Mercurial > hg
view mercurial/bundlerepo.py @ 30212:260af19891f2
changegroup: increase write buffer size to 128k
By default, Python defers to the operating system for choosing the
default buffer size on opened files. On my Linux machine, the default
is 4k, which is really small for 2016.
This patch bumps the write buffer size when writing
changegroups/bundles to 128k. This matches the 128k read buffer
we already use on revlogs.
It's worth noting that this only impacts when writing to an explicit
file (such as during `hg bundle`). Buffers when writing to bundle
files via the repo vfs or to a temporary file are not impacted.
When producing a none-v2 bundle file of the mozilla-unified repository,
this change caused the number of write() system calls to drop from
952,449 to 29,788. After this change, the most frequent system
calls are fstat(), read(), lseek(), and open(). There were
2,523,672 system calls after this patch (so a net decrease of
~950k is statistically significant).
This change shows no performance change on my system. But I have a
high-end system with a fast SSD. It is quite possible this change
will have a significant impact on network file systems, where
extra network round trips due to excessive I/O system calls could
introduce significant latency.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Sun, 16 Oct 2016 13:35:23 -0700 |
parents | 1619efcde9a4 |
children | 1767723f71cf |
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# bundlerepo.py - repository class for viewing uncompressed bundles # # Copyright 2006, 2007 Benoit Boissinot <bboissin@gmail.com> # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. """Repository class for viewing uncompressed bundles. This provides a read-only repository interface to bundles as if they were part of the actual repository. """ from __future__ import absolute_import import os import shutil import tempfile from .i18n import _ from .node import nullid from . import ( bundle2, changegroup, changelog, cmdutil, discovery, error, exchange, filelog, localrepo, manifest, mdiff, node as nodemod, pathutil, phases, revlog, scmutil, util, ) class bundlerevlog(revlog.revlog): def __init__(self, opener, indexfile, bundle, linkmapper): # How it works: # To retrieve a revision, we need to know the offset of the revision in # the bundle (an unbundle object). We store this offset in the index # (start). The base of the delta is stored in the base field. # # To differentiate a rev in the bundle from a rev in the revlog, we # check revision against repotiprev. opener = scmutil.readonlyvfs(opener) revlog.revlog.__init__(self, opener, indexfile) self.bundle = bundle n = len(self) self.repotiprev = n - 1 chain = None self.bundlerevs = set() # used by 'bundle()' revset expression getchunk = lambda: bundle.deltachunk(chain) for chunkdata in iter(getchunk, {}): node = chunkdata['node'] p1 = chunkdata['p1'] p2 = chunkdata['p2'] cs = chunkdata['cs'] deltabase = chunkdata['deltabase'] delta = chunkdata['delta'] size = len(delta) start = bundle.tell() - size link = linkmapper(cs) if node in self.nodemap: # this can happen if two branches make the same change chain = node self.bundlerevs.add(self.nodemap[node]) continue for p in (p1, p2): if p not in self.nodemap: raise error.LookupError(p, self.indexfile, _("unknown parent")) if deltabase not in self.nodemap: raise LookupError(deltabase, self.indexfile, _('unknown delta base')) baserev = self.rev(deltabase) # start, size, full unc. size, base (unused), link, p1, p2, node e = (revlog.offset_type(start, 0), size, -1, baserev, link, self.rev(p1), self.rev(p2), node) self.index.insert(-1, e) self.nodemap[node] = n self.bundlerevs.add(n) chain = node n += 1 def _chunk(self, rev): # Warning: in case of bundle, the diff is against what we stored as # delta base, not against rev - 1 # XXX: could use some caching if rev <= self.repotiprev: return revlog.revlog._chunk(self, rev) self.bundle.seek(self.start(rev)) return self.bundle.read(self.length(rev)) def revdiff(self, rev1, rev2): """return or calculate a delta between two revisions""" if rev1 > self.repotiprev and rev2 > self.repotiprev: # hot path for bundle revb = self.index[rev2][3] if revb == rev1: return