make incoming work via ssh (issue139); move chunk code into separate module.

Incoming ssh needs to detect the end of the changegroup, otherwise it would
block trying to read from the ssh pipe. This is done by parsing the
changegroup chunks.

bundlerepo.getchunk() already is identical to
localrepo.addchangegroup.getchunk(), which is followed by getgroup which
looks much like what you can re-use in bundlerepository.__init__() and in
write_bundle(). bundlerevlog.__init__.genchunk() looks very similar, too,
as do some while loops in localrepo.py.

Applied patch from Benoit Boissinot to move duplicate/related code
to mercurial/changegroup.py and use this to fix incoming ssh.

mercurial/changegroup.py

@@ -0,0 +1,43 b''
+"""
+changegroup.py - Mercurial changegroup manipulation functions
+
+ Copyright 2006 Matt Mackall <[e-mail]>
+
+This software may be used and distributed according to the terms
+of the GNU General Public License, incorporated herein by reference.
+"""
+import struct
+from demandload import *
+demandload(globals(), "util")
+
+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)
+

mercurial/bundlerepo.py

@@ -1,219 +1,201 b''
 """
 bundlerepo.py - repository class for viewing uncompressed bundles
 
 This provides a read-only repository interface to bundles as if
 they were part of the actual repository.
 
 Copyright 2006 Benoit Boissinot <[e-mail]>
 
 This software may be used and distributed according to the terms
 of the GNU General Public License, incorporated herein by reference.
 """
 
 from node import *
 from i18n import gettext as _
 from demandload import demandload
-demandload(globals(), "util os struct")
+demandload(globals(), "changegroup util os struct")
 
 import localrepo, changelog, manifest, filelog, revlog
 
-def getchunk(source):
-    """get a chunk from a group"""
-    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
-
 class bundlerevlog(revlog.revlog):
     def __init__(self, opener, indexfile, datafile, bundlefile,
                  linkmapper=None):
         # How it works:
         # to retrieve a revision, we need to know the offset of
         # the revision in the bundlefile (an opened file).
         #
         # We store this offset in the index (start), to differentiate a
         # rev in the bundle and from a rev in the revlog, we check
         # len(index[r]). If the tuple is bigger than 7, it is a bundle
         # (it is bigger since we store the node to which the delta is)
         #
         revlog.revlog.__init__(self, opener, indexfile, datafile)
         self.bundlefile = bundlefile
-        def genchunk():
-            while 1:
+        def chunkpositer():
+            for chunk in changegroup.chunkiter(bundlefile):
                 pos = bundlefile.tell()
-                chunk = getchunk(bundlefile)
-                if not chunk:
-                    break
-                yield chunk, pos + 4 # XXX struct.calcsize(">l") == 4
+                yield chunk, pos - len(chunk)
         n = self.count()
         prev = None
-        for chunk, start in genchunk():
+        for chunk, start in chunkpositer():
             size = len(chunk)
             if size < 80:
                 raise util.Abort("invalid changegroup")
             start += 80
             size -= 80
             node, p1, p2, cs = struct.unpack("20s20s20s20s", chunk[:80])
             if node in self.nodemap:
                 prev = node
                 continue
             for p in (p1, p2):
                 if not p in self.nodemap:
                     raise RevlogError(_("unknown parent %s") % short(p1))
             if linkmapper is None:
                 link = n
             else:
                 link = linkmapper(cs)
 
             if not prev:
                 prev = p1
             # start, size, base is not used, link, p1, p2, delta ref
             e = (start, size, None, link, p1, p2, node, prev)
             self.index.append(e)
             self.nodemap[node] = n
             prev = node
             n += 1
 
     def bundle(self, rev):
         """is rev from the bundle"""
         if rev < 0:
             return False
         return len(self.index[rev]) > 7
     def bundlebase(self, rev): return self.index[rev][7]
     def chunk(self, rev):
         # Warning: in case of bundle, the diff is against bundlebase,
         # not against rev - 1
         # XXX: could use some caching
         if not self.bundle(rev):
             return revlog.revlog.chunk(self, rev)
         self.bundlefile.seek(self.start(rev))
         return self.bundlefile.read(self.length(rev))
 
     def revdiff(self, rev1, rev2):
         """return or calculate a delta between two revisions"""
         if self.bundle(rev1) and self.bundle(rev2):
             # hot path for bundle
             revb = self.rev(self.bundlebase(rev2))
             if revb == rev1:
                 return self.chunk(rev2)
         elif not self.bundle(rev1) and not self.bundle(rev2):
             return revlog.revlog.chunk(self, rev1, rev2)
 
         return self.diff(self.revision(self.node(rev1)),
                          self.revision(self.node(rev2)))
 
     def revision(self, node):
         """return an uncompressed revision of a given"""
         if node == nullid: return ""
 
         text = None
         chain = []
         iter_node = node
         rev = self.rev(iter_node)
         # reconstruct the revision if it is from a changegroup
         while self.bundle(rev):
             if self.cache and self.cache[0] == iter_node:
                 text = self.cache[2]
                 break
             chain.append(rev)
             iter_node = self.bundlebase(rev)
             rev = self.rev(iter_node)
         if text is None:
             text = revlog.revlog.revision(self, iter_node)
 
         while chain:
             delta = self.chunk(chain.pop())
             text = self.patches(text, [delta])
 
         p1, p2 = self.parents(node)
         if node != revlog.hash(text, p1, p2):
             raise RevlogError(_("integrity check failed on %s:%d")
                           % (self.datafile, self.rev(node)))
 
         self.cache = (node, rev, text)
         return text
 
     def addrevision(self, text, transaction, link, p1=None, p2=None, d=None):
         raise NotImplementedError
     def addgroup(self, revs, linkmapper, transaction, unique=0):
         raise NotImplementedError
     def strip(self, rev, minlink):
         raise NotImplementedError
     def checksize(self):
         raise NotImplementedError
 
 class bundlechangelog(bundlerevlog, changelog.changelog):
     def __init__(self, opener, bundlefile):
         changelog.changelog.__init__(self, opener)
         bundlerevlog.__init__(self, opener, "00changelog.i", "00changelog.d",
                               bundlefile)
 
 class bundlemanifest(bundlerevlog, manifest.manifest):
     def __init__(self, opener, bundlefile, linkmapper):
         manifest.manifest.__init__(self, opener)
         bundlerevlog.__init__(self, opener, self.indexfile, self.datafile,
                               bundlefile, linkmapper)
 
 class bundlefilelog(bundlerevlog, filelog.filelog):
     def __init__(self, opener, path, bundlefile, linkmapper):
         filelog.filelog.__init__(self, opener, path)
         bundlerevlog.__init__(self, opener, self.indexfile, self.datafile,
                               bundlefile, linkmapper)
 
 class bundlerepository(localrepo.localrepository):
     def __init__(self, ui, path, bundlename):
         localrepo.localrepository.__init__(self, ui, path)
         f = open(bundlename, "rb")
         s = os.fstat(f.fileno())
         self.bundlefile = f
         header = self.bundlefile.read(6)
         if not header.startswith("HG"):
             raise util.Abort(_("%s: not a Mercurial bundle file") % bundlename)
         elif not header.startswith("HG10"):
             raise util.Abort(_("%s: unknown bundle version") % bundlename)
         elif header == "HG10BZ":
             raise util.Abort(_("%s: compressed bundle not supported")
                              % bundlename)
         elif header == "HG10UN":
             # uncompressed bundle supported
             pass
         else:
             raise util.Abort(_("%s: unknown bundle compression type")
                              % bundlename)
         self.changelog = bundlechangelog(self.opener, self.bundlefile)
         self.manifest = bundlemanifest(self.opener, self.bundlefile,
                                        self.changelog.rev)
         # dict with the mapping 'filename' -> position in the bundle
         self.bundlefilespos = {}
         while 1:
-                f = getchunk(self.bundlefile)
-                if not f:
-                    break
-                self.bundlefilespos[f] = self.bundlefile.tell()
-                while getchunk(self.bundlefile):
-                    pass
+            f = changegroup.getchunk(self.bundlefile)
+            if not f:
+                break
+            self.bundlefilespos[f] = self.bundlefile.tell()
+            for c in changegroup.chunkiter(self.bundlefile):
+                pass
 
     def dev(self):
         return -1
 
     def file(self, f):
         if f[0] == '/':
             f = f[1:]
         if f in self.bundlefilespos:
             self.bundlefile.seek(self.bundlefilespos[f])
             return bundlefilelog(self.opener, f, self.bundlefile,
                                  self.changelog.rev)
         else:
             return filelog.filelog(self.opener, f)
 
     def close(self):
         """Close assigned bundle file immediately."""
         self.bundlefile.close()

mercurial/commands.py

@@ -1,3298 +1,3305 b''
 # commands.py - command processing for mercurial
 #
 # Copyright 2005 Matt Mackall <[e-mail]>
 #
 # This software may be used and distributed according to the terms
 # of the GNU General Public License, incorporated herein by reference.
 
