Mercurial > hg
view mercurial/changegroup.py @ 7104:9514cbb6e4f6
bdiff: normalize the diff (issue1295)
When the common part of a diff can be moved forward, move it forward.
Otherwise we don't get deterministic results (it would depends on the way we
split for the recursion).
That way we get identical hunks when doing the same change, it helps to solve
issue1295 (inconsistent diffs on different side during a merge).
author | Benoit Boissinot <benoit.boissinot@ens-lyon.org> |
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date | Tue, 14 Oct 2008 20:13:53 +0200 |
parents | ef1c5a3b653d |
children | 46293a0c7e9f |
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""" 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, incorporated herein by reference. """ from i18n import _ import struct, os, bz2, zlib, util, tempfile def getchunk(source): """get a chunk from a changegroup""" 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 chunkiter(source): """iterate through the chunks in source""" while 1: c = getchunk(source) if not c: break yield c def chunkheader(length): """build a changegroup chunk header""" return struct.pack(">l", length + 4) def closechunk(): 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()), } # hgweb uses this list to communicate it's 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 chunkiter is the end of the changegroup # a changegroup has at least 2 chunkiters (changelog and manifest). # after that, an empty chunkiter is the end of the changegroup empty = False count = 0 while not empty or count <= 2: empty = True count += 1 for chunk in chunkiter(cg): 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 unbundle(header, fh): if header == 'HG10UN': return fh elif not header.startswith('HG'): # old client with uncompressed bundle def generator(f): yield header for chunk in f: yield chunk elif header == 'HG10GZ': def generator(f): zd = zlib.decompressobj() for chunk in f: yield zd.decompress(chunk) elif header == 'HG10BZ': def generator(f): zd = bz2.BZ2Decompressor() zd.decompress("BZ") for chunk in util.filechunkiter(f, 4096): yield zd.decompress(chunk) return util.chunkbuffer(generator(fh)) def readbundle(fh, fname): header = fh.read(6) if not header.startswith('HG'): raise util.Abort(_('%s: not a Mercurial bundle file') % fname) if not header.startswith('HG10'): raise util.Abort(_('%s: unknown bundle version') % fname) elif header not in bundletypes: raise util.Abort(_('%s: unknown bundle compression type') % fname) return unbundle(header, fh)