diff options
Diffstat (limited to 'websdk/mercurial/changegroup.py')
| -rw-r--r--[l---------] | websdk/mercurial/changegroup.py | 257 |
1 files changed, 256 insertions, 1 deletions
diff --git a/websdk/mercurial/changegroup.py b/websdk/mercurial/changegroup.py index 6ea0821..7ee7b3f 120000..100644 --- a/websdk/mercurial/changegroup.py +++ b/websdk/mercurial/changegroup.py @@ -1 +1,256 @@ -/usr/share/pyshared/mercurial/changegroup.py
\ No newline at end of file +# 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 _ +from node import nullrev +import mdiff, util +import struct, os, bz2, zlib, tempfile + +_BUNDLE10_DELTA_HEADER = "20s20s20s20s" + +def readexactly(stream, n): + '''read n bytes from stream.read and abort if less was available''' + s = stream.read(n) + if len(s) < n: + raise util.Abort(_("stream ended unexpectedly" + " (got %d bytes, expected %d)") + % (len(s), n)) + return s + +def getchunk(stream): + """return the next chunk from stream as a string""" + d = readexactly(stream, 4) + l = struct.unpack(">l", d)[0] + if l <= 4: + if l: + raise util.Abort(_("invalid chunk length %d") % l) + return "" + return readexactly(stream, l - 4) + +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), # only when using unbundle on ssh and old http servers + # since the unification ssh accepts a header but there + # is no capability signaling it. + "HG10UN": ("HG10UN", nocompress), + "HG10BZ": ("HG10", lambda: bz2.BZ2Compressor()), + "HG10GZ": ("HG10GZ", lambda: zlib.compressobj()), +} + +# 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 True: + 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): + deltaheader = _BUNDLE10_DELTA_HEADER + deltaheadersize = struct.calcsize(deltaheader) + 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 = readexactly(self._stream, 4) + l = struct.unpack(">l", d)[0] + if l <= 4: + if l: + raise util.Abort(_("invalid chunk length %d") % l) + return 0 + if self.callback: + self.callback() + return l - 4 + + def changelogheader(self): + """v10 does not have a changelog header chunk""" + return {} + + def manifestheader(self): + """v10 does not have a manifest header chunk""" + return {} + + def filelogheader(self): + """return the header of the filelogs chunk, v10 only has the filename""" + l = self.chunklength() + if not l: + return {} + fname = readexactly(self._stream, l) + return dict(filename=fname) + + def _deltaheader(self, headertuple, prevnode): + node, p1, p2, cs = headertuple + if prevnode is None: + deltabase = p1 + else: + deltabase = prevnode + return node, p1, p2, deltabase, cs + + def deltachunk(self, prevnode): + l = self.chunklength() + if not l: + return {} + headerdata = readexactly(self._stream, self.deltaheadersize) + header = struct.unpack(self.deltaheader, headerdata) + delta = readexactly(self._stream, l - self.deltaheadersize) + node, p1, p2, deltabase, cs = self._deltaheader(header, prevnode) + return dict(node=node, p1=p1, p2=p2, cs=cs, + deltabase=deltabase, delta=delta) + +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 += readexactly(self._fh, n - len(d)) + return d + return readexactly(self._fh, n) + +def readbundle(fh, fname): + header = readexactly(fh, 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) + +class bundle10(object): + deltaheader = _BUNDLE10_DELTA_HEADER + def __init__(self, lookup): + self._lookup = lookup + def close(self): + return closechunk() + def fileheader(self, fname): + return chunkheader(len(fname)) + fname + def revchunk(self, revlog, rev, prev): + node = revlog.node(rev) + p1, p2 = revlog.parentrevs(rev) + base = prev + + prefix = '' + if base == nullrev: + delta = revlog.revision(node) + prefix = mdiff.trivialdiffheader(len(delta)) + else: + delta = revlog.revdiff(base, rev) + linknode = self._lookup(revlog, node) + p1n, p2n = revlog.parents(node) + basenode = revlog.node(base) + meta = self.builddeltaheader(node, p1n, p2n, basenode, linknode) + meta += prefix + l = len(meta) + len(delta) + yield chunkheader(l) + yield meta + yield delta + def builddeltaheader(self, node, p1n, p2n, basenode, linknode): + # do nothing with basenode, it is implicitly the previous one in HG10 + return struct.pack(self.deltaheader, node, p1n, p2n, linknode) |