Mercurial > hg
view hgext/relink.py @ 20182:04036798ebed
branches: avoid unnecessary changectx.branch() calls
This requires reading from the changelog, which can be costly over NFS.
Note that this does not totally remove reading from the changelog; we
still do that when calling changectx.closesbranch(). That call will be
removed in a later patch.
Running hg branches on the PyPy repo (with 996) over a busy NFS server,
before this change:
$ time hg --profile branches > /dev/null
CallCount Recursive Total(s) Inline(s) module:lineno(function)
2042 0 2.2827 2.2827 <open>
2036 0 0.9840 0.9840 <method 'close' of 'file' objects>
2036 0 0.0464 0.0464 <method 'read' of 'file' objects>
5233 0 0.1985 0.0453 mercurial.repoview:161(changelog)
10462 0 0.0791 0.0314 mercurial.changelog:133(tip)
5233 0 0.0388 0.0176 mercurial.localrepo:26(__get__)
10462 0 0.0250 0.0126 <len>
5233 0 0.0059 0.0039 mercurial.repoview:112(filterrevs)
10462 0 0.0029 0.0029 <hash>
2034 0 0.0444 0.0444 <method 'seek' of 'file' objects>
5340 0 0.0390 0.0390 mercurial.revlog:296(rev)
2582 0 0.0371 0.0371 <zlib.decompress>
3155 0 0.1963 0.0366 mercurial.context:202(__init__)
3155 0 0.1238 0.0306 mercurial.repoview:161(changelog)
3155 0 0.0261 0.0080 mercurial.changelog:183(rev)
9465 0 0.0061 0.0061 <isinstance>
1096 0 0.0023 0.0023 <binascii.unhexlify>
4251 0 0.0014 0.0014 <len>
2059 0 3.7341 0.0332 mercurial.changelog:270(read)
2059 0 3.6304 0.0307 mercurial.revlog:907(revision)
2057 0 0.0262 0.0137 mercurial.changelog:28(decodeextra)
4118 0 0.0094 0.0094 <method 'split' of 'str' objects>
4118 0 0.0270 0.0048 mercurial.encoding:61(tolocal)
2059 0 0.0040 0.0040 <method 'index' of 'str' objects>
10462 0 0.0791 0.0314 mercurial.changelog:133(tip)
10462 0 0.0289 0.0207 mercurial.changelog:190(node)
10462 0 0.0188 0.0091 <len>
52433 20932 0.0478 0.0310 <len>
20932 0 0.0221 0.0168 mercurial.revlog:262(__len__)
2059 0 3.6304 0.0307 mercurial.revlog:907(revision)
real 0m4.361s
user 0m0.986s
sys 0m0.237s
After this change:
$ time hg --profile branches > /dev/null
CallCount Recursive Total(s) Inline(s) module:lineno(function)
1069 0 1.1098 1.1098 <open>
1063 0 0.4865 0.4865 <method 'close' of 'file' objects>
4122 0 0.1811 0.0404 mercurial.repoview:161(changelog)
8240 0 0.0712 0.0272 mercurial.changelog:133(tip)
4122 0 0.0378 0.0177 mercurial.localrepo:26(__get__)
8240 0 0.0221 0.0115 <len>
4122 0 0.0057 0.0033 mercurial.repoview:112(filterrevs)
8240 0 0.0025 0.0025 <hash>
3029 0 0.1979 0.0371 mercurial.context:202(__init__)
3029 0 0.1278 0.0310 mercurial.repoview:161(changelog)
3029 0 0.0230 0.0081 mercurial.changelog:183(rev)
9087 0 0.0061 0.0061 <isinstance>
1096 0 0.0026 0.0026 <binascii.unhexlify>
4125 0 0.0014 0.0014 <len>
4229 0 0.0337 0.0337 mercurial.revlog:296(rev)
1061 0 0.0296 0.0296 <method 'seek' of 'file' objects>
1063 0 0.0292 0.0292 <method 'read' of 'file' objects>
8240 0 0.0712 0.0272 mercurial.changelog:133(tip)
8240 0 0.0271 0.0196 mercurial.changelog:190(node)
8240 0 0.0169 0.0083 <len>
40476 16488 0.0422 0.0271 <len>
16488 0 0.0193 0.0152 mercurial.revlog:262(__len__)
1342 0 0.0241 0.0241 <zlib.decompress>
9445 0 0.0336 0.0224 mercurial.changelog:190(node)
9445 0 0.0112 0.0112 mercurial.revlog:317(node)
1074 0 1.9102 0.0224 mercurial.changelog:270(read)
1074 0 1.8397 0.0202 mercurial.revlog:907(revision)
1073 0 0.0187 0.0099 mercurial.changelog:28(decodeextra)
2148 0 0.0061 0.0061 <method 'split' of 'str' objects>
2148 0 0.0184 0.0034 mercurial.encoding:61(tolocal)
real 0m2.402s
user 0m0.735s
sys 0m0.177s
author | Brodie Rao <brodie@sf.io> |
---|---|
date | Fri, 15 Nov 2013 23:18:08 -0500 |
parents | c69e5911888d |
children | da0eb4970913 |
line wrap: on
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# Mercurial extension to provide 'hg relink' command # # Copyright (C) 2007 Brendan Cully <brendan@kublai.com> # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. """recreates hardlinks between repository clones""" from mercurial import hg, util from mercurial.i18n import _ import os, stat testedwith = 'internal' def relink(ui, repo, origin=None, **opts): """recreate hardlinks between two repositories When repositories are cloned locally, their data files will be hardlinked so that they only use the space of a single repository. Unfortunately, subsequent pulls into either repository will