 from demandload import demandload
 from node import *
 from i18n import gettext as _
 demandload(globals(), "os re sys signal shutil imp urllib pdb")
 demandload(globals(), "fancyopts ui hg util lock revlog templater bundlerepo")
 demandload(globals(), "fnmatch hgweb mdiff random signal tempfile time")
 demandload(globals(), "traceback errno socket version struct atexit sets bz2")
+demandload(globals(), "changegroup")
 
 class UnknownCommand(Exception):
     """Exception raised if command is not in the command table."""
 class AmbiguousCommand(Exception):
     """Exception raised if command shortcut matches more than one command."""
 
 def filterfiles(filters, files):
     l = [x for x in files if x in filters]
 
     for t in filters:
         if t and t[-1] != "/":
             t += "/"
         l += [x for x in files if x.startswith(t)]
     return l
 
 def relpath(repo, args):
     cwd = repo.getcwd()
     if cwd:
         return [util.normpath(os.path.join(cwd, x)) for x in args]
     return args
 
 def matchpats(repo, pats=[], opts={}, head=''):
     cwd = repo.getcwd()
     if not pats and cwd:
         opts['include'] = [os.path.join(cwd, i) for i in opts['include']]
         opts['exclude'] = [os.path.join(cwd, x) for x in opts['exclude']]
         cwd = ''
     return util.cmdmatcher(repo.root, cwd, pats or ['.'], opts.get('include'),
                            opts.get('exclude'), head)
 
 def makewalk(repo, pats, opts, node=None, head=''):
     files, matchfn, anypats = matchpats(repo, pats, opts, head)
     exact = dict(zip(files, files))
     def walk():
         for src, fn in repo.walk(node=node, files=files, match=matchfn):
             yield src, fn, util.pathto(repo.getcwd(), fn), fn in exact
     return files, matchfn, walk()
 
 def walk(repo, pats, opts, node=None, head=''):
     files, matchfn, results = makewalk(repo, pats, opts, node, head)
     for r in results:
         yield r
 
 def walkchangerevs(ui, repo, pats, opts):
     '''Iterate over files and the revs they changed in.
 
     Callers most commonly need to iterate backwards over the history
     it is interested in.  Doing so has awful (quadratic-looking)
     performance, so we use iterators in a "windowed" way.
 
     We walk a window of revisions in the desired order.  Within the
     window, we first walk forwards to gather data, then in the desired
     order (usually backwards) to display it.
 
     This function returns an (iterator, getchange, matchfn) tuple.  The
     getchange function returns the changelog entry for a numeric
     revision.  The iterator yields 3-tuples.  They will be of one of
     the following forms:
 
     "window", incrementing, lastrev: stepping through a window,
     positive if walking forwards through revs, last rev in the
     sequence iterated over - use to reset state for the current window
 
     "add", rev, fns: out-of-order traversal of the given file names
     fns, which changed during revision rev - use to gather data for
     possible display
 
     "iter", rev, None: in-order traversal of the revs earlier iterated
     over with "add" - use to display data'''
 
     def increasing_windows(start, end, windowsize=8, sizelimit=512):
         if start < end:
             while start < end:
                 yield start, min(windowsize, end-start)
                 start += windowsize
                 if windowsize < sizelimit:
                     windowsize *= 2
         else:
             while start > end:
                 yield start, min(windowsize, start-end-1)
                 start -= windowsize
                 if windowsize < sizelimit:
                     windowsize *= 2
 
 
     files, matchfn, anypats = matchpats(repo, pats, opts)
 
     if repo.changelog.count() == 0:
         return [], False, matchfn
 
     revs = map(int, revrange(ui, repo, opts['rev'] or ['tip:0']))
     wanted = {}
     slowpath = anypats
     fncache = {}
 
     chcache = {}
     def getchange(rev):
         ch = chcache.get(rev)
         if ch is None:
             chcache[rev] = ch = repo.changelog.read(repo.lookup(str(rev)))
         return ch
 
     if not slowpath and not files:
         # No files, no patterns.  Display all revs.
         wanted = dict(zip(revs, revs))
     if not slowpath:
         # Only files, no patterns.  Check the history of each file.
         def filerevgen(filelog):
             for i, window in increasing_windows(filelog.count()-1, -1):
                 revs = []
                 for j in xrange(i - window, i + 1):
                     revs.append(filelog.linkrev(filelog.node(j)))
                 revs.reverse()
                 for rev in revs:
                     yield rev
 
         minrev, maxrev = min(revs), max(revs)
         for file_ in files:
             filelog = repo.file(file_)
             # A zero count may be a directory or deleted file, so
             # try to find matching entries on the slow path.
             if filelog.count() == 0:
                 slowpath = True
                 break
             for rev in filerevgen(filelog):
                 if rev <= maxrev:
                     if rev < minrev:
                         break
                     fncache.setdefault(rev, [])
                     fncache[rev].append(file_)
                     wanted[rev] = 1
     if slowpath:
         # The slow path checks files modified in every changeset.
         def changerevgen():
             for i, window in increasing_windows(repo.changelog.count()-1, -1):
                 for j in xrange(i - window, i + 1):
                     yield j, getchange(j)[3]
 
         for rev, changefiles in changerevgen():
             matches = filter(matchfn, changefiles)
             if matches:
                 fncache[rev] = matches
                 wanted[rev] = 1
 
     def iterate():
         for i, window in increasing_windows(0, len(revs)):
             yield 'window', revs[0] < revs[-1], revs[-1]
             nrevs = [rev for rev in revs[i:i+window]
                      if rev in wanted]
             srevs = list(nrevs)
             srevs.sort()
             for rev in srevs:
                 fns = fncache.get(rev) or filter(matchfn, getchange(rev)[3])
                 yield 'add', rev, fns
             for rev in nrevs:
                 yield 'iter', rev, None
     return iterate(), getchange, matchfn
 
 revrangesep = ':'
 
 def revrange(ui, repo, revs, revlog=None):
     """Yield revision as strings from a list of revision specifications."""
     if revlog is None:
         revlog = repo.changelog
     revcount = revlog.count()
     def fix(val, defval):
         if not val:
             return defval
         try:
             num = int(val)
             if str(num) != val:
                 raise ValueError
             if num < 0:
                 num += revcount
             if num < 0:
                 num = 0
             elif num >= revcount:
                 raise ValueError
         except ValueError:
             try:
                 num = repo.changelog.rev(repo.lookup(val))
             except KeyError:
                 try:
                     num = revlog.rev(revlog.lookup(val))
                 except KeyError:
                     raise util.Abort(_('invalid revision identifier %s'), val)
         return num
     seen = {}
     for spec in revs:
         if spec.find(revrangesep) >= 0:
             start, end = spec.split(revrangesep, 1)
             start = fix(start, 0)
             end = fix(end, revcount - 1)
             step = start > end and -1 or 1
             for rev in xrange(start, end+step, step):
                 if rev in seen:
                     continue
                 seen[rev] = 1
                 yield str(rev)
         else:
             rev = fix(spec, None)
             if rev in seen:
                 continue
             seen[rev] = 1
             yield str(rev)
 
 def make_filename(repo, r, pat, node=None,
                   total=None, seqno=None, revwidth=None, pathname=None):
     node_expander = {
         'H': lambda: hex(node),
         'R': lambda: str(r.rev(node)),
         'h': lambda: short(node),
         }
     expander = {
         '%': lambda: '%',
         'b': lambda: os.path.basename(repo.root),
         }
 
     try:
         if node:
             expander.update(node_expander)
         if node and revwidth is not None:
             expander['r'] = lambda: str(r.rev(node)).zfill(revwidth)
         if total is not None:
             expander['N'] = lambda: str(total)
         if seqno is not None:
             expander['n'] = lambda: str(seqno)
         if total is not None and seqno is not None:
             expander['n'] = lambda:str(seqno).zfill(len(str(total)))
         if pathname is not None:
             expander['s'] = lambda: os.path.basename(pathname)
             expander['d'] = lambda: os.path.dirname(pathname) or '.'
             expander['p'] = lambda: pathname
 
