exchange: improve computation of relevant markers for large repos
Compute the candidate nodes with relevant markers directly
from keys of the predecessors/successors/children dictionaries of
obsstore. This is faster than iterating over all nodes directly.
This test could be further improved for repositories with relative
few markers compared to the repository size, but this is no longer
hot already. With the current loop structure, the obshashrange use
works as well as before as it passes lists with a single node.
Adjust the interface by allowing revision lists as well as node lists.
This helps cases that computes ancestors as it reduces the
materialisation cost. Use this in _pushdiscoveryobsmarker and
_getbundleobsmarkerpart. Improve the latter further by directly using
ancestors().
Performance benchmarks show notable and welcome improvement to no-op push and
pull (that would also apply to other push/pull). This apply to push and pull
done without evolve.
### push/pull Benchmark parameter
# bin-env-vars.hg.flavor = default
# benchmark.variants.explicit-rev = none
# benchmark.variants.protocol = ssh
# benchmark.variants.revs = none
## benchmark.name = hg.command.pull
# data-env-vars.name = mercurial-devel-2024-03-22-zstd-sparse-revlog
before: 5.968537 seconds
after: 5.668507 seconds (-5.03%, -0.30)
# data-env-vars.name = tryton-devel-2024-03-22-zstd-sparse-revlog
before: 1.446232 seconds
after: 0.835553 seconds (-42.23%, -0.61)
# data-env-vars.name = netbsd-src-draft-2024-09-19-zstd-sparse-revlog
before: 5.777412 seconds
after: 2.523454 seconds (-56.32%, -3.25)
## benchmark.name = hg.command.push
# data-env-vars.name = mercurial-devel-2024-03-22-zstd-sparse-revlog
before: 6.155501 seconds
after: 5.885072 seconds (-4.39%, -0.27)
# data-env-vars.name = tryton-devel-2024-03-22-zstd-sparse-revlog
before: 1.491054 seconds
after: 0.934882 seconds (-37.30%, -0.56)
# data-env-vars.name = netbsd-src-draft-2024-09-19-zstd-sparse-revlog
before: 5.902494 seconds
after: 2.957644 seconds (-49.89%, -2.94)
There is not notable different in these result using the "rust" flavor instead
of the "default". The performance impact on the same operation when using
evolve were also tested and no impact was noted.
# similar.py - mechanisms for finding similar files
#
# Copyright 2005-2007 Olivia Mackall <olivia@selenic.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from __future__ import annotations
from .i18n import _
from . import (
mdiff,
)
def _findexactmatches(repo, added, removed):
"""find renamed files that have no changes
Takes a list of new filectxs and a list of removed filectxs, and yields
(before, after) tuples of exact matches.
"""
# Build table of removed files: {hash(fctx.data()): [fctx, ...]}.
# We use hash() to discard fctx.data() from memory.
hashes = {}
progress = repo.ui.makeprogress(
_(b'searching for exact renames'),
total=(len(added) + len(removed)),
unit=_(b'files'),
)
for fctx in removed:
progress.increment()
h = hash(fctx.data())
if h not in hashes:
hashes[h] = [fctx]
else:
hashes[h].append(fctx)
# For each added file, see if it corresponds to a removed file.
for fctx in added:
progress.increment()
adata = fctx.data()
h = hash(adata)
for rfctx in hashes.get(h, []):
# compare between actual file contents for exact identity
if adata == rfctx.data():
yield (rfctx, fctx)
break
# Done
progress.complete()
def _ctxdata(fctx):
# lazily load text
orig = fctx.data()
return orig, mdiff.splitnewlines(orig)
def _score(fctx, otherdata):
orig, lines = otherdata
text = fctx.data()
# mdiff.blocks() returns blocks of matching lines
# count the number of bytes in each
equal = 0
matches = mdiff.blocks(text, orig)
for x1, x2, y1, y2 in matches:
for line in lines[y1:y2]:
equal += len(line)
lengths = len(text) + len(orig)
return equal * 2.0 / lengths
def score(fctx1, fctx2):
return _score(fctx1, _ctxdata(fctx2))
def _findsimilarmatches(repo, added, removed, threshold):
"""find potentially renamed files based on similar file content
Takes a list of new filectxs and a list of removed filectxs, and yields
(before, after, score) tuples of partial matches.
"""
copies = {}
progress = repo.ui.makeprogress(
_(b'searching for similar files'), unit=_(b'files'), total=len(removed)
)
for r in removed:
progress.increment()
data = None
for a in added:
bestscore = copies.get(a, (None, threshold))[1]
if data is None:
data = _ctxdata(r)
myscore = _score(a, data)
if myscore > bestscore:
copies[a] = (r, myscore)
progress.complete()
for dest, v in copies.items():
source, bscore = v
yield source, dest, bscore
def _dropempty(fctxs):
return [x for x in fctxs if x.size() > 0]
def findrenames(repo, added, removed, threshold):
'''find renamed files -- yields (before, after, score) tuples'''
wctx = repo[None]
pctx = wctx.p1()
# Zero length files will be frequently unrelated to each other, and
# tracking the deletion/addition of such a file will probably cause more
# harm than good. We strip them out here to avoid matching them later on.
addedfiles = _dropempty(wctx[fp] for fp in sorted(added))
removedfiles = _dropempty(pctx[fp] for fp in sorted(removed) if fp in pctx)
# Find exact matches.
matchedfiles = set()
for a, b in _findexactmatches(repo, addedfiles, removedfiles):
matchedfiles.add(b)
yield (a.path(), b.path(), 1.0)
# If the user requested similar files to be matched, search for them also.
if threshold < 1.0:
addedfiles = [x for x in addedfiles if x not in matchedfiles]
for a, b, score in _findsimilarmatches(
repo, addedfiles, removedfiles, threshold
):
yield (a.path(), b.path(), score)