Mercurial > hg
view mercurial/grep.py @ 49622:dcb2581e33be stable
memory-usage: fix `hg log --follow --rev R F` space complexity
When running `hg log --follow --rev REVS FILES`, the log code will walk the
history of all FILES starting from the file revisions that exists in each REVS.
Before doing so, it looks if the files actually exists in the target revisions.
To do so, it opens the manifest of each revision in REVS to look up if we find
the associated items in FILES.
Before this changeset this was done in a way that created a changectx for
each target revision, keeping them in memory while we look into each file.
If the set of REVS is large, this means keeping the manifest for each entry in
REVS in memory. That can be largeā¦ if REV is in the form `::X`, this can quickly
become huge and saturate the memory. We have seen usage allocating 2GB per
second until memory runs out.
So this changeset invert the two loop so that only one revision is kept in
memory during the operation. This solve the memory explosion issue.
author | Pierre-Yves David <pierre-yves.david@octobus.net> |
---|---|
date | Sat, 19 Nov 2022 01:35:01 +0100 |
parents | 2e726c934fcd |
children | f4733654f144 |
line wrap: on
line source
# 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))