transaction: avoid file stat ambiguity only for files in blacklist
Advancing mtime by os.utime() fails for EPERM, if the target file is
owned by another.
bff5ccbe5ead and related changes made some code
paths give advancing mtime up in such case, to fix
issue5418.
This causes file stat ambiguity (again), if it is owned by another.
https://www.mercurial-scm.org/wiki/ExactCacheValidationPlan
To avoid file stat ambiguity in such case, especially for
.hg/dirstate,
ed66ec39933f made vfs.rename() copy the target file, and
advance mtime of renamed one again, if EPERM (see
issue5584 for detail).
But straightforward "copy if EPERM" isn't reasonable for truncation of
append-only files at rollbacking, because rollbacking might cost much
for truncation of many filelogs, even though filelogs aren't
filecache-ed.
Therefore, this patch introduces blacklist "checkambigfiles", and
avoids file stat ambiguity only for files specified in this blacklist.
This patch consists of two parts below, which should be applied at
once in order to avoid regression.
- specify 'checkambig=True' at vfs.open(mode='a') in _playback()
according to checkambigfiles
- invoke _playback() with checkambigfiles
- add transaction.__init__() checkambigfiles argument, for _abort()
- make localrepo instantiate transaction with _cachedfiles
- add rollback() checkambigfiles argument, for "hg rollback/recover"
- make localrepo invoke rollback() with _cachedfiles
After this patch, straightforward "copy if EPERM" will be reasonable
at closing the file opened with checkambig=True, because this policy
is applied only on files, which are listed in blacklist
"checkambigfiles".
# 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,
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, 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(mode, name='', 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('w:', name=dest)
else:
self.z = taropen('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 = vfsmod.vfs(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, decode)
if total == 0:
raise error.Abort(_('no files match the archive pattern'))
archiver.done()
return total