break hardlinks for any files touched by the new changesets, even if both repositories end up pulling the same changes. Similarly, passing --rev to "hg clone" will fail to use any hardlinks, falling back to a complete copy of the source repository. This command lets you recreate those hardlinks and reclaim that wasted space. This repository will be relinked to share space with ORIGIN, which must be on the same local disk. If ORIGIN is omitted, looks for "default-relink", then "default", in [paths]. Do not attempt any read operations on this repository while the command is running. (Both repositories will be locked against writes.) """ if (not util.safehasattr(util, 'samefile') or not util.safehasattr(util, 'samedevice')): raise util.Abort(_('hardlinks are not supported on this system')) src = hg.repository(repo.baseui, ui.expandpath(origin or 'default-relink', origin or 'default')) ui.status(_('relinking %s to %s\n') % (src.store.path, repo.store.path)) if repo.root == src.root: ui.status(_('there is nothing to relink\n')) return if not util.samedevice(src.store.path, repo.store.path): # No point in continuing raise util.Abort(_('source and destination are on different devices')) locallock = repo.lock() try: remotelock = src.lock() try: candidates = sorted(collect(src, ui)) targets = prune(candidates, src.store.path, repo.store.path, ui) do_relink(src.store.path, repo.store.path, targets, ui) finally: remotelock.release() finally: locallock.release() def collect(src, ui): seplen = len(os.path.sep) candidates = [] live = len(src['tip'].manifest()) # Your average repository has some files which were deleted before # the tip revision. We account for that by assuming that there are # 3 tracked files for every 2 live files as of the tip version of # the repository. # # mozilla-central as of 2010-06-10 had a ratio of just over 7:5. total = live * 3 // 2 src = src.store.path pos = 0 ui.status(_("tip has %d files, estimated total number of files: %s\n") % (live, total)) for dirpath, dirnames, filenames in os.walk(src): dirnames.sort() relpath = dirpath[len(src) + seplen:] for filename in sorted(filenames): if filename[-2:] not in ('.d', '.i'): continue st = os.stat(os.path.join(dirpath, filename)) if not stat.S_ISREG(st.st_mode): continue pos += 1 candidates.append((os.path.join(relpath, filename), st)) ui.progress(_('collecting'), pos, filename, _('files'), total) ui.progress(_('collecting'), None) ui.status(_('collected %d candidate storage files\n') % len(candidates)) return candidates def prune(candidates, src, dst, ui): def linkfilter(src, dst, st): try: ts = os.stat(dst) except OSError: # Destination doesn't have this file? return False if util.samefile(src, dst): return False if not util.samedevice(src, dst): # No point in continuing raise util.Abort( _('source and destination are on different devices')) if st.st_size != ts.st_size: return False return st targets = [] total = len(candidates) pos = 0 for fn, st in candidates: pos += 1 srcpath = os.path.join(src, fn) tgt = os.path.join(dst, fn) ts = linkfilter(srcpath, tgt, st) if not ts: ui.debug('not linkable: %s\n' % fn) continue targets.append((fn, ts.st_size)) ui.progress(_('pruning'), pos, fn, _('files'), total) ui.progress(_('pruning'), None) ui.status(_('pruned down to %d probably relinkable files\n') % len(targets)) return targets def do_relink(src, dst, files, ui): def relinkfile(src, dst): bak = dst + '.bak' os.rename(dst, bak) try: util.oslink(src, dst) except OSError: os.rename(bak, dst) raise os.remove(bak) CHUNKLEN = 65536 relinked = 0 savedbytes = 0 pos = 0 total = len(files) for f, sz in files: pos += 1 source = os.path.join(src, f) tgt = os.path.join(dst, f) # Binary mode, so that read() works correctly, especially on Windows sfp = file(source, 'rb') dfp = file(tgt, 'rb') sin = sfp.read(CHUNKLEN) while sin: din = dfp.read(CHUNKLEN) if sin != din: break sin = sfp.read(CHUNKLEN) sfp.close() dfp.close() if sin: ui.debug('not linkable: %s\n' % f) continue try: relinkfile(source, tgt) ui.progress(_('relinking'), pos, f, _('files'), total) relinked += 1 savedbytes += sz except OSError, inst: ui.warn('%s: %s\n' % (tgt, str(inst))) ui.progress(_('relinking'), None) ui.status(_('relinked %d files (%s reclaimed)\n') % (relinked, util.bytecount(savedbytes))) cmdtable = { 'relink': ( relink, [], _('[ORIGIN]') ) }