##// END OF EJS Templates
xdiff: add a preprocessing step that trims files...
xdiff: add a preprocessing step that trims files xdiff has a `xdl_trim_ends` step that removes common lines, unmatchable lines. That is in theory good, but happens too late - after splitting, hashing, and adjusting the hash values so they are unique. Those splitting, hashing and adjusting hash values steps could have noticeable overhead. Diffing two large files with minor (one-line-ish) changes are not uncommon. In that case, the raw performance of those preparation steps seriously matter. Even allocating an O(N) array and storing line offsets to it is expensive. Therefore my previous attempts [1] [2] cannot be good enough since they do not remove the O(N) array assignment. This patch adds a preprocessing step - `xdl_trim_files` that runs before other preprocessing steps. It counts common prefix and suffix and lines in them (needed for displaying line number), without doing anything else. Testing with a crafted large (169MB) file, with minor change: ``` open('a','w').write(''.join('%s\n' % (i % 100000) for i in xrange(30000000) if i != 6000000)) open('b','w').write(''.join('%s\n' % (i % 100000) for i in xrange(30000000) if i != 6003000)) ``` Running xdiff by a simple binary [3], this patch improves the xdiff perf by more than 10x for the above case: ``` # xdiff before this patch 2.41s user 1.13s system 98% cpu 3.592 total # xdiff after this patch 0.14s user 0.16s system 98% cpu 0.309 total # gnu diffutils 0.12s user 0.15s system 98% cpu 0.272 total # (best of 20 runs) ``` It's still slightly slower than GNU diffutils. But it's pretty close now. Testing with real repo data: For the whole repo, this patch makes xdiff 25% faster: ``` # hg perfbdiff --count 100 --alldata -c d334afc585e2 --blocks [--xdiff] # xdiff, after ! wall 0.058861 comb 0.050000 user 0.050000 sys 0.000000 (best of 100) # xdiff, before ! wall 0.077816 comb 0.080000 user 0.080000 sys 0.000000 (best of 91) # bdiff ! wall 0.117473 comb 0.120000 user 0.120000 sys 0.000000 (best of 67) ``` For files that are long (ex. commands.py), the speedup is more than 3x, very significant: ``` # hg perfbdiff --count 3000 --blocks commands.py.i 1 [--xdiff] # xdiff, after ! wall 0.690583 comb 0.690000 user 0.690000 sys 0.000000 (best of 12) # xdiff, before ! wall 2.240361 comb 2.210000 user 2.210000 sys 0.000000 (best of 4) # bdiff ! wall 2.469852 comb 2.440000 user 2.440000 sys 0.000000 (best of 4) ``` [1]: https://phab.mercurial-scm.org/D2631 [2]: https://phab.mercurial-scm.org/D2634 [3]: ``` // Code to run xdiff from command line. No proper error handling. #include <stdlib.h> #include <unistd.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include "mercurial/thirdparty/xdiff/xdiff.h" #define ensure(x) if (!(x)) exit(255); mmfile_t readfile(const char *path) { struct stat st; int fd = open(path, O_RDONLY); fstat(fd, &st); mmfile_t file = { malloc(st.st_size), st.st_size }; ensure(read(fd, file.ptr, st.st_size) == st.st_size); close(fd); return file; } int main(int argc, char const *argv[]) { mmfile_t a = readfile(argv[1]), b = readfile(argv[2]); xpparam_t xpp = {0}; xdemitconf_t xecfg = {0}; xdemitcb_t ecb = {0}; xdl_diff(&a, &b, &xpp, &xecfg, &ecb); return 0; } ``` Differential Revision: https://phab.mercurial-scm.org/D2686

File last commit:

r36785:a148c67d default
r36838:f33a87cf default
Show More
archival.py
365 lines | 11.3 KiB | text/x-python | PythonLexer
# archival.py - revision archival for mercurial
#
# Copyright 2006 Vadim Gelfer <vadim.gelfer@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.
from __future__ import absolute_import
import gzip
import os
import struct
import tarfile
import time
import zipfile
import zlib
from .i18n import _
from . import (
error,
formatter,
match as matchmod,
pycompat,
scmutil,
util,
vfs as vfsmod,
)
stringio = util.stringio
# from unzip source code:
_UNX_IFREG = 0x8000
_UNX_IFLNK = 0xa000
def tidyprefix(dest, kind, prefix):
'''choose prefix to use for names in archive. make sure prefix is
safe for consumers.'''
