checknlink: return False if .hgtmp file preexists (issue2517)
If os_link fails on Windows, errno is always errno.EINVAL,
so we can't really say if the testlink could not be created
because (a) the FS doesn't support hardlinks or (b) there
is a leaked .hgtmp file lying around from a previous crashed
run.
So let's err on the safe side, keep the code simple and assume
we can't detect hardlinks in both cases.
# changegroup.py - Mercurial changegroup manipulation functions
#
# Copyright 2006 Matt Mackall <mpm@selenic.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 _
import util
import struct, os, bz2, zlib, tempfile
def getchunk(source):
"""return the next chunk from changegroup 'source' as a string"""
d = source.read(4)
if not d:
return ""
l = struct.unpack(">l", d)[0]
if l <= 4:
return ""
d = source.read(l - 4)
if len(d) < l - 4:
raise util.Abort(_("premature EOF reading chunk"
" (got %d bytes, expected %d)")
% (len(d), l - 4))
return d
def chunkheader(length):
"""return a changegroup chunk header (string)"""
return struct.pack(">l", length + 4)
def closechunk():
"""return a changegroup chunk header (string) for a zero-length chunk"""
return struct.pack(">l", 0)
class nocompress(object):
def compress(self, x):
return x
def flush(self):
return ""
bundletypes = {
"": ("", nocompress),
"HG10UN": ("HG10UN", nocompress),
"HG10BZ": ("HG10", lambda: bz2.BZ2Compressor()),
"HG10GZ": ("HG10GZ", lambda: zlib.compressobj()),
}
def collector(cl, mmfs, files):
# Gather information about changeset nodes going out in a bundle.
# We want to gather manifests needed and filelogs affected.
def collect(node):
c = cl.read(node)
files.update(c[3])
mmfs.setdefault(c[0], node)
return collect
# hgweb uses this list to communicate its preferred type
bundlepriority = ['HG10GZ', 'HG10BZ', 'HG10UN']
def writebundle(cg, filename, bundletype):
"""Write a bundle file and return its filename.
Existing files will not be overwritten.
If no filename is specified, a temporary file is created.
bz2 compression can be turned off.
The bundle file will be deleted in case of errors.
"""
fh = None
cleanup = None
try:
if filename:
fh = open(filename, "wb")
else:
fd, filename = tempfile.mkstemp(prefix="hg-bundle-", suffix=".hg")
fh = os.fdopen(fd, "wb")
cleanup = filename
header, compressor = bundletypes[bundletype]
fh.write(header)
z = compressor()
# parse the changegroup data, otherwise we will block
# in case of sshrepo because we don't know the end of the stream
# an empty chunkgroup is the end of the changegroup
# a changegroup has at least 2 chunkgroups (changelog and manifest).
# after that, an empty chunkgroup is the end of the changegroup
empty = False
count = 0
while not empty or count <= 2:
empty = True
count += 1
while 1:
chunk = getchunk(cg)
if not chunk:
break
empty = False
fh.write(z.compress(chunkheader(len(chunk))))
pos = 0
while pos < len(chunk):
next = pos + 2**20
fh.write(z.compress(chunk[pos:next]))
pos = next
fh.write(z.compress(closechunk()))
fh.write(z.flush())
cleanup = None
return filename
finally:
if fh is not None:
fh.close()
if cleanup is not None:
os.unlink(cleanup)
def decompressor(fh, alg):
if alg == 'UN':
return fh
elif alg == 'GZ':
def generator(f):
zd = zlib.decompressobj()
for chunk in f:
yield zd.decompress(chunk)
elif alg == 'BZ':
def generator(f):
zd = bz2.BZ2Decompressor()
zd.decompress("BZ")
for chunk in util.filechunkiter(f, 4096):
yield zd.decompress(chunk)
else:
raise util.Abort("unknown bundle compression '%s'" % alg)
return util.chunkbuffer(generator(fh))
class unbundle10(object):
def __init__(self, fh, alg):
self._stream = decompressor(fh, alg)
self._type = alg
self.callback = None
def compressed(self):
return self._type != 'UN'
def read(self, l):
return self._stream.read(l)
def seek(self, pos):
return self._stream.seek(pos)
def tell(self):
return self._stream.tell()
def close(self):
return self._stream.close()
def chunklength(self):
d = self.read(4)
if not d:
return 0
l = max(0, struct.unpack(">l", d)[0] - 4)
if l and self.callback:
self.callback()
return l
def chunk(self):
"""return the next chunk from changegroup 'source' as a string"""
l = self.chunklength()
d = self.read(l)
if len(d) < l:
raise util.Abort(_("premature EOF reading chunk"
" (got %d bytes, expected %d)")
% (len(d), l))
return d
def parsechunk(self):
l = self.chunklength()
if not l:
return {}
h = self.read(80)
node, p1, p2, cs = struct.unpack("20s20s20s20s", h)
data = self.read(l - 80)
return dict(node=node, p1=p1, p2=p2, cs=cs, data=data)
class headerlessfixup(object):
def __init__(self, fh, h):
self._h = h
self._fh = fh
def read(self, n):
if self._h:
d, self._h = self._h[:n], self._h[n:]
if len(d) < n:
d += self._fh.read(n - len(d))
return d
return self._fh.read(n)
def readbundle(fh, fname):
header = fh.read(6)
if not fname:
fname = "stream"
if not header.startswith('HG') and header.startswith('\0'):
fh = headerlessfixup(fh, header)
header = "HG10UN"
magic, version, alg = header[0:2], header[2:4], header[4:6]
if magic != 'HG':
raise util.Abort(_('%s: not a Mercurial bundle') % fname)
if version != '10':
raise util.Abort(_('%s: unknown bundle version %s') % (fname, version))
return unbundle10(fh, alg)