         newname = []
         patlen = len(pat)
         i = 0
         while i < patlen:
             c = pat[i]
             if c == '%':
                 i += 1
                 c = pat[i]
                 c = expander[c]()
             newname.append(c)
             i += 1
         return ''.join(newname)
     except KeyError, inst:
         raise util.Abort(_("invalid format spec '%%%s' in output file name"),
                     inst.args[0])
 
 def make_file(repo, r, pat, node=None,
               total=None, seqno=None, revwidth=None, mode='wb', pathname=None):
     if not pat or pat == '-':
         return 'w' in mode and sys.stdout or sys.stdin
     if hasattr(pat, 'write') and 'w' in mode:
         return pat
     if hasattr(pat, 'read') and 'r' in mode:
         return pat
     return open(make_filename(repo, r, pat, node, total, seqno, revwidth,
                               pathname),
                 mode)
 
 def write_bundle(cg, filename=None, compress=True):
     """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.
     """
     class nocompress(object):
         def compress(self, x):
             return x
         def flush(self):
             return ""
 
     fh = None
     cleanup = None
     try:
         if filename:
             if os.path.exists(filename):
                 raise util.Abort(_("file '%s' already exists"), filename)
             fh = open(filename, "wb")
         else:
             fd, filename = tempfile.mkstemp(suffix=".hg", prefix="hg-bundle-")
             fh = os.fdopen(fd, "wb")
         cleanup = filename
 
         if compress:
             fh.write("HG10")
             z = bz2.BZ2Compressor(9)
         else:
             fh.write("HG10UN")
             z = nocompress()
-        while 1:
-            chunk = cg.read(4096)
-            if not chunk:
-                break
-            fh.write(z.compress(chunk))
+        # 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 changegroup.chunkiter(cg):
+                empty = False
+                fh.write(z.compress(changegroup.genchunk(chunk)))
+            fh.write(z.compress(changegroup.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 dodiff(fp, ui, repo, node1, node2, files=None, match=util.always,
            changes=None, text=False, opts={}):
     if not node1:
         node1 = repo.dirstate.parents()[0]
     # reading the data for node1 early allows it to play nicely
     # with repo.changes and the revlog cache.
     change = repo.changelog.read(node1)
     mmap = repo.manifest.read(change[0])
     date1 = util.datestr(change[2])
 
     if not changes:
         changes = repo.changes(node1, node2, files, match=match)
     modified, added, removed, deleted, unknown = changes
     if files:
         modified, added, removed = map(lambda x: filterfiles(files, x),
                                        (modified, added, removed))
 
     if not modified and not added and not removed:
         return
 
     if node2:
         change = repo.changelog.read(node2)
         mmap2 = repo.manifest.read(change[0])
         date2 = util.datestr(change[2])
         def read(f):
             return repo.file(f).read(mmap2[f])
     else:
         date2 = util.datestr()
         def read(f):
             return repo.wread(f)
 
     if ui.quiet:
         r = None
     else:
         hexfunc = ui.verbose and hex or short
         r = [hexfunc(node) for node in [node1, node2] if node]
 
     diffopts = ui.diffopts()
     showfunc = opts.get('show_function') or diffopts['showfunc']
     ignorews = opts.get('ignore_all_space') or diffopts['ignorews']
     for f in modified:
         to = None
         if f in mmap:
             to = repo.file(f).read(mmap[f])
         tn = read(f)
         fp.write(mdiff.unidiff(to, date1, tn, date2, f, r, text=text,
                                showfunc=showfunc, ignorews=ignorews))
     for f in added:
         to = None
         tn = read(f)
         fp.write(mdiff.unidiff(to, date1, tn, date2, f, r, text=text,
                                showfunc=showfunc, ignorews=ignorews))
     for f in removed:
         to = repo.file(f).read(mmap[f])
         tn = None
         fp.write(mdiff.unidiff(to, date1, tn, date2, f, r, text=text,
                                showfunc=showfunc, ignorews=ignorews))
 
 def trimuser(ui, name, rev, revcache):
     """trim the name of the user who committed a change"""
     user = revcache.get(rev)
     if user is None:
         user = revcache[rev] = ui.shortuser(name)
     return user
 
 class changeset_templater(object):
     '''use templater module to format changeset information.'''
 
     def __init__(self, ui, repo, mapfile):
         self.t = templater.templater(mapfile, templater.common_filters,
                                      cache={'parent': '{rev}:{node|short} ',
                                             'manifest': '{rev}:{node|short}'})
         self.ui = ui
         self.repo = repo
 
     def use_template(self, t):
         '''set template string to use'''
         self.t.cache['changeset'] = t
 
     def write(self, thing):
         '''write expanded template.
         uses in-order recursive traverse of iterators.'''
         for t in thing:
             if hasattr(t, '__iter__'):
                 self.write(t)
             else:
                 self.ui.write(t)
 
     def show(self, rev=0, changenode=None, brinfo=None):
         '''show a single changeset or file revision'''
         log = self.repo.changelog
         if changenode is None:
             changenode = log.node(rev)
         elif not rev:
             rev = log.rev(changenode)
 
         changes = log.read(changenode)
 
         def showlist(name, values, plural=None, **args):
             '''expand set of values.
             name is name of key in template map.
             values is list of strings or dicts.
             plural is plural of name, if not simply name + 's'.
 
             expansion works like this, given name 'foo'.
 
             if values is empty, expand 'no_foos'.
 
             if 'foo' not in template map, return values as a string,
             joined by space.
 
             expand 'start_foos'.
 
             for each value, expand 'foo'. if 'last_foo' in template
             map, expand it instead of 'foo' for last key.
 
             expand 'end_foos'.
             '''
             if plural: names = plural
             else: names = name + 's'
             if not values:
                 noname = 'no_' + names
                 if noname in self.t:
                     yield self.t(noname, **args)
                 return
             if name not in self.t:
                 if isinstance(values[0], str):
                     yield ' '.join(values)
                 else:
                     for v in values:
                         yield dict(v, **args)
                 return
             startname = 'start_' + names
             if startname in self.t:
                 yield self.t(startname, **args)
             vargs = args.copy()
             def one(v, tag=name):
                 try:
                     vargs.update(v)
                 except (AttributeError, ValueError):
                     try:
                         for a, b in v:
                             vargs[a] = b
                     except ValueError:
                         vargs[name] = v
                 return self.t(tag, **vargs)
             lastname = 'last_' + name
             if lastname in self.t:
                 last = values.pop()
             else:
                 last = None
             for v in values:
                 yield one(v)
             if last is not None:
                 yield one(last, tag=lastname)
             endname = 'end_' + names
             if endname in self.t:
                 yield self.t(endname, **args)
 
         if brinfo:
             def showbranches(**args):
                 if changenode in brinfo:
                     for x in showlist('branch', brinfo[changenode],
                                       plural='branches', **args):
                         yield x
         else:
             showbranches = ''
 
         if self.ui.debugflag:
             def showmanifest(**args):
                 args = args.copy()
                 args.update(dict(rev=self.repo.manifest.rev(changes[0]),
                                  node=hex(changes[0])))
                 yield self.t('manifest', **args)
         else:
             showmanifest = ''
 
         def showparents(**args):
             parents = [[('rev', log.rev(p)), ('node', hex(p))]
                        for p in log.parents(changenode)
                        if self.ui.debugflag or p != nullid]
             if (not self.ui.debugflag and len(parents) == 1 and
                 parents[0][0][1] == rev - 1):
                 return
             for x in showlist('parent', parents, **args):
                 yield x
 
         def showtags(**args):
             for x in showlist('tag', self.repo.nodetags(changenode), **args):
                 yield x
 
         if self.ui.debugflag:
             files = self.repo.changes(log.parents(changenode)[0], changenode)
             def showfiles(**args):
                 for x in showlist('file', files[0], **args): yield x
             def showadds(**args):
                 for x in showlist('file_add', files[1], **args): yield x
             def showdels(**args):
                 for x in showlist('file_del', files[2], **args): yield x
         else:
             def showfiles(**args):
                 for x in showlist('file', changes[3], **args): yield x
             showadds = ''
             showdels = ''
 
         props = {
             'author': changes[1],
             'branches': showbranches,
             'date': changes[2],
             'desc': changes[4],
             'file_adds': showadds,
             'file_dels': showdels,
             'files': showfiles,
             'manifest': showmanifest,
             'node': hex(changenode),
             'parents': showparents,
             'rev': rev,
             'tags': showtags,
             }
 
         try:
             if self.ui.debugflag and 'changeset_debug' in self.t:
                 key = 'changeset_debug'
             elif self.ui.quiet and 'changeset_quiet' in self.t:
                 key = 'changeset_quiet'
             elif self.ui.verbose and 'changeset_verbose' in self.t:
                 key = 'changeset_verbose'
             else:
                 key = 'changeset'
             self.write(self.t(key, **props))
         except KeyError, inst:
             raise util.Abort(_("%s: no key named '%s'") % (self.t.mapfile,
                                                            inst.args[0]))
         except SyntaxError, inst:
             raise util.Abort(_('%s: %s') % (self.t.mapfile, inst.args[0]))
 
 class changeset_printer(object):
     '''show changeset information when templating not requested.'''
 
