phases: rework the logic of _pushdiscoveryphase to bound complexity
This rework the various graph traversal in _pushdiscoveryphase to keep the
complexity in check.
This is done though a couple of things:
- first, limiting the space we have to explore, for example, if we are not in
publishing push, we don't need to consider remote draft roots that are also
draft locally, as there is nothing to be moved there.
- avoid unbounded descendant computation, and use the faster "rev between"
computation.
This provide a massive boost to performance when exchanging with repository with
a massive amount of draft, like mozilla-try:
### data-env-vars.name = mozilla-try-2023-03-22-zstd-sparse-revlog
# benchmark.name = hg.command.push
# bin-env-vars.hg.flavor = default
# bin-env-vars.hg.py-re2-module = default
# benchmark.variants.explicit-rev = all-out-heads
# benchmark.variants.issue6528 = disabled
# benchmark.variants.protocol = ssh
# benchmark.variants.reuse-external-delta-parent = default
## benchmark.variants.revs = any-1-extra-rev
before: 20.346590 seconds
after: 11.232059 seconds (-38.15%, -7.48 seconds)
## benchmark.variants.revs = any-100-extra-rev
before: 24.752051 seconds
after: 15.367412 seconds (-37.91%, -9.38 seconds)
After this changes, the push operation is still quite too slow. Some of this
can be attributed to general phases slowness (reading all the roots from disk
for example) and other know slowness (not using persistent-nodemap, branchmap,
tags, etc. We are also working on them, but with this series, phase discovery
during push no longer showing up in profile and this is a pretty nice and bit
low-hanging fruit out of the way.
### (same case as the above)
# benchmark.variants.revs = any-1-extra-rev
pre-%ln-change: 44.235070
this-changeset: 11.232059 seconds (-74.61%, -33.00 seconds)
# benchmark.variants.revs = any-100-extra-rev
pre-%ln-change: 49.234697
this-changeset: 15.367412 seconds (-68.79%, -33.87 seconds)
Note that with this change, the `hg push` performance is now much closer to the
`hg pull` performance, even it still lagging behind a bit. (and the overall
performance are still too slow).
### data-env-vars.name = mozilla-try-2023-03-22-ds2-pnm
# benchmark.variants.explicit-rev = all-out-heads
# benchmark.variants.issue6528 = disabled
# benchmark.variants.protocol = ssh
# benchmark.variants.pulled-delta-reuse-policy = default
# bin-env-vars.hg.flavor = rust
## benchmark.variants.revs = any-1-extra-rev
hg.command.pull: 6.517450
hg.command.push: 11.219888
## benchmark.variants.revs = any-100-extra-rev
hg.command.pull: 10.160991
hg.command.push: 14.251107
### data-env-vars.name = mozilla-try-2023-03-22-zstd-sparse-revlog
# bin-env-vars.hg.py-re2-module = default
# benchmark.variants.explicit-rev = all-out-heads
# benchmark.variants.issue6528 = disabled
# benchmark.variants.protocol = ssh
# benchmark.variants.pulled-delta-reuse-policy = default
## bin-env-vars.hg.flavor = default
## benchmark.variants.revs = any-1-extra-rev
hg.command.pull: 8.577772
hg.command.push: 11.232059
## bin-env-vars.hg.flavor = default
## benchmark.variants.revs = any-100-extra-rev
hg.command.pull: 13.152976
hg.command.push: 15.367412
## bin-env-vars.hg.flavor = rust
## benchmark.variants.revs = any-1-extra-rev
hg.command.pull: 8.731982
hg.command.push: 11.178751
## bin-env-vars.hg.flavor = rust
## benchmark.variants.revs = any-100-extra-rev
hg.command.pull: 13.184236
hg.command.push: 15.620843
# grep.py - logic for history walk and grep
#
# 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.
import difflib
from .i18n import _
from . import (
error,
match as matchmod,
pycompat,
scmutil,
util,
)
def matchlines(body, regexp):
begin = 0
linenum = 0
while begin < len(body):
match = regexp.search(body, begin)
if not match:
break
mstart, mend = match.span()
linenum += body.count(b'\n', begin, mstart) + 1
lstart = body.rfind(b'\n', begin, mstart) + 1 or begin
begin = body.find(b'\n', mend) + 1 or len(body) + 1
lend = begin - 1
yield linenum, mstart - lstart, mend - lstart, body[lstart:lend]
class linestate:
def __init__(self, line, linenum, colstart, colend):
self.line = line
self.linenum = linenum
self.colstart = colstart
self.colend = colend
def __hash__(self):
return hash(self.line)
def __eq__(self, other):
return self.line == other.line
def findpos(self, regexp):
"""Iterate all (start, end) indices of matches"""
yield self.colstart, self.colend
p = self.colend
while p < len(self.line):
m = regexp.search(self.line, p)
if not m:
break
if m.end() == p:
p += 1
else:
yield m.span()
p = m.end()
def difflinestates(a, b):
sm = difflib.SequenceMatcher(None, a, b)
for tag, alo, ahi, blo, bhi in sm.get_opcodes():
if tag == 'insert':
for i in range(blo, bhi):
yield (b'+', b[i])
elif tag == 'delete':
for i in range(alo, ahi):
yield (b'-', a[i])
elif tag == 'replace':
for i in range(alo, ahi):
yield (b'-', a[i])
for i in range(blo, bhi):
yield (b'+', b[i])
class grepsearcher:
"""Search files and revisions for lines matching the given pattern
Options:
- all_files to search unchanged files at that revision.
