Optimize ignore performance (#4120)

* Remove Duplicate ignore Match

* Continue Optimize Dvcignore

fix #3869

* Add a new test with multi ignore files

* Solve merging two dvc files

* Solve Code Climate

* For Windows

* Complete addition of patterns. Add one test

* Systematic test

* Change request

* Change request

* Seperate path sepcification math

* Rename and add comment

* rename change_dirname to private

* Update dvc/pathspec_math.py

list comprehension

Co-authored-by: Alexander Schepanovski <[email protected]>

* Change request

* Update dvc/ignore.py

Co-authored-by: karajan1001 <[email protected]>
Co-authored-by: Alexander Schepanovski <[email protected]>
Co-authored-by: Ruslan Kuprieiev <[email protected]>

tests/unit/test_pathspec_math.py

@@ -0,0 +1,72 @@
+import pytest
+
+from dvc.pathspec_math import _change_dirname
+
+
+@pytest.mark.parametrize(
+    "patterns, dirname, changed",
+    [
+        # A line starting with # serves as a comment.
+        ("#comment", "/dir", "#comment"),
+        # Put a backslash ("\") in front of the first hash for patterns that
+        # begin with a hash.
+        ("\\#hash", "/dir", "/dir/**/#hash"),
+        ("\\#hash", "/#dir", "/#dir/**/#hash"),
+        # Trailing spaces are ignored unless they are quoted with
+        # backslash ("\").
+        (" space", "/dir", "/dir/**/space"),
+        ("\\ space", "/dir", "/dir/**/ space"),
+        # An optional prefix "!" which negates the pattern;
+        ("!include", "/dir", "!/dir/**/include"),
+        # Put a backslash ("\") in front of the first "!" for patterns that
+        # begin with a literal "!", for example, "\!important!.txt".
+        ("\\!important!.txt", "/dir", "/dir/**/!important!.txt"),
+        # If there is a separator at the beginning or middle (or both) of the
+        # pattern, then the pattern is relative to the directory level of the
+        # particular .gitignore file itself.
+        ("/separator.txt", "/dir", "/dir/separator.txt"),
+        ("subdir/separator.txt", "/dir", "/dir/subdir/separator.txt"),
+        # Otherwise the pattern may also match at any level below
+        # the .gitignore level.
+        ("no_sep", "/dir", "/dir/**/no_sep"),
+        # If there is a separator at the end of the pattern then the pattern
+        # will only match directories, otherwise the pattern can match both
+        # files and directories.
+        ("doc/fortz/", "/dir", "/dir/doc/fortz/"),
+        ("fortz/", "/dir", "/dir/**/fortz/"),
+        # An asterisk "*" matches anything except a slash.
+        ("*aste*risk*", "/dir", "/dir/**/*aste*risk*"),
+        # The character "?" matches any one character except "/".
+        ("?fi?le?", "/dir", "/dir/**/?fi?le?"),
+        # The range notation, e.g. [a-zA-Z], can be used to match one of the
+        # characters in a range. See fnmatch(3) and the FNM_PATHNAME flag
+        # for a more detailed description.
+        ("[a-zA-Z]file[a-zA-Z]", "/dir", "/dir/**/[a-zA-Z]file[a-zA-Z]"),
+        # Two consecutive asterisks ("**") in patterns matched against full
+        # pathname may have special meaning:
+        # A leading "**" followed by a slash means match in all directories.
+        # For example, "**/foo" matches file or directory "foo" anywhere,
+        # the same as pattern "foo".
+        ("**/foo", "/dir", "/dir/**/foo"),
+        # "**/foo/bar" matches file or directory "bar" anywhere that is
+        # directly under directory "foo".
+        ("**/foo/bar", "/dir", "/dir/**/foo/bar"),
+        # A trailing "/**" matches everything inside.
+        # For example, "abc/**" matches all files inside directory "abc",
+        # relative to the location of the .gitignore file, with infinite depth.
+        ("abc/**", "/dir", "/dir/abc/**"),
+        # A slash followed by two consecutive asterisks then a slash matches
+        # zero or more directories. For example, "a/**/b"
+        # matches "a/b", "a/x/b", "a/x/y/b" and so on.
+        ("a/**/b", "/dir", "/dir/a/**/b"),
+        # Other consecutive asterisks are considered regular asterisks and
+        # will match according to the previous rules.
+        ("/***.txt", "/dir", "/dir/***.txt"),
+        ("data/***", "/dir", "/dir/data/***"),
+        ("***/file.txt", "/dir", "/dir/***/file.txt"),
+        ("***file", "/dir", "/dir/**/***file"),
+        ("a/***/b", "/dir", "/dir/a/***/b"),
+    ],
+)
+def test_dvcignore_pattern_change_dir(tmp_dir, patterns, dirname, changed):
+    assert _change_dirname(dirname, [patterns], "/") == [changed]