Mercurial > hg
view hgext/convert/gnuarch.py @ 30817:2b279126b8f5
revlog: use compression engine APIs for decompression
Now that compression engines declare their header in revlog chunks
and can decompress revlog chunks, we refactor revlog.decompress()
to use them.
Making full use of the property that revlog compressor objects are
reusable, revlog instances now maintain a dict mapping an engine's
revlog header to a compressor object. This is not only a performance
optimization for engines where compressor object reuse can result in
better performance, but it also serves as a cache of header values
so we don't need to perform redundant lookups against the compression
engine manager. (Yes, I measured and the overhead of a function call
versus a dict lookup was observed.)
Replacing the previous inline lookup table with a dict lookup was
measured to make chunk reading ~2.5% slower on changelogs and ~4.5%
slower on manifests. So, the inline lookup table has been mostly
preserved so we don't lose performance. This is unfortunate. But
many decompression operations complete in microseconds, so Python
attribute lookup, dict lookup, and function calls do matter.
The impact of this change on mozilla-unified is as follows:
$ hg perfrevlogchunks -c
! chunk
! wall 1.953663 comb 1.950000 user 1.920000 sys 0.030000 (best of 6)
! wall 1.946000 comb 1.940000 user 1.910000 sys 0.030000 (best of 6)
! chunk batch
! wall 1.791075 comb 1.800000 user 1.760000 sys 0.040000 (best of 6)
! wall 1.785690 comb 1.770000 user 1.750000 sys 0.020000 (best of 6)
$ hg perfrevlogchunks -m
! chunk
! wall 2.587262 comb 2.580000 user 2.550000 sys 0.030000 (best of 4)
! wall 2.616330 comb 2.610000 user 2.560000 sys 0.050000 (best of 4)
! chunk batch
! wall 2.427092 comb 2.420000 user 2.400000 sys 0.020000 (best of 5)
! wall 2.462061 comb 2.460000 user 2.400000 sys 0.060000 (best of 4)
Changelog chunk reading is slightly faster but manifest reading is
slower. What gives?
On this repo, 99.85% of changelog entries are zlib compressed (the 'x'
header). On the manifest, 67.5% are zlib and 32.4% are '\0'. This patch
swapped the test order of 'x' and '\0' so now 'x' is tested first. This
makes changelogs faster since they almost always hit the first branch.
This makes a significant percentage of manifest '\0' chunks slower
because that code path now performs an extra test. Yes, I too can't
believe we're able to measure the impact of an if..elif with simple
string compares. I reckon this code would benefit from being written
in C...
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Fri, 13 Jan 2017 19:58:00 -0800 |
parents | a0939666b836 |
children | 671aba341d90 |
line wrap: on
line source
# gnuarch.py - GNU Arch support for the convert extension # # Copyright 2008, 2009 Aleix Conchillo Flaque <aleix@member.fsf.org> # and others # # 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 absolute_import import email import os import shutil import stat import tempfile from mercurial.i18n import _ from mercurial import ( encoding, error, util, ) from . import common class gnuarch_source(common.converter_source, common.commandline): class gnuarch_rev(object): def __init__(self, rev): self.rev = rev self.summary = '' self.date = None self.author = '' self.continuationof = None self.add_files = [] self.mod_files = [] self.del_files = [] self.ren_files = {} self.ren_dirs = {} def __init__(self, ui, path, revs=None): super(gnuarch_source, self).__init__(ui, path, revs=revs) if not os.path.exists(os.path.join(path, '{arch}')): raise common.NoRepo(_("%s does not look like a GNU Arch repository") % path) # Could use checktool, but we want to check for baz or tla. self.execmd = None if util.findexe('baz'): self.execmd = 'baz' else: if util.findexe('tla'): self.execmd = 'tla' else: raise error.Abort(_('cannot find a GNU Arch tool')) common.commandline.