if prefix:
prefix = util.normpath(prefix)
else:
if not isinstance(dest, bytes):
raise ValueError('dest must be string if no prefix')
prefix = os.path.basename(dest)
lower = prefix.lower()
for sfx in exts.get(kind, []):
if lower.endswith(sfx):
prefix = prefix[:-len(sfx)]
break
lpfx = os.path.normpath(util.localpath(prefix))
prefix = util.pconvert(lpfx)
if not prefix.endswith('/'):
prefix += '/'
# Drop the leading '.' path component if present, so Windows can read the
# zip files (issue4634)
if prefix.startswith('./'):
prefix = prefix[2:]
if prefix.startswith('../') or os.path.isabs(lpfx) or '/../' in prefix:
raise error.Abort(_('archive prefix contains illegal components'))
return prefix
exts = {
'tar': ['.tar'],
'tbz2': ['.tbz2', '.tar.bz2'],
'tgz': ['.tgz', '.tar.gz'],
'zip': ['.zip'],
}
def guesskind(dest):
for kind, extensions in exts.iteritems():
if any(dest.endswith(ext) for ext in extensions):
return kind
return None
def _rootctx(repo):
# repo[0] may be hidden
for rev in repo:
return repo[rev]
return repo['null']
# {tags} on ctx includes local tags and 'tip', with no current way to limit
# that to global tags. Therefore, use {latesttag} as a substitute when
# the distance is 0, since that will be the list of global tags on ctx.
_defaultmetatemplate = br'''
repo: {root}
node: {ifcontains(rev, revset("wdir()"), "{p1node}{dirty}", "{node}")}
branch: {branch|utf8}
{ifeq(latesttagdistance, 0, join(latesttag % "tag: {tag}", "\n"),
separate("\n",
join(latesttag % "latesttag: {tag}", "\n"),
"latesttagdistance: {latesttagdistance}",
"changessincelatesttag: {changessincelatesttag}"))}
'''[1:] # drop leading '\n'
def buildmetadata(ctx):
'''build content of .hg_archival.txt'''
repo = ctx.repo()
opts = {
'template': repo.ui.config('experimental', 'archivemetatemplate',
_defaultmetatemplate)
}
out = util.stringio()
fm = formatter.formatter(repo.ui, out, 'archive', opts)
fm.startitem()
fm.context(ctx=ctx)
fm.data(root=_rootctx(repo).hex())
if ctx.rev() is None:
dirty = ''
if ctx.dirty(missing=True):
dirty = '+'
fm.data(dirty=dirty)
fm.end()
return out.getvalue()
class tarit(object):
'''write archive to tar file or stream. can write uncompressed,
or compress with gzip or bzip2.'''
class GzipFileWithTime(gzip.GzipFile):
def __init__(self, *args, **kw):
timestamp = None
if r'timestamp' in kw:
timestamp = kw.pop(r'timestamp')
if timestamp is None:
self.timestamp = time.time()
else:
self.timestamp = timestamp
gzip.GzipFile.__init__(self, *args, **kw)
def _write_gzip_header(self):
self.fileobj.write('\037\213') # magic header
self.fileobj.write('\010') # compression method
fname = self.name
if fname and fname.endswith('.gz'):
fname = fname[:-3]
flags = 0
if fname:
flags = gzip.FNAME
self.fileobj.write(pycompat.bytechr(flags))
gzip.write32u(self.fileobj, int(self.timestamp))
self.fileobj.write('\002')
self.fileobj.write('\377')
if fname:
self.fileobj.write(fname + '\000')
def __init__(self, dest, mtime, kind=''):
self.mtime = mtime
self.fileobj = None
def taropen(mode, name='', fileobj=None):
if kind == 'gz':
mode = mode[0:1]
if not fileobj:
fileobj = open(name, mode + 'b')
gzfileobj = self.GzipFileWithTime(name,
pycompat.sysstr(mode + 'b'),
zlib.Z_BEST_COMPRESSION,
fileobj, timestamp=mtime)
self.fileobj = gzfileobj
return tarfile.TarFile.taropen(
name, pycompat.sysstr(mode), gzfileobj)
else:
return tarfile.open(
name, pycompat.sysstr(mode + kind), fileobj)
if isinstance(dest, bytes):
self.z = taropen('w:', name=dest)
else:
self.z = taropen('w|', fileobj=dest)
def addfile(self, name, mode, islink, data):
name = pycompat.fsdecode(name)
i = tarfile.TarInfo(name)
i.mtime = self.mtime
i.size = len(data)
if islink:
i.type = tarfile.SYMTYPE
i.mode = 0o777
i.linkname = pycompat.fsdecode(data)
data = None
i.size = 0
else:
i.mode = mode
data = stringio(data)
self.z.addfile(i, data)
def done(self):
self.z.close()
if self.fileobj:
self.fileobj.close()
class tellable(object):
'''provide tell method for zipfile.ZipFile when writing to http
response file object.'''
