Mercurial > hg > mercurial-crew-with-dirclash
view mercurial/changegroup.py @ 5192:33015dac5df5
convert: fix mercurial_sink.putcommit
Changeset 4ebc8693ce72 added some code to putcommit to avoid creating a
revision that touches no files, but this can break regular conversions
from some repositories:
- conceptually, since we're converting a repo, we should try to make
the new hg repo as similar as possible to the original repo - we
should create a new changeset, even if the original revision didn't
touch any files (maybe the commit message had some important bit);
- even if a "regular" revision that doesn't touch any file may seem
weird (and maybe even broken), it's completely legitimate for a merge
revision to not touch any file, and, if we just skip it, the
converted repo will end up with wrong history and possibly an extra
head.
As an example, say the crew and main hg repos are sync'ed. Somebody
sends an important patch to the mailing list. Matt quickly applies
and pushes it. But at the same time somebody also applies it to crew
and pushes it. Suppose the commit message ended up being a bit
different (say, there was a typo and somebody didn't fix it) or that
the date ended up being different (because of different patch-applying
scripts): the changeset hashes will be different, but the manifests
will be the same.
Since both changesets were pushed to public repos, it's hard to recall
them. If both are merged, the manifest from the resulting merge
revision will have the exact same contents as its parents - i.e. the
merge revision really doesn't touch any file at all.
To keep the file filtering stuff "working", the generic code was changed
to skip empty revisions if we're filtering the repo, fixing a bug in the
process (we want parents[0] instead of tip).
author | Alexis S. L. Carvalho <alexis@cecm.usp.br> |
---|---|
date | Fri, 17 Aug 2007 20:18:05 -0300 |
parents | e0793314360e |
children | 61462e7d62ed |
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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 genchunk(data): """build a changegroup chunk""" header = struct.pack(">l", len(data)+ 4) return "%s%s" % (header, data) 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()), } 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 empty = False while not empty: empty = True for chunk in chunkiter(cg): empty = False fh.write(z.compress(genchunk(chunk))) 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 readbundle(fh, fname): header = fh.read(6) if not header.startswith("HG"): raise util.Abort(_("%s: not a Mercurial bundle file") % fname) elif not header.startswith("HG10"): raise util.Abort(_("%s: unknown bundle version") % fname) if 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)) elif header == "HG10UN": return fh raise util.Abort(_("%s: unknown bundle compression type") % fname)