( )⚙ D11268 issue6528: implement _is_revision_affected_fast using callback

This is an archive of the discontinued Mercurial Phabricator instance.

Differential D11268

issue6528: implement _is_revision_affected_fast using callback
ClosedPublic

Authored by marmoute on Aug 7 2021, 10:07 AM.

Details

Reviewers
pulkit
Group Reviewers
hg-reviewers
Commits
rHGc02ce6def30c: issue6528: implement _is_revision_affected_fast using callback
Summary

The delta comming from a bundle/stream does not exists in the revlog yet, so we
will need other way to retrieve the same information.

To prepare for this we split the function to use callbacks in the core logic.

Diff Detail

Repository
rHG Mercurial
Branch
stable
Lint
No Linters Available
Unit
No Unit Test Coverage

Event Timeline

marmoute created this revision.Aug 7 2021, 10:07 AM
baymax updated this revision to Diff 29859.Aug 8 2021, 5:22 AM

✅ refresh by Heptapod after a successful CI run (🐙 💚)
⚠ This patch is intended for stable ⚠

pulkit accepted this revision.Aug 10 2021, 8:18 AM
This revision is now accepted and ready to land.Aug 10 2021, 8:18 AM

Revision Contents
Changeset List

PathPackages
Mmercurial/revlogutils/rewrite.py (50 lines)

Diff 29847

mercurial/revlogutils/rewrite.py

if has_meta: if has_meta:
(p1, p2) = parents_revs() (p1, p2) = parents_revs()
if p1 != nullrev and p2 == nullrev: if p1 != nullrev and p2 == nullrev:
return True return True
return False return False
def _is_revision_affected_fast(repo, fl, filerev, metadata_cache): def _is_revision_affected_fast(repo, fl, filerev, metadata_cache):
rl = fl._revlog
is_censored = lambda: rl.iscensored(filerev)
delta_base = lambda: rl.deltaparent(filerev)
delta = lambda: rl._chunk(filerev)
full_text = lambda: rl.rawdata(filerev)
parent_revs = lambda: rl.parentrevs(filerev)
return _is_revision_affected_fast_inner(
is_censored,
delta_base,
delta,
full_text,
parent_revs,
filerev,
metadata_cache,
)
def _is_revision_affected_fast_inner(
is_censored,
delta_base,
delta,
full_text,
parent_revs,
filerev,
metadata_cache,
):
"""Optimization fast-path for `_is_revision_affected`. """Optimization fast-path for `_is_revision_affected`.
`metadata_cache` is a dict of `{rev: has_metadata}` which allows any `metadata_cache` is a dict of `{rev: has_metadata}` which allows any
revision to check if its base has metadata, saving computation of the full revision to check if its base has metadata, saving computation of the full
text, instead looking at the current delta. text, instead looking at the current delta.
This optimization only works if the revisions are looked at in order.""" This optimization only works if the revisions are looked at in order."""
rl = fl._revlog
if rl.iscensored(filerev): if is_censored():
# Censored revisions don't contain metadata, so they cannot be affected # Censored revisions don't contain metadata, so they cannot be affected
metadata_cache[filerev] = False metadata_cache[filerev] = False
return False return False
p1, p2 = rl.parentrevs(filerev) p1, p2 = parent_revs()
if p1 == nullrev or p2 != nullrev: if p1 == nullrev or p2 != nullrev:
return False return False
delta_parent = rl.deltaparent(filerev) delta_parent = delta_base()
parent_has_metadata = metadata_cache.get(delta_parent) parent_has_metadata = metadata_cache.get(delta_parent)
if parent_has_metadata is None: if parent_has_metadata is None:
is_affected = _is_revision_affected(fl, filerev, metadata_cache) return _is_revision_affected_inner(
return is_affected full_text,
parent_revs,
filerev,
metadata_cache,
)
chunk = rl._chunk(filerev) chunk = delta()
if not len(chunk): if not len(chunk):
# No diff for this revision # No diff for this revision
return parent_has_metadata return parent_has_metadata
header_length = 12 header_length = 12
if len(chunk) < header_length: if len(chunk) < header_length:
raise error.Abort(_(b"patch cannot be decoded")) raise error.Abort(_(b"patch cannot be decoded"))
start, _end, _length = struct.unpack(b">lll", chunk[:header_length]) start, _end, _length = struct.unpack(b">lll", chunk[:header_length])
if start < 2: # len(b'\x01\n') == 2 if start < 2: # len(b'\x01\n') == 2
# This delta does *something* to the metadata marker (if any). # This delta does *something* to the metadata marker (if any).
# Check it the slow way # Check it the slow way
is_affected = _is_revision_affected(fl, filerev, metadata_cache) is_affected = _is_revision_affected_inner(
full_text,
parent_revs,
filerev,
metadata_cache,
)
return is_affected return is_affected
# The diff did not remove or add the metadata header, it's then in the same # The diff did not remove or add the metadata header, it's then in the same
# situation as its parent # situation as its parent
metadata_cache[filerev] = parent_has_metadata metadata_cache[filerev] = parent_has_metadata
return parent_has_metadata return parent_has_metadata