def __init__(self, fp):
self.fp = fp
self.offset = 0
def __getattr__(self, key):
return getattr(self.fp, key)
def write(self, s):
self.fp.write(s)
self.offset += len(s)
def tell(self):
return self.offset
class zipit(object):
'''write archive to zip file or stream. can write uncompressed,
or compressed with deflate.'''
def __init__(self, dest, mtime, compress=True):
if not isinstance(dest, bytes):
try:
dest.tell()
except (AttributeError, IOError):
dest = tellable(dest)
self.z = zipfile.ZipFile(pycompat.fsdecode(dest), r'w',
compress and zipfile.ZIP_DEFLATED or
zipfile.ZIP_STORED)
# Python's zipfile module emits deprecation warnings if we try
# to store files with a date before 1980.
epoch = 315532800 # calendar.timegm((1980, 1, 1, 0, 0, 0, 1, 1, 0))
if mtime < epoch:
mtime = epoch
self.mtime = mtime
self.date_time = time.gmtime(mtime)[:6]
def addfile(self, name, mode, islink, data):
i = zipfile.ZipInfo(pycompat.fsdecode(name), self.date_time)
i.compress_type = self.z.compression
# unzip will not honor unix file modes unless file creator is
# set to unix (id 3).
i.create_system = 3
ftype = _UNX_IFREG
if islink:
mode = 0o777
ftype = _UNX_IFLNK
i.external_attr = (mode | ftype) << 16
# add "extended-timestamp" extra block, because zip archives
# without this will be extracted with unexpected timestamp,
# if TZ is not configured as GMT
i.extra += struct.pack('<hhBl',
0x5455, # block type: "extended-timestamp"
1 + 4, # size of this block
1, # "modification time is present"
int(self.mtime)) # last modification (UTC)
self.z.writestr(i, data)
def done(self):
self.z.close()
class fileit(object):
'''write archive as files in directory.'''
def __init__(self, name, mtime):
self.basedir = name
self.opener = vfsmod.vfs(self.basedir)
self.mtime = mtime
def addfile(self, name, mode, islink, data):
if islink:
self.opener.symlink(data, name)
return
f = self.opener(name, "w", atomictemp=False)
f.write(data)
f.close()
destfile = os.path.join(self.basedir, name)
os.chmod(destfile, mode)
if self.mtime is not None:
os.utime(destfile, (self.mtime, self.mtime))
def done(self):
pass
archivers = {
'files': fileit,
'tar': tarit,
'tbz2': lambda name, mtime: tarit(name, mtime, 'bz2'),
'tgz': lambda name, mtime: tarit(name, mtime, 'gz'),
'uzip': lambda name, mtime: zipit(name, mtime, False),
'zip': zipit,
}
def archive(repo, dest, node, kind, decode=True, matchfn=None,
prefix='', mtime=None, subrepos=False):
'''create archive of repo as it was at node.
dest can be name of directory, name of archive file, or file
object to write archive to.
kind is type of archive to create.
decode tells whether to put files through decode filters from
hgrc.
matchfn is function to filter names of files to write to archive.
prefix is name of path to put before every archive member.
mtime is the modified time, in seconds, or None to use the changeset time.
subrepos tells whether to include subrepos.
'''
if kind == 'files':
if prefix:
raise error.Abort(_('cannot give prefix when archiving to files'))
else:
prefix = tidyprefix(dest, kind, prefix)
def write(name, mode, islink, getdata):
data = getdata()
if decode:
data = repo.wwritedata(name, data)
archiver.addfile(prefix + name, mode, islink, data)
if kind not in archivers:
raise error.Abort(_("unknown archive type '%s'") % kind)
ctx = repo[node]
archiver = archivers[kind](dest, mtime or ctx.date()[0])
if repo.ui.configbool("ui", "archivemeta"):
name = '.hg_archival.txt'
if not matchfn or matchfn(name):
write(name, 0o644, False, lambda: buildmetadata(ctx))
if matchfn:
files = [f for f in ctx.manifest().keys() if matchfn(f)]
else:
files = ctx.manifest().keys()
total = len(files)
if total:
files.sort()
scmutil.fileprefetchhooks(repo, ctx, files)
repo.ui.progress(_('archiving'), 0, unit=_('files'), total=total)
for i, f in enumerate(files):
ff = ctx.flags(f)
write(f, 'x' in ff and 0o755 or 0o644, 'l' in ff, ctx[f].data)
repo.ui.progress(_('archiving'), i + 1, item=f,
unit=_('files'), total=total)
repo.ui.progress(_('archiving'), None)
if subrepos:
for subpath in sorted(ctx.substate):
sub = ctx.workingsub(subpath)
submatch = matchmod.subdirmatcher(subpath, matchfn)
total += sub.archive(archiver, prefix, submatch, decode)
if total == 0:
raise error.Abort(_('no files match the archive pattern'))
archiver.done()
return total