     def __init__(self, ui, repo):
         self.ui = ui
         self.repo = repo
 
     def show(self, rev=0, changenode=None, brinfo=None):
         '''show a single changeset or file revision'''
         log = self.repo.changelog
         if changenode is None:
             changenode = log.node(rev)
         elif not rev:
             rev = log.rev(changenode)
 
         if self.ui.quiet:
             self.ui.write("%d:%s\n" % (rev, short(changenode)))
             return
 
         changes = log.read(changenode)
         date = util.datestr(changes[2])
 
         parents = [(log.rev(p), self.ui.verbose and hex(p) or short(p))
                    for p in log.parents(changenode)
                    if self.ui.debugflag or p != nullid]
         if (not self.ui.debugflag and len(parents) == 1 and
             parents[0][0] == rev-1):
             parents = []
 
         if self.ui.verbose:
             self.ui.write(_("changeset:   %d:%s\n") % (rev, hex(changenode)))
         else:
             self.ui.write(_("changeset:   %d:%s\n") % (rev, short(changenode)))
 
         for tag in self.repo.nodetags(changenode):
             self.ui.status(_("tag:         %s\n") % tag)
         for parent in parents:
             self.ui.write(_("parent:      %d:%s\n") % parent)
 
         if brinfo and changenode in brinfo:
             br = brinfo[changenode]
             self.ui.write(_("branch:      %s\n") % " ".join(br))
 
         self.ui.debug(_("manifest:    %d:%s\n") %
                       (self.repo.manifest.rev(changes[0]), hex(changes[0])))
         self.ui.status(_("user:        %s\n") % changes[1])
         self.ui.status(_("date:        %s\n") % date)
 
         if self.ui.debugflag:
             files = self.repo.changes(log.parents(changenode)[0], changenode)
             for key, value in zip([_("files:"), _("files+:"), _("files-:")],
                                   files):
                 if value:
                     self.ui.note("%-12s %s\n" % (key, " ".join(value)))
         else:
             self.ui.note(_("files:       %s\n") % " ".join(changes[3]))
 
         description = changes[4].strip()
         if description:
             if self.ui.verbose:
                 self.ui.status(_("description:\n"))
                 self.ui.status(description)
                 self.ui.status("\n\n")
             else:
                 self.ui.status(_("summary:     %s\n") %
                                description.splitlines()[0])
         self.ui.status("\n")
 
 def show_changeset(ui, repo, opts):
     '''show one changeset.  uses template or regular display.  caller
     can pass in 'style' and 'template' options in opts.'''
 
     tmpl = opts.get('template')
     if tmpl:
         tmpl = templater.parsestring(tmpl, quoted=False)
     else:
         tmpl = ui.config('ui', 'logtemplate')
         if tmpl: tmpl = templater.parsestring(tmpl)
     mapfile = opts.get('style') or ui.config('ui', 'style')
     if tmpl or mapfile:
         if mapfile:
             if not os.path.isfile(mapfile):
                 mapname = templater.templatepath('map-cmdline.' + mapfile)
                 if not mapname: mapname = templater.templatepath(mapfile)
                 if mapname: mapfile = mapname
         try:
             t = changeset_templater(ui, repo, mapfile)
         except SyntaxError, inst:
             raise util.Abort(inst.args[0])
         if tmpl: t.use_template(tmpl)
         return t
     return changeset_printer(ui, repo)
 
 def show_version(ui):
     """output version and copyright information"""
     ui.write(_("Mercurial Distributed SCM (version %s)\n")
              % version.get_version())
     ui.status(_(
         "\nCopyright (C) 2005 Matt Mackall <[e-mail]>\n"
         "This is free software; see the source for copying conditions. "
         "There is NO\nwarranty; "
         "not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n"
     ))
 
 def help_(ui, cmd=None, with_version=False):
     """show help for a given command or all commands"""
     option_lists = []
     if cmd and cmd != 'shortlist':
         if with_version:
             show_version(ui)
             ui.write('\n')
         aliases, i = find(cmd)
         # synopsis
         ui.write("%s\n\n" % i[2])
 
         # description
         doc = i[0].__doc__
         if not doc:
             doc = _("(No help text available)")
         if ui.quiet:
             doc = doc.splitlines(0)[0]
         ui.write("%s\n" % doc.rstrip())
 
         if not ui.quiet:
             # aliases
             if len(aliases) > 1:
                 ui.write(_("\naliases: %s\n") % ', '.join(aliases[1:]))
 
             # options
             if i[1]:
                 option_lists.append(("options", i[1]))
 
     else:
         # program name
         if ui.verbose or with_version:
             show_version(ui)
         else:
             ui.status(_("Mercurial Distributed SCM\n"))
         ui.status('\n')
 
         # list of commands
         if cmd == "shortlist":
             ui.status(_('basic commands (use "hg help" '
                         'for the full list or option "-v" for details):\n\n'))
         elif ui.verbose:
             ui.status(_('list of commands:\n\n'))
         else:
             ui.status(_('list of commands (use "hg help -v" '
                         'to show aliases and global options):\n\n'))
 
         h = {}
         cmds = {}
         for c, e in table.items():
             f = c.split("|")[0]
             if cmd == "shortlist" and not f.startswith("^"):
                 continue
             f = f.lstrip("^")
             if not ui.debugflag and f.startswith("debug"):
                 continue
             doc = e[0].__doc__
             if not doc:
                 doc = _("(No help text available)")
             h[f] = doc.splitlines(0)[0].rstrip()
             cmds[f] = c.lstrip("^")
 
         fns = h.keys()
         fns.sort()
         m = max(map(len, fns))
         for f in fns:
             if ui.verbose:
                 commands = cmds[f].replace("|",", ")
                 ui.write(" %s:\n      %s\n"%(commands, h[f]))
             else:
                 ui.write(' %-*s   %s\n' % (m, f, h[f]))
 
     # global options
     if ui.verbose:
         option_lists.append(("global options", globalopts))
 
     # list all option lists
     opt_output = []
     for title, options in option_lists:
         opt_output.append(("\n%s:\n" % title, None))
         for shortopt, longopt, default, desc in options:
             opt_output.append(("%2s%s" % (shortopt and "-%s" % shortopt,
                                           longopt and " --%s" % longopt),
                                "%s%s" % (desc,
                                          default
                                          and _(" (default: %s)") % default
                                          or "")))
 
     if opt_output:
         opts_len = max([len(line[0]) for line in opt_output if line[1]])
         for first, second in opt_output:
             if second:
                 ui.write(" %-*s  %s\n" % (opts_len, first, second))
             else:
                 ui.write("%s\n" % first)
 
 # Commands start here, listed alphabetically
 
 def add(ui, repo, *pats, **opts):
     """add the specified files on the next commit
 
     Schedule files to be version controlled and added to the repository.
 
     The files will be added to the repository at the next commit.
 
     If no names are given, add all files in the repository.
     """
 
     names = []
     for src, abs, rel, exact in walk(repo, pats, opts):
         if exact:
             if ui.verbose:
                 ui.status(_('adding %s\n') % rel)
             names.append(abs)
         elif repo.dirstate.state(abs) == '?':
             ui.status(_('adding %s\n') % rel)
             names.append(abs)
     repo.add(names)
 
 def addremove(ui, repo, *pats, **opts):
     """add all new files, delete all missing files
 
     Add all new files and remove all missing files from the repository.
 