__init__(self, ui, self.execmd) self.path = os.path.realpath(path) self.tmppath = None self.treeversion = None self.lastrev = None self.changes = {} self.parents = {} self.tags = {} self.catlogparser = email.Parser.Parser() self.encoding = encoding.encoding self.archives = [] def before(self): # Get registered archives self.archives = [i.rstrip('\n') for i in self.runlines0('archives', '-n')] if self.execmd == 'tla': output = self.run0('tree-version', self.path) else: output = self.run0('tree-version', '-d', self.path) self.treeversion = output.strip() # Get name of temporary directory version = self.treeversion.split('/') self.tmppath = os.path.join(tempfile.gettempdir(), 'hg-%s' % version[1]) # Generate parents dictionary self.parents[None] = [] treeversion = self.treeversion child = None while treeversion: self.ui.status(_('analyzing tree version %s...\n') % treeversion) archive = treeversion.split('/')[0] if archive not in self.archives: self.ui.status(_('tree analysis stopped because it points to ' 'an unregistered archive %s...\n') % archive) break # Get the complete list of revisions for that tree version output, status = self.runlines('revisions', '-r', '-f', treeversion) self.checkexit(status, 'failed retrieving revisions for %s' % treeversion) # No new iteration unless a revision has a continuation-of header treeversion = None for l in output: rev = l.strip() self.changes[rev] = self.gnuarch_rev(rev) self.parents[rev] = [] # Read author, date and summary catlog, status = self.run('cat-log', '-d', self.path, rev) if status: catlog = self.run0('cat-archive-log', rev) self._parsecatlog(catlog, rev) # Populate the parents map self.parents[child].append(rev) # Keep track of the current revision as the child of the next # revision scanned child = rev # Check if we have to follow the usual incremental history # or if we have to 'jump' to a different treeversion given # by the continuation-of header. if self.changes[rev].continuationof: treeversion = '--'.join( self.changes[rev].continuationof.split('--')[:-1]) break # If we reached a base-0 revision w/o any continuation-of # header, it means the tree history ends here. if rev[-6:] == 'base-0': break def after(self): self.ui.debug('cleaning up %s\n' % self.tmppath) shutil.rmtree(self.tmppath, ignore_errors=True) def getheads(self): return self.parents[None] def getfile(self, name, rev): if rev != self.lastrev: raise error.Abort(_('internal calling inconsistency')) if not os.path.lexists(os.path.join(self.tmppath, name)): return None, None return self._getfile(name, rev) def getchanges(self, rev, full): if full: raise error.Abort(_("convert from arch does not support --full")) self._update(rev) changes = [] copies = {} for f in self.changes[rev].add_files: changes.append((f, rev)) for f in self.changes[rev].mod_files: changes.append((f, rev)) for f in self.changes[rev].del_files: changes.append((f, rev)) for src in self.changes[rev].ren_files: to = self.changes[rev].ren_files[src] changes.append((src, rev)) changes.append((to, rev)) copies[to] = src for src in self.changes[rev].ren_dirs: to = self.changes[rev].ren_dirs[src] chgs, cps = self._rendirchanges(src, to) changes += [(f, rev) for f in chgs] copies.update(cps) self.lastrev = rev return sorted(set(changes)), copies, set() def getcommit(self, rev): changes = self.changes[rev] return common.commit(author=changes.author, date=changes.date, desc=changes.summary, parents=self.parents[rev], rev=rev) def gettags(self): return self.tags def _execute(self, cmd, *args, **kwargs): cmdline = [self.execmd, cmd] cmdline += args cmdline = [util.shellquote(arg) for arg in cmdline] cmdline += ['>', os.devnull, '2>', os.devnull] cmdline = util.quotecommand(' '.join(cmdline)) self.ui.debug(cmdline, '\n') return os.system(cmdline) def _update(self, rev): self.ui.debug('applying revision %s...\n' % rev) changeset, status = self.runlines('replay', '-d', self.tmppath, rev) if status: # Something went wrong while merging (baz or tla # issue?), get latest revision and try from there shutil.rmtree(self.tmppath, ignore_errors=True) self._obtainrevision(rev) else: old_rev = self.parents[rev][0] self.ui.debug('computing changeset between %s and %s...