self._chunk(rev2) elif rev1 <= self.repotiprev and rev2 <= self.repotiprev: return revlog.revlog.revdiff(self, rev1, rev2) return mdiff.textdiff(self.revision(self.node(rev1)), self.revision(self.node(rev2))) def revision(self, nodeorrev): """return an uncompressed revision of a given node or revision number. """ if isinstance(nodeorrev, int): rev = nodeorrev node = self.node(rev) else: node = nodeorrev rev = self.rev(node) if node == nullid: return "" text = None chain = [] iterrev = rev # reconstruct the revision if it is from a changegroup while iterrev > self.repotiprev: if self._cache and self._cache[1] == iterrev: text = self._cache[2] break chain.append(iterrev) iterrev = self.index[iterrev][3] if text is None: text = self.baserevision(iterrev) while chain: delta = self._chunk(chain.pop()) text = mdiff.patches(text, [delta]) self._checkhash(text, node, rev) self._cache = (node, rev, text) return text def baserevision(self, nodeorrev): # Revlog subclasses may override 'revision' method to modify format of # content retrieved from revlog. To use bundlerevlog with such class one # needs to override 'baserevision' and make more specific call here. return revlog.revlog.revision(self, nodeorrev) def addrevision(self, text, transaction, link, p1=None, p2=None, d=None): raise NotImplementedError def addgroup(self, revs, linkmapper, transaction): raise NotImplementedError def strip(self, rev, minlink): raise NotImplementedError def checksize(self): raise NotImplementedError class bundlechangelog(bundlerevlog, changelog.changelog): def __init__(self, opener, bundle): changelog.changelog.__init__(self, opener) linkmapper = lambda x: x bundlerevlog.__init__(self, opener, self.indexfile, bundle, linkmapper) def baserevision(self, nodeorrev): # Although changelog doesn't override 'revision' method, some extensions # may replace this class with another that does. Same story with # manifest and filelog classes. # This bypasses filtering on changelog.node() and rev() because we need # revision text of the bundle base even if it is hidden. oldfilter = self.filteredrevs try: self.filteredrevs = () return changelog.changelog.revision(self, nodeorrev) finally: self.filteredrevs = oldfilter class bundlemanifest(bundlerevlog, manifest.manifest): def __init__(self, opener, bundle, linkmapper, dirlogstarts=None, dir=''): manifest.manifest.__init__(self, opener, dir=dir) bundlerevlog.__init__(self, opener, self.indexfile, bundle, linkmapper) if dirlogstarts is None: dirlogstarts = {} if self.bundle.version == "03": dirlogstarts = _getfilestarts(self.bundle) self._dirlogstarts = dirlogstarts self._linkmapper = linkmapper def baserevision(self, nodeorrev): node = nodeorrev if isinstance(node, int): node = self.node(node) if node in self.fulltextcache: result = self.fulltextcache[node].tostring() else: result = manifest.manifest.revision(self, nodeorrev) return result def dirlog(self, d): if d in self._dirlogstarts: self.bundle.seek(self._dirlogstarts[d]) return bundlemanifest( self.opener, self.bundle, self._linkmapper, self._dirlogstarts, dir=d) return super(bundlemanifest, self).dirlog(d) class bundlefilelog(bundlerevlog, filelog.filelog): def __init__(self, opener, path, bundle, linkmapper): filelog.filelog.__init__(self, opener, path) bundlerevlog.__init__(self, opener, self.indexfile, bundle, linkmapper) def baserevision(self, nodeorrev): return filelog.filelog.revision(self, nodeorrev) class bundlepeer(localrepo.localpeer): def canpush(self): return False class bundlephasecache(phases.phasecache): def __init__(self, *args, **kwargs): super(bundlephasecache, self).__init__(*args, **kwargs) if util.safehasattr(self, 'opener'): self.opener = scmutil.readonlyvfs(self.opener) def write(self): raise NotImplementedError def _write(self, fp): raise NotImplementedError def _updateroots(self, phase, newroots, tr): self.phaseroots[phase] = newroots self.invalidate() self.dirty = True def _getfilestarts(bundle): bundlefilespos = {} for chunkdata in iter(bundle.filelogheader, {}): fname = chunkdata['filename'] bundlefilespos[fname] = bundle.tell() for chunk in iter(lambda: bundle.deltachunk(None), {}): pass return bundlefilespos class bundlerepository(localrepo.localrepository): def __init__(self, ui, path, bundlename): def _writetempbundle(read, suffix, header=''): """Write a temporary file to disk This is closure because we need to make sure this tracked by self.tempfile for cleanup purposes.""" fdtemp, temp = self.vfs.mkstemp(prefix="hg-bundle-", suffix=".hg10un") self.tempfile = temp with os.fdopen(fdtemp, 'wb') as fptemp: fptemp.write(header) while True: chunk = read(2**18) if not chunk: break fptemp.write(chunk) return self.vfs.open(self.tempfile, mode="rb") self._tempparent = None try: localrepo.localrepository.