     New files are ignored if they match any of the patterns in .hgignore. As
     with add, these changes take effect at the next commit.
     """
     return addremove_lock(ui, repo, pats, opts)
 
 def addremove_lock(ui, repo, pats, opts, wlock=None):
     add, remove = [], []
     for src, abs, rel, exact in walk(repo, pats, opts):
         if src == 'f' and repo.dirstate.state(abs) == '?':
             add.append(abs)
             if ui.verbose or not exact:
                 ui.status(_('adding %s\n') % ((pats and rel) or abs))
         if repo.dirstate.state(abs) != 'r' and not os.path.exists(rel):
             remove.append(abs)
             if ui.verbose or not exact:
                 ui.status(_('removing %s\n') % ((pats and rel) or abs))
     repo.add(add, wlock=wlock)
     repo.remove(remove, wlock=wlock)
 
 def annotate(ui, repo, *pats, **opts):
     """show changeset information per file line
 
     List changes in files, showing the revision id responsible for each line
 
     This command is useful to discover who did a change or when a change took
     place.
 
     Without the -a option, annotate will avoid processing files it
     detects as binary. With -a, annotate will generate an annotation
     anyway, probably with undesirable results.
     """
     def getnode(rev):
         return short(repo.changelog.node(rev))
 
     ucache = {}
     def getname(rev):
         cl = repo.changelog.read(repo.changelog.node(rev))
         return trimuser(ui, cl[1], rev, ucache)
 
     dcache = {}
     def getdate(rev):
         datestr = dcache.get(rev)
         if datestr is None:
             cl = repo.changelog.read(repo.changelog.node(rev))
             datestr = dcache[rev] = util.datestr(cl[2])
         return datestr
 
     if not pats:
         raise util.Abort(_('at least one file name or pattern required'))
 
     opmap = [['user', getname], ['number', str], ['changeset', getnode],
              ['date', getdate]]
     if not opts['user'] and not opts['changeset'] and not opts['date']:
         opts['number'] = 1
 
     if opts['rev']:
         node = repo.changelog.lookup(opts['rev'])
     else:
         node = repo.dirstate.parents()[0]
     change = repo.changelog.read(node)
     mmap = repo.manifest.read(change[0])
 
     for src, abs, rel, exact in walk(repo, pats, opts, node=node):
         f = repo.file(abs)
         if not opts['text'] and util.binary(f.read(mmap[abs])):
             ui.write(_("%s: binary file\n") % ((pats and rel) or abs))
             continue
 
         lines = f.annotate(mmap[abs])
         pieces = []
 
         for o, f in opmap:
             if opts[o]:
                 l = [f(n) for n, dummy in lines]
                 if l:
                     m = max(map(len, l))
                     pieces.append(["%*s" % (m, x) for x in l])
 
         if pieces:
             for p, l in zip(zip(*pieces), lines):
                 ui.write("%s: %s" % (" ".join(p), l[1]))
 
 def bundle(ui, repo, fname, dest="default-push", **opts):
     """create a changegroup file
 
     Generate a compressed changegroup file collecting all changesets
     not found in the other repository.
 
     This file can then be transferred using conventional means and
     applied to another repository with the unbundle command. This is
     useful when native push and pull are not available or when
     exporting an entire repository is undesirable. The standard file
     extension is ".hg".
 
     Unlike import/export, this exactly preserves all changeset
     contents including permissions, rename data, and revision history.
     """
     dest = ui.expandpath(dest)
     other = hg.repository(ui, dest)
     o = repo.findoutgoing(other, force=opts['force'])
     cg = repo.changegroup(o, 'bundle')
     write_bundle(cg, fname)
 
 def cat(ui, repo, file1, *pats, **opts):
     """output the latest or given revisions of files
 
     Print the specified files as they were at the given revision.
     If no revision is given then the tip is used.
 
     Output may be to a file, in which case the name of the file is
     given using a format string.  The formatting rules are the same as
     for the export command, with the following additions:
 
     %s   basename of file being printed
     %d   dirname of file being printed, or '.' if in repo root
     %p   root-relative path name of file being printed
     """
     mf = {}
     rev = opts['rev']
     if rev:
         node = repo.lookup(rev)
     else:
         node = repo.changelog.tip()
     change = repo.changelog.read(node)
     mf = repo.manifest.read(change[0])
     for src, abs, rel, exact in walk(repo, (file1,) + pats, opts, node):
         r = repo.file(abs)
         n = mf[abs]
         fp = make_file(repo, r, opts['output'], node=n, pathname=abs)
         fp.write(r.read(n))
 
 def clone(ui, source, dest=None, **opts):
     """make a copy of an existing repository
 
     Create a copy of an existing repository in a new directory.
 
     If no destination directory name is specified, it defaults to the
     basename of the source.
 
     The location of the source is added to the new repository's
     .hg/hgrc file, as the default to be used for future pulls.
 
     For efficiency, hardlinks are used for cloning whenever the source
     and destination are on the same filesystem.  Some filesystems,
     such as AFS, implement hardlinking incorrectly, but do not report
     errors.  In these cases, use the --pull option to avoid
     hardlinking.
 
     See pull for valid source format details.
     """
     if dest is None:
         dest = os.path.basename(os.path.normpath(source))
 
     if os.path.exists(dest):
         raise util.Abort(_("destination '%s' already exists"), dest)
 
     dest = os.path.realpath(dest)
 
     class Dircleanup(object):
         def __init__(self, dir_):
             self.rmtree = shutil.rmtree
             self.dir_ = dir_
             os.mkdir(dir_)
         def close(self):
             self.dir_ = None
         def __del__(self):
             if self.dir_:
                 self.rmtree(self.dir_, True)
 
     if opts['ssh']:
         ui.setconfig("ui", "ssh", opts['ssh'])
     if opts['remotecmd']:
         ui.setconfig("ui", "remotecmd", opts['remotecmd'])
 
     source = ui.expandpath(source)
 
     d = Dircleanup(dest)
     abspath = source
     other = hg.repository(ui, source)
 
     copy = False
     if other.dev() != -1:
         abspath = os.path.abspath(source)
         if not opts['pull'] and not opts['rev']:
             copy = True
 
     if copy:
         try:
             # we use a lock here because if we race with commit, we
             # can end up with extra data in the cloned revlogs that's
             # not pointed to by changesets, thus causing verify to
             # fail
             l1 = other.lock()
         except lock.LockException:
             copy = False
 
     if copy:
         # we lock here to avoid premature writing to the target
         os.mkdir(os.path.join(dest, ".hg"))
         l2 = lock.lock(os.path.join(dest, ".hg", "lock"))
 
         files = "data 00manifest.d 00manifest.i 00changelog.d 00changelog.i"
         for f in files.split():
             src = os.path.join(source, ".hg", f)
             dst = os.path.join(dest, ".hg", f)
             try:
                 util.copyfiles(src, dst)
             except OSError, inst:
                 if inst.errno != errno.ENOENT:
                     raise
 
         repo = hg.repository(ui, dest)
 
     else:
         revs = None
         if opts['rev']:
             if not other.local():
                 error = _("clone -r not supported yet for remote repositories.")
                 raise util.Abort(error)
             else:
                 revs = [other.lookup(rev) for rev in opts['rev']]
         repo = hg.repository(ui, dest, create=1)
         repo.pull(other, heads = revs)
 
     f = repo.opener("hgrc", "w", text=True)
     f.write("[paths]\n")
     f.write("default = %s\n" % abspath)
     f.close()
 
     if not opts['noupdate']:
         update(repo.ui, repo)
 
     d.close()
 
 def commit(ui, repo, *pats, **opts):
     """commit the specified files or all outstanding changes
 
     Commit changes to the given files into the repository.
 
     If a list of files is omitted, all changes reported by "hg status"
     will be commited.
 
