bdiff: give slight preference to appending lines
[This change could be folded into the previous changeset to minimize the repo
churn ...]
The general preference to matches in the middle of bdiff ranges helps getting
balanced recursion and efficient computation. But, as previous changes have
shown, it might also give diffs that seems "obviously wrong".
To mitigate that: If the best match on the A side starts at the beginning of
the bdiff range, don't aim for the middle-most B side match but for the
earliest.
This will make the matches balanced (by both sides being "early") even though
the bisection will be less balanced. Still, this case only apply if the *best*
and middle-most match was fully unbalanced on the A side. Each recursion will
thus even in this worst case reduce the problem significantly and we are not
re-introducing the problem that was fixed in f1ca249696ed.
The bundle size for 4.0 (hg bundle --base null -r 4.0 x.hg) happens to go from
22806817 to 22807275 bytes - a 0.002% increase.
This make the recent test-bdiff.py changes give a more pretty output ... but
they no longer show that the recursion is around middle matches (because it in
these cases isn't).
# 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 (
cmdutil,
encoding,
error,
match as matchmod,
scmutil,
util,
)
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, str):
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']
def buildmetadata(ctx):
'''build content of .hg_archival.txt'''
repo = ctx.repo()
hex = ctx.hex()
if ctx.rev() is None:
hex = ctx.p1().hex()
if ctx.dirty():
hex += '+'
base = 'repo: %s\nnode: %s\nbranch: %s\n' % (
_rootctx(repo).hex(), hex, encoding.fromlocal(ctx.branch()))
tags = ''.join('tag: %s\n' % t for t in ctx.tags()
if repo.tagtype(t) == 'global')
if not tags:
repo.ui.pushbuffer()
opts = {'template': '{latesttag}\n{latesttagdistance}\n'
'{changessincelatesttag}',
'style': '', 'patch': None, 'git': None}
cmdutil.show_changeset(repo.ui, repo, opts).show(ctx)
ltags, dist, changessince = repo.ui.popbuffer().split('\n')
ltags = ltags.split(':')
tags = ''.join('latesttag: %s\n' % t for t in ltags)
tags += 'latesttagdistance: %s\n' % dist
tags += 'changessincelatesttag: %s\n' % changessince
return base + tags
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 'timestamp' in kw:
timestamp = kw.pop('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(chr(flags))
gzip.write32u(self.fileobj, long(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(name, mode, fileobj=None):
if kind == 'gz':
mode = mode[0]
if not fileobj:
fileobj = open(name, mode + 'b')
gzfileobj = self.GzipFileWithTime(name, mode + 'b',
zlib.Z_BEST_COMPRESSION,
fileobj, timestamp=mtime)
self.fileobj = gzfileobj
return tarfile.TarFile.taropen(name, mode, gzfileobj)
else:
return tarfile.open(name, mode + kind, fileobj)
if isinstance(dest, str):
self.z = taropen(dest, mode='w:')
else:
# Python 2.5-2.5.1 have a regression that requires a name arg
self.z = taropen(name='', mode='w|', fileobj=dest)
def addfile(self, name, mode, islink, data):
i = tarfile.TarInfo(name)
i.mtime = self.mtime
i.size = len(data)
if islink:
i.type = tarfile.SYMTYPE
i.mode = 0o777
i.linkname = 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, str):
try:
dest.tell()
except (AttributeError, IOError):
dest = tellable(dest)
self.z = zipfile.ZipFile(dest, '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(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 = scmutil.opener(self.basedir)
def addfile(self, name, mode, islink, data):
if islink:
self.opener.symlink(data, name)
return
f = self.opener(name, "w", atomictemp=True)
f.write(data)
f.close()
destfile = os.path.join(self.basedir, name)
os.chmod(destfile, mode)
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.'''
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", True):
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()
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)
if total == 0:
raise error.Abort(_('no files match the archive pattern'))
archiver.done()
return total