract-method
        refspecs: Iterable[str],
        force: Optional[bool] = False,
        on_diverged: Optional[Callable[[str, str], bool]] = None,
+        **kwargs,
    ):
        raise NotImplementedError

@@ -627,5 +629,5 @@ class GitPythonBackend(BaseGitBackend):  # pylint:disable=abstract-method
            raise SCMError("Merge failed") from exc
        return None

-    def validate_git_remote(self, url: str):
+    def validate_git_remote(self, url: str, **kwargs):
        raise NotImplementedError
@@ -374,6 +374,7 @@ class Pygit2Backend(BaseGitBackend):  # pylint:disable=abstract-method
        dest: str,
        force: bool = False,
        on_diverged: Optional[Callable[[str, str], bool]] = None,
+        **kwargs,
    ):
        raise NotImplementedError

@@ -383,6 +384,7 @@ class Pygit2Backend(BaseGitBackend):  # pylint:disable=abstract-method
        refspecs: Iterable[str],
        force: Optional[bool] = False,
        on_diverged: Optional[Callable[[str, str], bool]] = None,
+        **kwargs,
    ):
        raise NotImplementedError

@@ -537,7 +539,7 @@ class Pygit2Backend(BaseGitBackend):  # pylint:disable=abstract-method
                    index.add(entry.path)
                index.write()

-    def iter_remote_refs(self, url: str, base: Optional[str] = None):
+    def iter_remote_refs(self, url: str, base: Optional[str] = None, **kwargs):
        raise NotImplementedError

    def status(
@@ -584,5 +586,5 @@ class Pygit2Backend(BaseGitBackend):  # pylint:disable=abstract-method
                self.repo.index.write()
        return None

-    def validate_git_remote(self, url: str):
+    def validate_git_remote(self, url: str, **kwargs):
        raise NotImplementedError
@@ -273,7 +273,7 @@ class Stage(params.StageParams):
            from dvc.output import Output
            from dvc.schema import LIVE_PROPS

-            env[DVCLIVE_PATH] = str(out.path_info)
+            env[DVCLIVE_PATH] = relpath(out.path_info, self.wdir)
            if isinstance(out.live, dict):
                config = project(out.live, LIVE_PROPS)

@@ -19,13 +19,11 @@ class RunCacheNotFoundError(DvcException):


 def _get_cache_hash(cache, key=False):
-    from dvc.hash_info import HashInfo
+    from dvc.objects.meta import Meta

    if key:
        cache["outs"] = [out["path"] for out in cache.get("outs", [])]
-    return dict_sha256(
-        cache, exclude=[HashInfo.PARAM_SIZE, HashInfo.PARAM_NFILES]
-    )
+    return dict_sha256(cache, exclude=[Meta.PARAM_SIZE, Meta.PARAM_NFILES])


 def _can_hash(stage):
@@ -9,10 +9,6 @@ class StageCmdFailedError(DvcException):
        super().__init__(msg)


-class StageFileFormatError(DvcException):
-    pass
-
-
 class StageFileDoesNotExistError(DvcException):
    DVC_IGNORED = "is dvc-ignored"
    DOES_NOT_EXIST = "does not exist"
@@ -7,6 +7,7 @@ from funcy import cached_property, get_in, lcat, once, project

 from dvc import dependency, output
 from dvc.hash_info import HashInfo
+from dvc.objects.meta import Meta
 from dvc.parsing import FOREACH_KWD, JOIN, DataResolver, EntryNotFound
 from dvc.parsing.versions import LOCKFILE_VERSION
 from dvc.path_info import PathInfo
@@ -69,6 +70,7 @@ class StageLoader(Mapping):
            info = info.copy()
            info.pop("path", None)
            item.isexec = info.pop("isexec", None)
+            item.meta = Meta.from_dict(info)
            item.hash_info = HashInfo.from_dict(info)

    @classmethod
@@ -164,6 +164,7 @@ def to_single_stage_lockfile(stage: "Stage") -> dict:
        ret = [
            (item.PARAM_PATH, item.def_path),
            *item.hash_info.to_dict().items(),
+            *item.meta.to_dict().items(),
        ]

        if item.isexec:
--- a/Show More
+++ b/Show More