ancestor: a new algorithm that is faster for nodes near tip
Instead of walking all the way to the root of the DAG, we generate
a set of candidate GCA revs, then figure out which ones will win
the race to the root (usually without needing to traverse all the
way to the root).
In the common case of nodes that are close to each other in both
revision number and topology, this is usually a big win: it makes
"hg --time debugancestors" up to 9 times faster than the more general
ancestor function when measured on heads of the linux-2.6 hg repo.
Victory is not assured, however. The older function can still win
by a large margin if one node is much closer to the root than the
other, or by a much smaller amount if one is an ancestor of the
other.
For now, we've also got a small paranoid harness function that calls
both ancestor functions on every input and ensures that they give
equivalent answers.
Even without the checker function, the old ancestor function needs
to stay alive for the time being, as its generality is used by
context.filectx.merge.
# 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 i18n import _
from node import hex
import match as matchmod
import cmdutil
import scmutil, util, encoding
import cStringIO, os, tarfile, time, zipfile
import zlib, gzip
import struct
import error
# 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 += '/'
if prefix.startswith('../') or os.path.isabs(lpfx) or '/../' in prefix:
raise util.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 util.any(dest.endswith(ext) for ext in extensions):
return kind
return None
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
# Python 2.6 introduced self.name and deprecated self.filename
try:
fname = self.name
except AttributeError:
fname = self.filename
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 = 0777
i.linkname = data
data = None
i.size = 0
else:
i.mode = mode
data = cStringIO.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 = 0777
ftype = _UNX_IFLNK
i.external_attr = (mode | ftype) << 16L
# 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=None, 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 util.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 util.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):
def metadata():
base = 'repo: %s\nnode: %s\nbranch: %s\n' % (
repo[0].hex(), hex(node), 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}',
'style': '', 'patch': None, 'git': None}
cmdutil.show_changeset(repo.ui, repo, opts).show(ctx)
ltags, dist = repo.ui.popbuffer().split('\n')
tags = ''.join('latesttag: %s\n' % t for t in ltags.split(':'))
tags += 'latesttagdistance: %s\n' % dist
return base + tags
name = '.hg_archival.txt'
if not matchfn or matchfn(name):
write(name, 0644, False, metadata)
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 0755 or 0644, '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.sub(subpath)
submatch = matchmod.narrowmatcher(subpath, matchfn)
total += sub.archive(repo.ui, archiver, prefix, submatch)
if total == 0:
raise error.Abort(_('no files match the archive pattern'))
archiver.done()
return total