     The HGEDITOR or EDITOR environment variables are used to start an
     editor to add a commit comment.
     """
     message = opts['message']
     logfile = opts['logfile']
 
     if message and logfile:
         raise util.Abort(_('options --message and --logfile are mutually '
                            'exclusive'))
     if not message and logfile:
         try:
             if logfile == '-':
                 message = sys.stdin.read()
             else:
                 message = open(logfile).read()
         except IOError, inst:
             raise util.Abort(_("can't read commit message '%s': %s") %
                              (logfile, inst.strerror))
 
     if opts['addremove']:
         addremove(ui, repo, *pats, **opts)
     fns, match, anypats = matchpats(repo, pats, opts)
     if pats:
         modified, added, removed, deleted, unknown = (
             repo.changes(files=fns, match=match))
         files = modified + added + removed
     else:
         files = []
     try:
         repo.commit(files, message, opts['user'], opts['date'], match)
     except ValueError, inst:
         raise util.Abort(str(inst))
 
 def docopy(ui, repo, pats, opts, wlock):
     # called with the repo lock held
     cwd = repo.getcwd()
     errors = 0
     copied = []
     targets = {}
 
     def okaytocopy(abs, rel, exact):
         reasons = {'?': _('is not managed'),
                    'a': _('has been marked for add'),
                    'r': _('has been marked for remove')}
         state = repo.dirstate.state(abs)
         reason = reasons.get(state)
         if reason:
             if state == 'a':
                 origsrc = repo.dirstate.copied(abs)
                 if origsrc is not None:
                     return origsrc
             if exact:
                 ui.warn(_('%s: not copying - file %s\n') % (rel, reason))
         else:
             return abs
 
     def copy(origsrc, abssrc, relsrc, target, exact):
         abstarget = util.canonpath(repo.root, cwd, target)
         reltarget = util.pathto(cwd, abstarget)
         prevsrc = targets.get(abstarget)
         if prevsrc is not None:
             ui.warn(_('%s: not overwriting - %s collides with %s\n') %
                     (reltarget, abssrc, prevsrc))
             return
         if (not opts['after'] and os.path.exists(reltarget) or
             opts['after'] and repo.dirstate.state(abstarget) not in '?r'):
             if not opts['force']:
                 ui.warn(_('%s: not overwriting - file exists\n') %
                         reltarget)
                 return
             if not opts['after']:
                 os.unlink(reltarget)
         if opts['after']:
             if not os.path.exists(reltarget):
                 return
         else:
             targetdir = os.path.dirname(reltarget) or '.'
             if not os.path.isdir(targetdir):
                 os.makedirs(targetdir)
             try:
                 restore = repo.dirstate.state(abstarget) == 'r'
                 if restore:
                     repo.undelete([abstarget], wlock)
                 try:
                     shutil.copyfile(relsrc, reltarget)
                     shutil.copymode(relsrc, reltarget)
                     restore = False
                 finally:
                     if restore:
                         repo.remove([abstarget], wlock)
             except shutil.Error, inst:
                 raise util.Abort(str(inst))
             except IOError, inst:
                 if inst.errno == errno.ENOENT:
                     ui.warn(_('%s: deleted in working copy\n') % relsrc)
                 else:
                     ui.warn(_('%s: cannot copy - %s\n') %
                             (relsrc, inst.strerror))
                     errors += 1
                     return
         if ui.verbose or not exact:
             ui.status(_('copying %s to %s\n') % (relsrc, reltarget))
         targets[abstarget] = abssrc
         if abstarget != origsrc:
             repo.copy(origsrc, abstarget, wlock)
         copied.append((abssrc, relsrc, exact))
 
     def targetpathfn(pat, dest, srcs):
         if os.path.isdir(pat):
             abspfx = util.canonpath(repo.root, cwd, pat)
             if destdirexists:
                 striplen = len(os.path.split(abspfx)[0])
             else:
                 striplen = len(abspfx)
             if striplen:
                 striplen += len(os.sep)
             res = lambda p: os.path.join(dest, p[striplen:])
         elif destdirexists:
             res = lambda p: os.path.join(dest, os.path.basename(p))
         else:
             res = lambda p: dest
         return res
 
     def targetpathafterfn(pat, dest, srcs):
         if util.patkind(pat, None)[0]:
             # a mercurial pattern
             res = lambda p: os.path.join(dest, os.path.basename(p))
         else:
             abspfx = util.canonpath(repo.root, cwd, pat)
             if len(abspfx) < len(srcs[0][0]):
                 # A directory. Either the target path contains the last
                 # component of the source path or it does not.
                 def evalpath(striplen):
                     score = 0
                     for s in srcs:
                         t = os.path.join(dest, s[0][striplen:])
                         if os.path.exists(t):
                             score += 1
                     return score
 
                 striplen = len(abspfx)
                 if striplen:
                     striplen += len(os.sep)
                 if os.path.isdir(os.path.join(dest, os.path.split(abspfx)[1])):
                     score = evalpath(striplen)
                     striplen1 = len(os.path.split(abspfx)[0])
                     if striplen1:
                         striplen1 += len(os.sep)
                     if evalpath(striplen1) > score:
                         striplen = striplen1
                 res = lambda p: os.path.join(dest, p[striplen:])
             else:
                 # a file
                 if destdirexists:
                     res = lambda p: os.path.join(dest, os.path.basename(p))
                 else:
                     res = lambda p: dest
         return res
 
 
     pats = list(pats)
     if not pats:
         raise util.Abort(_('no source or destination specified'))
     if len(pats) == 1:
         raise util.Abort(_('no destination specified'))
     dest = pats.pop()
     destdirexists = os.path.isdir(dest)
     if (len(pats) > 1 or util.patkind(pats[0], None)[0]) and not destdirexists:
         raise util.Abort(_('with multiple sources, destination must be an '
                          'existing directory'))
     if opts['after']:
         tfn = targetpathafterfn
     else:
         tfn = targetpathfn
     copylist = []
     for pat in pats:
         srcs = []
         for tag, abssrc, relsrc, exact in walk(repo, [pat], opts):
             origsrc = okaytocopy(abssrc, relsrc, exact)
             if origsrc:
                 srcs.append((origsrc, abssrc, relsrc, exact))
         if not srcs:
             continue
         copylist.append((tfn(pat, dest, srcs), srcs))
     if not copylist:
         raise util.Abort(_('no files to copy'))
 
     for targetpath, srcs in copylist:
         for origsrc, abssrc, relsrc, exact in srcs:
             copy(origsrc, abssrc, relsrc, targetpath(abssrc), exact)
 
     if errors:
         ui.warn(_('(consider using --after)\n'))
     return errors, copied
 
 def copy(ui, repo, *pats, **opts):
     """mark files as copied for the next commit
 
     Mark dest as having copies of source files.  If dest is a
     directory, copies are put in that directory.  If dest is a file,
     there can only be one source.
 
     By default, this command copies the contents of files as they
     stand in the working directory.  If invoked with --after, the
     operation is recorded, but no copying is performed.
 
     This command takes effect in the next commit.
 
     NOTE: This command should be treated as experimental. While it
     should properly record copied files, this information is not yet
     fully used by merge, nor fully reported by log.
     """
     try:
         wlock = repo.wlock(0)
         errs, copied = docopy(ui, repo, pats, opts, wlock)
     except lock.LockHeld, inst:
         ui.warn(_("repository lock held by %s\n") % inst.args[0])
         errs = 1
     return errs
 
 def debugancestor(ui, index, rev1, rev2):
     """find the ancestor revision of two revisions in a given index"""
     r = revlog.revlog(util.opener(os.getcwd(), audit=False), index, "")
     a = r.ancestor(r.lookup(rev1), r.lookup(rev2))
     ui.write("%d:%s\n" % (r.rev(a), hex(a)))
 
 def debugcomplete(ui, cmd):
     """returns the completion list associated with the given command"""
     clist = findpossible(cmd).keys()
     clist.sort()
     ui.write("%s\n" % " ".join(clist))
 
 def debugrebuildstate(ui, repo, rev=None):
     """rebuild the dirstate as it would look like for the given revision"""
     if not rev:
         rev = repo.changelog.tip()
     else:
         rev = repo.lookup(rev)
     change = repo.changelog.read(rev)
     n = change[0]
     files = repo.manifest.readflags(n)
     wlock = repo.wlock()
     repo.dirstate.rebuild(rev, files.iteritems())
 
 def debugcheckstate(ui, repo):
     """validate the correctness of the current dirstate"""
     parent1, parent2 = repo.dirstate.parents()
     repo.dirstate.read()
     dc = repo.dirstate.map
     keys = dc.keys()
     keys.sort()
     m1n = repo.changelog.read(parent1)[0]
     m2n = repo.changelog.read(parent2)[0]
     m1 = repo.manifest.read(m1n)
     m2 = repo.manifest.read(m2n)
     errors = 0
     for f in dc:
         state = repo.dirstate.state(f)
         if state in "nr" and f not in m1:
             ui.warn(_("%s in state %s, but not in manifest1\n") % (f, state))
             errors += 1
         if state in "a" and f in m1:
             ui.warn(_("%s in state %s, but also in manifest1\n") % (f, state))
             errors += 1
         if state in "m" and f not in m1 and f not in m2:
             ui.warn(_("%s in state %s, but not in either manifest\n") %
                     (f, state))
             errors += 1
     for f in m1:
         state = repo.dirstate.state(f)
         if state not in "nrm":
             ui.warn(_("%s in manifest1, but listed as state %s") % (f, state))
             errors += 1
     if errors:
         error = _(".hg/dirstate inconsistent with current parent's manifest")
         raise util.Abort(error)
 
 def debugconfig(ui, repo):
     """show combined config settings from all hgrc files"""
     for section, name, value in ui.walkconfig():
         ui.write('%s.%s=%s\n' % (section, name, value))
 
 def debugsetparents(ui, repo, rev1, rev2=None):
     """manually set the parents of the current working directory
 