__init__(self, ui, path) except error.RepoError: self._tempparent = tempfile.mkdtemp() localrepo.instance(ui, self._tempparent, 1) localrepo.localrepository.__init__(self, ui, self._tempparent) self.ui.setconfig('phases', 'publish', False, 'bundlerepo') if path: self._url = 'bundle:' + util.expandpath(path) + '+' + bundlename else: self._url = 'bundle:' + bundlename self.tempfile = None f = util.posixfile(bundlename, "rb") self.bundlefile = self.bundle = exchange.readbundle(ui, f, bundlename) if isinstance(self.bundle, bundle2.unbundle20): cgstream = None for part in self.bundle.iterparts(): if part.type == 'changegroup': if cgstream is not None: raise NotImplementedError("can't process " "multiple changegroups") cgstream = part version = part.params.get('version', '01') legalcgvers = changegroup.supportedincomingversions(self) if version not in legalcgvers: msg = _('Unsupported changegroup version: %s') raise error.Abort(msg % version) if self.bundle.compressed(): cgstream = _writetempbundle(part.read, ".cg%sun" % version) if cgstream is None: raise error.Abort(_('No changegroups found')) cgstream.seek(0) self.bundle = changegroup.getunbundler(version, cgstream, 'UN') elif self.bundle.compressed(): f = _writetempbundle(self.bundle.read, '.hg10un', header='HG10UN') self.bundlefile = self.bundle = exchange.readbundle(ui, f, bundlename, self.vfs) # dict with the mapping 'filename' -> position in the bundle self.bundlefilespos = {} self.firstnewrev = self.changelog.repotiprev + 1 phases.retractboundary(self, None, phases.draft, [ctx.node() for ctx in self[self.firstnewrev:]]) @localrepo.unfilteredpropertycache def _phasecache(self): return bundlephasecache(self, self._phasedefaults) @localrepo.unfilteredpropertycache def changelog(self): # consume the header if it exists self.bundle.changelogheader() c = bundlechangelog(self.svfs, self.bundle) self.manstart = self.bundle.tell() return c @localrepo.unfilteredpropertycache def manifest(self): self.bundle.seek(self.manstart) # consume the header if it exists self.bundle.manifestheader() linkmapper = self.unfiltered().changelog.rev m = bundlemanifest(self.svfs, self.bundle, linkmapper) self.filestart = self.bundle.tell() return m @localrepo.unfilteredpropertycache def manstart(self): self.changelog return self.manstart @localrepo.unfilteredpropertycache def filestart(self): self.manifest return self.filestart def url(self): return self._url def file(self, f): if not self.bundlefilespos: self.bundle.seek(self.filestart) self.bundlefilespos = _getfilestarts(self.bundle) if f in self.bundlefilespos: self.bundle.seek(self.bundlefilespos[f]) linkmapper = self.unfiltered().changelog.rev return bundlefilelog(self.svfs, f, self.bundle, linkmapper) else: return filelog.filelog(self.svfs, f) def close(self): """Close assigned bundle file immediately.""" self.bundlefile.close() if self.tempfile is not None: self.vfs.unlink(self.tempfile) if self._tempparent: shutil.rmtree(self._tempparent, True) def cancopy(self): return False def peer(self): return bundlepeer(self) def getcwd(self): return os.getcwd() # always outside the repo # Check if parents exist in localrepo before setting def setparents(self, p1, p2=nullid): p1rev = self.changelog.rev(p1) p2rev = self.changelog.rev(p2) msg = _("setting parent to node %s that only exists in the bundle\n") if self.changelog.repotiprev < p1rev: self.ui.warn(msg % nodemod.hex(p1)) if self.changelog.repotiprev < p2rev: self.ui.warn(msg % nodemod.hex(p2)) return super(bundlerepository, self).setparents(p1, p2) def instance(ui, path, create): if create: raise error.Abort(_('cannot create new bundle repository')) # internal