api: Add scm module with all_{X} methods for listing revs.

dvc/api/__init__.py

@@ -3,9 +3,13 @@ from dvc.fs.dvc import _DVCFileSystem as DVCFileSystem
 from .data import open  # pylint: disable=redefined-builtin
 from .data import get_url, read
 from .experiments import exp_save, exp_show, make_checkpoint
+from .scm import all_branches, all_commits, all_tags
 from .show import metrics_show, params_show
 
 __all__ = [
+    "all_branches",
+    "all_commits",
+    "all_tags",
     "exp_save",
     "exp_show",
     "get_url",

dvc/api/scm.py

@@ -0,0 +1,54 @@
+from typing import List, Optional
+
+from dvc.repo import Repo
+
+
+def all_branches(repo: Optional[str] = None) -> List[str]:
+    """Get all Git branches in a DVC repository.
+
+    Args:
+        repo (str, optional): location of the DVC repository.
+            Defaults to the current project (found by walking up from the
+            current working directory tree).
+            It can be a URL or a file system path.
+            Both HTTP and SSH protocols are supported for online Git repos
+            (e.g. [user@]server:project.git).
+    Returns:
+        List[str]: Names of the Git branches.
+    """
+    with Repo.open(repo) as _repo:
+        return _repo.scm.list_branches()
+
+
+def all_commits(repo: Optional[str] = None) -> List[str]:
+    """Get all Git commits in a DVC repository.
+
+    Args:
+        repo (str, optional): location of the DVC repository.
+            Defaults to the current project (found by walking up from the
+            current working directory tree).
+            It can be a URL or a file system path.
+            Both HTTP and SSH protocols are supported for online Git repos
+            (e.g. [user@]server:project.git).
+    Returns:
+        List[str]: SHAs of the Git commits.
+    """
+    with Repo.open(repo) as _repo:
+        return _repo.scm.list_all_commits()
+
+
+def all_tags(repo: Optional[str] = None) -> List[str]:
+    """Get all Git tags in a DVC repository.
+
+    Args:
+        repo (str, optional): location of the DVC repository.
+            Defaults to the current project (found by walking up from the
+            current working directory tree).
+            It can be a URL or a file system path.
+            Both HTTP and SSH protocols are supported for online Git repos
+            (e.g. [user@]server:project.git).
+    Returns:
+        List[str]: Names of the Git tags.
+    """
+    with Repo.open(repo) as _repo:
+        return _repo.scm.list_tags()

tests/func/api/test_scm.py

@@ -0,0 +1,30 @@
+from dvc.api.scm import all_branches, all_commits, all_tags
+
+
+def test_all_branches(tmp_dir, scm, dvc):
+    assert all_branches() == ["master"]
+
+    with tmp_dir.branch("branch", new=True):
+        tmp_dir.scm_gen("branch", "branch", "commit")
+
+    assert all_branches() == ["branch", "master"]
+
+
+def test_all_commits(tmp_dir, scm, dvc):
+    first = scm.get_rev()
+    assert all_commits() == [first]
+
+    tmp_dir.scm_gen("foo", "foo", "commit")
+    second = scm.get_rev()
+
+    assert set(all_commits()) == {first, second}
+
+
+def test_all_tags(tmp_dir, scm, dvc):
+    scm.tag("v1")
+    assert all_tags() == ["v1"]
+
+    tmp_dir.scm_gen("foo", "foo", "commit")
+    scm.tag("v2")
+
+    assert set(all_tags()) == {"v1", "v2"}