     This is useful for writing repository conversion tools, but should
     be used with care.
     """
 
     if not rev2:
         rev2 = hex(nullid)
 
     repo.dirstate.setparents(repo.lookup(rev1), repo.lookup(rev2))
 
 def debugstate(ui, repo):
     """show the contents of the current dirstate"""
     repo.dirstate.read()
     dc = repo.dirstate.map
     keys = dc.keys()
     keys.sort()
     for file_ in keys:
         ui.write("%c %3o %10d %s %s\n"
                  % (dc[file_][0], dc[file_][1] & 0777, dc[file_][2],
                     time.strftime("%x %X",
                                   time.localtime(dc[file_][3])), file_))
     for f in repo.dirstate.copies:
         ui.write(_("copy: %s -> %s\n") % (repo.dirstate.copies[f], f))
 
 def debugdata(ui, file_, rev):
     """dump the contents of an data file revision"""
     r = revlog.revlog(util.opener(os.getcwd(), audit=False),
                       file_[:-2] + ".i", file_)
     try:
         ui.write(r.revision(r.lookup(rev)))
     except KeyError:
         raise util.Abort(_('invalid revision identifier %s'), rev)
 
 def debugindex(ui, file_):
     """dump the contents of an index file"""
     r = revlog.revlog(util.opener(os.getcwd(), audit=False), file_, "")
     ui.write("   rev    offset  length   base linkrev" +
              " nodeid       p1           p2\n")
     for i in range(r.count()):
         e = r.index[i]
         ui.write("% 6d % 9d % 7d % 6d % 7d %s %s %s\n" % (
                 i, e[0], e[1], e[2], e[3],
             short(e[6]), short(e[4]), short(e[5])))
 
 def debugindexdot(ui, file_):
     """dump an index DAG as a .dot file"""
     r = revlog.revlog(util.opener(os.getcwd(), audit=False), file_, "")
     ui.write("digraph G {\n")
     for i in range(r.count()):
         e = r.index[i]
         ui.write("\t%d -> %d\n" % (r.rev(e[4]), i))
         if e[5] != nullid:
             ui.write("\t%d -> %d\n" % (r.rev(e[5]), i))
     ui.write("}\n")
 
 def debugrename(ui, repo, file, rev=None):
     """dump rename information"""
     r = repo.file(relpath(repo, [file])[0])
     if rev:
         try:
             # assume all revision numbers are for changesets
             n = repo.lookup(rev)
             change = repo.changelog.read(n)
             m = repo.manifest.read(change[0])
             n = m[relpath(repo, [file])[0]]
         except (hg.RepoError, KeyError):
             n = r.lookup(rev)
     else:
         n = r.tip()
     m = r.renamed(n)
     if m:
         ui.write(_("renamed from %s:%s\n") % (m[0], hex(m[1])))
     else:
         ui.write(_("not renamed\n"))
 
 def debugwalk(ui, repo, *pats, **opts):
     """show how files match on given patterns"""
     items = list(walk(repo, pats, opts))
     if not items:
         return
     fmt = '%%s  %%-%ds  %%-%ds  %%s' % (
         max([len(abs) for (src, abs, rel, exact) in items]),
         max([len(rel) for (src, abs, rel, exact) in items]))
     for src, abs, rel, exact in items:
         line = fmt % (src, abs, rel, exact and 'exact' or '')
         ui.write("%s\n" % line.rstrip())
 
 def diff(ui, repo, *pats, **opts):
     """diff repository (or selected files)
 
     Show differences between revisions for the specified files.
 
     Differences between files are shown using the unified diff format.
 
     When two revision arguments are given, then changes are shown
     between those revisions. If only one revision is specified then
     that revision is compared to the working directory, and, when no
     revisions are specified, the working directory files are compared
     to its parent.
 
     Without the -a option, diff will avoid generating diffs of files
     it detects as binary. With -a, diff will generate a diff anyway,
     probably with undesirable results.
     """
     node1, node2 = None, None
     revs = [repo.lookup(x) for x in opts['rev']]
 
     if len(revs) > 0:
         node1 = revs[0]
     if len(revs) > 1:
         node2 = revs[1]
     if len(revs) > 2:
         raise util.Abort(_("too many revisions to diff"))
 
     fns, matchfn, anypats = matchpats(repo, pats, opts)
 
     dodiff(sys.stdout, ui, repo, node1, node2, fns, match=matchfn,
            text=opts['text'], opts=opts)
 
 def doexport(ui, repo, changeset, seqno, total, revwidth, opts):
     node = repo.lookup(changeset)
     parents = [p for p in repo.changelog.parents(node) if p != nullid]
     if opts['switch_parent']:
         parents.reverse()
     prev = (parents and parents[0]) or nullid
     change = repo.changelog.read(node)
 
     fp = make_file(repo, repo.changelog, opts['output'],
                    node=node, total=total, seqno=seqno,
                    revwidth=revwidth)
     if fp != sys.stdout:
         ui.note("%s\n" % fp.name)
 
     fp.write("# HG changeset patch\n")
     fp.write("# User %s\n" % change[1])
     fp.write("# Node ID %s\n" % hex(node))
     fp.write("# Parent  %s\n" % hex(prev))
     if len(parents) > 1:
         fp.write("# Parent  %s\n" % hex(parents[1]))
     fp.write(change[4].rstrip())
     fp.write("\n\n")
 
     dodiff(fp, ui, repo, prev, node, text=opts['text'])
     if fp != sys.stdout:
         fp.close()
 
 def export(ui, repo, *changesets, **opts):
     """dump the header and diffs for one or more changesets
 
     Print the changeset header and diffs for one or more revisions.
 
     The information shown in the changeset header is: author,
     changeset hash, parent and commit comment.
 
     Output may be to a file, in which case the name of the file is
     given using a format string.  The formatting rules are as follows:
 
     %%   literal "%" character
     %H   changeset hash (40 bytes of hexadecimal)
     %N   number of patches being generated
     %R   changeset revision number
     %b   basename of the exporting repository
     %h   short-form changeset hash (12 bytes of hexadecimal)
     %n   zero-padded sequence number, starting at 1
     %r   zero-padded changeset revision number
 
     Without the -a option, export will avoid generating diffs of files
     it detects as binary. With -a, export will generate a diff anyway,
     probably with undesirable results.
 
     With the --switch-parent option, the diff will be against the second
     parent. It can be useful to review a merge.
     """
     if not changesets:
         raise util.Abort(_("export requires at least one changeset"))
     seqno = 0
     revs = list(revrange(ui, repo, changesets))
     total = len(revs)
     revwidth = max(map(len, revs))
     msg = len(revs) > 1 and _("Exporting patches:\n") or _("Exporting patch:\n")
     ui.note(msg)
     for cset in revs:
         seqno += 1
         doexport(ui, repo, cset, seqno, total, revwidth, opts)
 
 def forget(ui, repo, *pats, **opts):
     """don't add the specified files on the next commit
 
     Undo an 'hg add' scheduled for the next commit.
     """
     forget = []
     for src, abs, rel, exact in walk(repo, pats, opts):
         if repo.dirstate.state(abs) == 'a':
             forget.append(abs)
             if ui.verbose or not exact:
                 ui.status(_('forgetting %s\n') % ((pats and rel) or abs))
     repo.forget(forget)
 
 def grep(ui, repo, pattern, *pats, **opts):
     """search for a pattern in specified files and revisions
 
     Search revisions of files for a regular expression.
 
     This command behaves differently than Unix grep.  It only accepts
     Python/Perl regexps.  It searches repository history, not the
     working directory.  It always prints the revision number in which
     a match appears.
 