config: bundle.mainreporoot parentpath = ui.config("bundle", "mainreporoot", "") if not parentpath: # try to find the correct path to the working directory repo parentpath = cmdutil.findrepo(os.getcwd()) if parentpath is None: parentpath = '' if parentpath: # Try to make the full path relative so we get a nice, short URL. # In particular, we don't want temp dir names in test outputs. cwd = os.getcwd() if parentpath == cwd: parentpath = '' else: cwd = pathutil.normasprefix(cwd) if parentpath.startswith(cwd): parentpath = parentpath[len(cwd):] u = util.url(path) path = u.localpath() if u.scheme == 'bundle': s = path.split("+", 1) if len(s) == 1: repopath, bundlename = parentpath, s[0] else: repopath, bundlename = s else: repopath, bundlename = parentpath, path return bundlerepository(ui, repopath, bundlename) class bundletransactionmanager(object): def transaction(self): return None def close(self): raise NotImplementedError def release(self): raise NotImplementedError def getremotechanges(ui, repo, other, onlyheads=None, bundlename=None, force=False): '''obtains a bundle of changes incoming from other "onlyheads" restricts the returned changes to those reachable from the specified heads. "bundlename", if given, stores the bundle to this file path permanently; otherwise it's stored to a temp file and gets deleted again when you call the returned "cleanupfn". "force" indicates whether to proceed on unrelated repos. Returns a tuple (local, csets, cleanupfn): "local" is a local repo from which to obtain the actual incoming changesets; it is a bundlerepo for the obtained bundle when the original "other" is remote. "csets" lists the incoming changeset node ids. "cleanupfn" must be called without arguments when you're done processing the changes; it closes both the original "other" and the one returned here. ''' tmp = discovery.findcommonincoming(repo, other, heads=onlyheads, force=force) common, incoming, rheads = tmp if not incoming: try: if bundlename: os.unlink(bundlename) except OSError: pass return repo, [], other.close commonset = set(common) rheads = [x for x in rheads if x not in commonset] bundle = None bundlerepo = None localrepo = other.local() if bundlename or not localrepo: # create a bundle (uncompressed if other repo is not local) # developer config: devel.legacy.exchange legexc = ui.configlist('devel', 'legacy.exchange') forcebundle1 = 'bundle2' not in legexc and 'bundle1' in legexc canbundle2 = (not forcebundle1 and other.capable('getbundle') and other.capable('bundle2')) if canbundle2: kwargs = {} kwargs['common'] = common kwargs['heads'] = rheads kwargs['bundlecaps'] = exchange.caps20to10(repo) kwargs['cg'] = True b2 = other.getbundle('incoming', **kwargs) fname = bundle = changegroup.writechunks(ui, b2._forwardchunks(), bundlename) else: if other.capable('getbundle'): cg = other.getbundle('incoming', common=common, heads=rheads) elif onlyheads is None and not other.capable('changegroupsubset'): # compat with older servers when pulling all remote heads cg = other.changegroup(incoming, "incoming") rheads = None else: cg = other.changegroupsubset(incoming, rheads, 'incoming') if localrepo: bundletype = "HG10BZ" else: bundletype = "HG10UN" fname = bundle = bundle2.writebundle(ui, cg, bundlename, bundletype) # keep written bundle? if bundlename: bundle = None if not localrepo: # use the created uncompressed bundlerepo localrepo = bundlerepo = bundlerepository(repo.baseui, repo.root, fname) # this repo contains local and other now, so filter out local again common = repo.heads() if localrepo: # Part of common may be remotely filtered # So use an unfiltered version # The discovery process probably need cleanup to avoid that localrepo = localrepo.unfiltered() csets = localrepo.changelog.findmissing(common, rheads) if bundlerepo: reponodes = [ctx.node() for ctx in bundlerepo[bundlerepo.firstnewrev:]] remotephases = other.listkeys('phases') pullop = exchange.pulloperation(bundlerepo, other, heads=reponodes) pullop.trmanager = bundletransactionmanager() exchange._pullapplyphases(pullop, remotephases) def cleanup(): if bundlerepo: bundlerepo.close() if bundle: os.unlink(bundle) other.close() return (localrepo, csets, cleanup)