\n' % (old_rev, rev)) self._parsechangeset(changeset, rev) def _getfile(self, name, rev): mode = os.lstat(os.path.join(self.tmppath, name)).st_mode if stat.S_ISLNK(mode): data = os.readlink(os.path.join(self.tmppath, name)) if mode: mode = 'l' else: mode = '' else: data = open(os.path.join(self.tmppath, name), 'rb').read() mode = (mode & 0o111) and 'x' or '' return data, mode def _exclude(self, name): exclude = ['{arch}', '.arch-ids', '.arch-inventory'] for exc in exclude: if name.find(exc) != -1: return True return False def _readcontents(self, path): files = [] contents = os.listdir(path) while len(contents) > 0: c = contents.pop() p = os.path.join(path, c) # os.walk could be used, but here we avoid internal GNU # Arch files and directories, thus saving a lot time. if not self._exclude(p): if os.path.isdir(p): contents += [os.path.join(c, f) for f in os.listdir(p)] else: files.append(c) return files def _rendirchanges(self, src, dest): changes = [] copies = {} files = self._readcontents(os.path.join(self.tmppath, dest)) for f in files: s = os.path.join(src, f) d = os.path.join(dest, f) changes.append(s) changes.append(d) copies[d] = s return changes, copies def _obtainrevision(self, rev): self.ui.debug('obtaining revision %s...\n' % rev) output = self._execute('get', rev, self.tmppath) self.checkexit(output) self.ui.debug('analyzing revision %s...\n' % rev) files = self._readcontents(self.tmppath) self.changes[rev].add_files += files def _stripbasepath(self, path): if path.startswith('./'): return path[2:] return path def _parsecatlog(self, data, rev): try: catlog = self.catlogparser.parsestr(data) # Commit date self.changes[rev].date = util.datestr( util.strdate(catlog['Standard-date'], '%Y-%m-%d %H:%M:%S')) # Commit author self.changes[rev].author = self.recode(catlog['Creator']) # Commit description self.changes[rev].summary = '\n\n'.join((catlog['Summary'], catlog.get_payload())) self.changes[rev].summary = self.recode(self.changes[rev].summary) # Commit revision origin when dealing with a branch or tag if 'Continuation-of' in catlog: self.changes[rev].continuationof = self.recode( catlog['Continuation-of']) except Exception: raise error.Abort(_('could not parse cat-log of %s') % rev) def _parsechangeset(self, data, rev): for l in data: l = l.strip() # Added file (ignore added directory) if l.startswith('A') and not l.startswith('A/'): file = self._stripbasepath(l[1:].strip()) if not self._exclude(file): self.changes[rev].add_files.append(file) # Deleted file (ignore deleted directory) elif l.startswith('D') and not l.startswith('D/'): file = self._stripbasepath(l[1:].strip()) if not self._exclude(file): self.changes[rev].del_files.append(file) # Modified binary file elif l.startswith('Mb'): file = self._stripbasepath(l[2:].strip()) if not self._exclude(file): self.changes[rev].mod_files.append(file) # Modified link elif l.startswith('M->'): file = self._stripbasepath(l[3:].strip()) if not self._exclude(file): self.changes[rev].mod_files.append(file) # Modified file elif l.startswith('M'): file = self._stripbasepath(l[1:].strip()) if not self._exclude(file): self.changes[rev].mod_files.append(file) # Renamed file (or link) elif l.startswith('=>'): files = l[2:].strip().split(' ') if len(files) == 1: files = l[2:].strip().split('\t') src = self._stripbasepath(files[0]) dst = self._stripbasepath(files[1]) if not self._exclude(src) and not self._exclude(dst): self.changes[rev].ren_files[src] = dst # Conversion from file to link or from link to file (modified) elif l.startswith('ch'): file = self._stripbasepath(l[2:].strip()) if not self._exclude(file): self.changes[rev].mod_files.append(file) # Renamed directory elif l.startswith('/>'): dirs = l[2:].strip().split(' ') if len(dirs) == 1: dirs = l[2:].strip().split('\t') src = self._stripbasepath(dirs[0]) dst = self._stripbasepath(dirs[1]) if not self._exclude(src) and not self._exclude(dst): self.changes[rev].ren_dirs[src] = dst