- diff to search files in the parent revision so diffs can be generated.
- follow to skip files across copies and renames.
"""
def __init__(
self, ui, repo, regexp, all_files=False, diff=False, follow=False
):
self._ui = ui
self._repo = repo
self._regexp = regexp
self._all_files = all_files
self._diff = diff
self._follow = follow
self._getfile = util.lrucachefunc(repo.file)
self._getrenamed = scmutil.getrenamedfn(repo)
self._matches = {}
self._copies = {}
self._skip = set()
self._revfiles = {}
def skipfile(self, fn, rev):
"""Exclude the given file (and the copy at the specified revision)
from future search"""
copy = self._copies.get(rev, {}).get(fn)
self._skip.add(fn)
if copy:
self._skip.add(copy)
def searchfiles(self, revs, makefilematcher):
"""Walk files and revisions to yield (fn, ctx, pstates, states)
matches
states is a list of linestate objects. pstates may be empty unless
diff is True.
"""
for ctx in scmutil.walkchangerevs(
self._repo, revs, makefilematcher, self._prep
):
rev = ctx.rev()
parent = ctx.p1().rev()
for fn in sorted(self._revfiles.get(rev, [])):
states = self._matches[rev][fn]
copy = self._copies.get(rev, {}).get(fn)
if fn in self._skip:
if copy:
self._skip.add(copy)
continue
pstates = self._matches.get(parent, {}).get(copy or fn, [])
if pstates or states:
yield fn, ctx, pstates, states
del self._revfiles[rev]
# We will keep the matches dict for the duration of the window
# clear the matches dict once the window is over
if not self._revfiles:
self._matches.clear()
def _grepbody(self, fn, rev, body):
self._matches[rev].setdefault(fn, [])
m = self._matches[rev][fn]
if body is None:
return
for lnum, cstart, cend, line in matchlines(body, self._regexp):
s = linestate(line, lnum, cstart, cend)
m.append(s)
def _readfile(self, ctx, fn):
rev = ctx.rev()
if rev is None:
fctx = ctx[fn]
try:
return fctx.data()
except FileNotFoundError:
pass
else:
flog = self._getfile(fn)
fnode = ctx.filenode(fn)
try:
return flog.read(fnode)
except error.CensoredNodeError:
self._ui.warn(
_(
b'cannot search in censored file: '
b'%(filename)s:%(revnum)s\n'
)
% {b'filename': fn, b'revnum': pycompat.bytestr(rev)}
)
def _prep(self, ctx, fmatch):
rev = ctx.rev()
pctx = ctx.p1()
self._matches.setdefault(rev, {})
if self._diff:
parent = pctx.rev()
self._matches.setdefault(parent, {})
files = self._revfiles.setdefault(rev, [])
if rev is None:
# in `hg grep pattern`, 2/3 of the time is spent is spent in
# pathauditor checks without this in mozilla-central
contextmanager = self._repo.wvfs.audit.cached
else:
contextmanager = util.nullcontextmanager
with contextmanager():
# TODO: maybe better to warn missing files?
if self._all_files:
fmatch = matchmod.badmatch(fmatch, lambda f, msg: None)
filenames = ctx.matches(fmatch)
else:
filenames = (f for f in ctx.files() if fmatch(f))
for fn in filenames:
# fn might not exist in the revision (could be a file removed by
# the revision). We could check `fn not in ctx` even when rev is
# None, but it's less racy to protect againt that in readfile.
if rev is not None and fn not in ctx:
continue
copy = None
if self._follow:
copy = self._getrenamed(fn, rev)
if copy:
self._copies.setdefault(rev, {})[fn] = copy
if fn in self._skip:
self._skip.add(copy)
if fn in self._skip:
continue
files.append(fn)
if fn not in self._matches[rev]:
self._grepbody(fn, rev, self._readfile(ctx, fn))
if self._diff:
pfn = copy or fn
if pfn not in self._matches[parent] and pfn in pctx:
self._grepbody(pfn, parent, self._readfile(pctx, pfn))