hashlib.sha256(repo.encode()).hexdigest()))
-def verify_ancestry(repo: Repo, ref: Ref, rev: Rev) -> None:
+def is_ancestor(repo: Repo, ref: Ref, rev: Rev) -> bool:
cachedir = git_cachedir(repo)
- logging.debug('Verifying rev %s is an ancestor of ref "%s"', rev, ref)
- subprocess.run(['git', '-C', cachedir, 'merge-base', '--is-ancestor',
- rev, ref], check=True)
+ logging.debug('Checking if rev %s is an ancestor of ref "%s"', rev, ref)
+ process = subprocess.run(
+ ['git', '-C', cachedir, 'merge-base', '--is-ancestor', rev, ref], check=False)
+ return process.returncode == 0
+
+
+def verify_ancestry(repo: Repo, ref: Ref, rev: Rev) -> None:
+ if not is_ancestor(repo, ref, rev):
+ raise Exception('Rev %s is not an ancestor of ref "%s"' % (rev, ref))
@backoff.on_exception(
def ensure_rev_available(repo: Repo, ref: Ref, rev: Rev) -> Path:
cachedir = git_cachedir(repo)
- if os.path.exists(cachedir):
- logging.debug('Checking if we already have rev %s', rev)
- process = subprocess.run(
- ['git', '-C', cachedir, 'cat-file', '-e', rev], check=False)
- if process.returncode == 0:
- logging.debug('We already have rev %s', rev)
- verify_ancestry(repo, ref, rev)
- return cachedir
- if process.returncode != 1:
- raise Exception(
- 'Could not test for presence of rev %s. Is cache dir "%s" messed up?' %
- (rev, cachedir))
+ if os.path.exists(cachedir) and is_ancestor(repo, ref, rev):
+ return cachedir
logging.debug(
'We do not have rev %s. We will fetch ref "%s" and hope it appears.',
fetch(repo, ref)
logging.debug('Verifying that fetch retrieved rev %s', rev)
subprocess.run(['git', '-C', cachedir, 'cat-file', '-e', rev], check=True)
+ verify_ancestry(repo, ref, rev)
return cachedir
d = git_cache.ensure_rev_available(self.upstream, 'otherbranch', rev)
self.assertEqual(_git(d, 'show', '%s:foofile' % rev), b'foo')
+ def test_catch_up(self) -> None:
+ _git(self.upstream, 'checkout', '-b', 'otherbranch')
+ _commit_file(self.upstream, 'foofile', 'foo', 'Foo')
+ rev = _git(self.upstream, 'log', '--format=%H', '-n1').strip().decode()
+ d = git_cache.ensure_rev_available(self.upstream, 'otherbranch', rev)
+ self.assertEqual(_git(d, 'show', '%s:foofile' % rev), b'foo')
+ _git(self.upstream, 'checkout', 'master')
+ _git(self.upstream, 'merge', '--ff-only', 'otherbranch')
+ d = git_cache.ensure_rev_available(self.upstream, 'master', rev)
+ self.assertEqual(_git(d, 'show', '%s:foofile' % rev), b'foo')
+
def test_fetch_after_cache_deleted(self) -> None:
d1, rev1 = git_cache.fetch(self.upstream, 'master')
shutil.rmtree(d1)