     By default, grep only prints output for the first revision of a
     file in which it finds a match.  To get it to print every revision
     that contains a change in match status ("-" for a match that
     becomes a non-match, or "+" for a non-match that becomes a match),
     use the --all flag.
     """
     reflags = 0
     if opts['ignore_case']:
         reflags |= re.I
     regexp = re.compile(pattern, reflags)
     sep, eol = ':', '\n'
     if opts['print0']:
         sep = eol = '\0'
 
     fcache = {}
     def getfile(fn):
         if fn not in fcache:
             fcache[fn] = repo.file(fn)
         return fcache[fn]
 
     def matchlines(body):
         begin = 0
         linenum = 0
         while True:
             match = regexp.search(body, begin)
             if not match:
                 break
             mstart, mend = match.span()
             linenum += body.count('\n', begin, mstart) + 1
             lstart = body.rfind('\n', begin, mstart) + 1 or begin
             lend = body.find('\n', mend)
             yield linenum, mstart - lstart, mend - lstart, body[lstart:lend]
             begin = lend + 1
 
     class linestate(object):
         def __init__(self, line, linenum, colstart, colend):
             self.line = line
             self.linenum = linenum
             self.colstart = colstart
             self.colend = colend
         def __eq__(self, other):
             return self.line == other.line
         def __hash__(self):
             return hash(self.line)
 
     matches = {}
     def grepbody(fn, rev, body):
         matches[rev].setdefault(fn, {})
         m = matches[rev][fn]
         for lnum, cstart, cend, line in matchlines(body):
             s = linestate(line, lnum, cstart, cend)
             m[s] = s
 
     # FIXME: prev isn't used, why ?
     prev = {}
     ucache = {}
     def display(fn, rev, states, prevstates):
         diff = list(sets.Set(states).symmetric_difference(sets.Set(prevstates)))
         diff.sort(lambda x, y: cmp(x.linenum, y.linenum))
         counts = {'-': 0, '+': 0}
         filerevmatches = {}
         for l in diff:
             if incrementing or not opts['all']:
                 change = ((l in prevstates) and '-') or '+'
                 r = rev
             else:
                 change = ((l in states) and '-') or '+'
                 r = prev[fn]
             cols = [fn, str(rev)]
             if opts['line_number']:
                 cols.append(str(l.linenum))
             if opts['all']:
                 cols.append(change)
             if opts['user']:
                 cols.append(trimuser(ui, getchange(rev)[1], rev,
                                                   ucache))
             if opts['files_with_matches']:
                 c = (fn, rev)
                 if c in filerevmatches:
                     continue
                 filerevmatches[c] = 1
             else:
                 cols.append(l.line)
             ui.write(sep.join(cols), eol)
             counts[change] += 1
         return counts['+'], counts['-']
 
     fstate = {}
     skip = {}
     changeiter, getchange, matchfn = walkchangerevs(ui, repo, pats, opts)
     count = 0
     incrementing = False
     for st, rev, fns in changeiter:
         if st == 'window':
             incrementing = rev
             matches.clear()
         elif st == 'add':
             change = repo.changelog.read(repo.lookup(str(rev)))
             mf = repo.manifest.read(change[0])
             matches[rev] = {}
             for fn in fns:
                 if fn in skip:
                     continue
                 fstate.setdefault(fn, {})
                 try:
                     grepbody(fn, rev, getfile(fn).read(mf[fn]))
                 except KeyError:
                     pass
         elif st == 'iter':
             states = matches[rev].items()
             states.sort()
             for fn, m in states:
                 if fn in skip:
                     continue
                 if incrementing or not opts['all'] or fstate[fn]:
                     pos, neg = display(fn, rev, m, fstate[fn])
                     count += pos + neg
                     if pos and not opts['all']:
                         skip[fn] = True
                 fstate[fn] = m
                 prev[fn] = rev
 
     if not incrementing:
         fstate = fstate.items()
         fstate.sort()
         for fn, state in fstate:
             if fn in skip:
                 continue
             display(fn, rev, {}, state)
     return (count == 0 and 1) or 0
 
 def heads(ui, repo, **opts):
     """show current repository heads
 
     Show all repository head changesets.
 
     Repository "heads" are changesets that don't have children
     changesets. They are where development generally takes place and
     are the usual targets for update and merge operations.
     """
     if opts['rev']:
         heads = repo.heads(repo.lookup(opts['rev']))
     else:
         heads = repo.heads()
     br = None
     if opts['branches']:
         br = repo.branchlookup(heads)
     displayer = show_changeset(ui, repo, opts)
     for n in heads:
         displayer.show(changenode=n, brinfo=br)
 
 def identify(ui, repo):
     """print information about the working copy
 
     Print a short summary of the current state of the repo.
 
     This summary identifies the repository state using one or two parent
     hash identifiers, followed by a "+" if there are uncommitted changes
     in the working directory, followed by a list of tags for this revision.
     """
     parents = [p for p in repo.dirstate.parents() if p != nullid]
     if not parents:
         ui.write(_("unknown\n"))
         return
 
     hexfunc = ui.verbose and hex or short
     modified, added, removed, deleted, unknown = repo.changes()
     output = ["%s%s" %
               ('+'.join([hexfunc(parent) for parent in parents]),
               (modified or added or removed or deleted) and "+" or "")]
 
     if not ui.quiet:
         # multiple tags for a single parent separated by '/'
         parenttags = ['/'.join(tags)
                       for tags in map(repo.nodetags, parents) if tags]
         # tags for multiple parents separated by ' + '
         if parenttags:
             output.append(' + '.join(parenttags))
 
     ui.write("%s\n" % ' '.join(output))
 
 def import_(ui, repo, patch1, *patches, **opts):
     """import an ordered set of patches
 
     Import a list of patches and commit them individually.
 
     If there are outstanding changes in the working directory, import
     will abort unless given the -f flag.
 
     If a patch looks like a mail message (its first line starts with
     "From " or looks like an RFC822 header), it will not be applied
     unless the -f option is used.  The importer neither parses nor
     discards mail headers, so use -f only to override the "mailness"
     safety check, not to import a real mail message.
     """
     patches = (patch1,) + patches
 
     if not opts['force']:
         modified, added, removed, deleted, unknown = repo.changes()
         if modified or added or removed or deleted:
             raise util.Abort(_("outstanding uncommitted changes"))
 
     d = opts["base"]
     strip = opts["strip"]
 
     mailre = re.compile(r'(?:From |[\w-]+:)')
 
     # attempt to detect the start of a patch
     # (this heuristic is borrowed from quilt)
     diffre = re.compile(r'(?:Index:[ \t]|diff[ \t]|RCS file: |' +
                         'retrieving revision [0-9]+(\.[0-9]+)*$|' +
                         '(---|\*\*\*)[ \t])')
 
     for patch in patches:
         ui.status(_("applying %s\n") % patch)
         pf = os.path.join(d, patch)
 
         message = []
         user = None
         hgpatch = False
         for line in file(pf):
             line = line.rstrip()
             if (not message and not hgpatch and
                    mailre.match(line) and not opts['force']):
                 if len(line) > 35:
                     line = line[:32] + '...'
                 raise util.Abort(_('first line looks like a '
                                    'mail header: ') + line)
             if diffre.match(line):
                 break
             elif hgpatch:
                 # parse values when importing the result of an hg export
                 if line.startswith("# User "):
                     user = line[7:]
                     ui.debug(_('User: %s\n') % user)
                 elif not line.startswith("# ") and line:
                     message.append(line)
                     hgpatch = False
             elif line == '# HG changeset patch':
                 hgpatch = True
                 message = []       # We may have collected garbage
             else:
                 message.append(line)
 
         # make sure message isn't empty
         if not message:
             message = _("imported patch %s\n") % patch
         else:
             message = "%s\n" % '\n'.join(message)
         ui.debug(_('message:\n%s\n') % message)
 
         files = util.patch(strip, pf, ui)
 
         if len(files) > 0:
             addremove(ui, repo, *files)
         repo.commit(files, message, user)
 
 def incoming(ui, repo, source="default", **opts):
     """show new changesets found in source
 
     Show new changesets found in the specified path/URL or the default
     pull location. These are the changesets that would be pulled if a pull
     was requested.
 
     For remote repository, using --bundle avoids downloading the changesets
     twice if the incoming is followed by a pull.
 
     See pull for valid source format details.
     """
     source = ui.expandpath(source)
     if opts['ssh']:
         ui.setconfig("ui", "ssh", opts['ssh'])
     if opts['remotecmd']:
         ui.setconfig("ui", "remotecmd", opts['remotecmd'])
 
     other = hg.repository(ui, source)
     incoming = repo.findincoming(other, force=opts["force"])
     if not incoming:
         return
 
     cleanup = None
     try:
         fname = opts["bundle"]
         if fname or not other.local():
             # create a bundle (uncompressed if other repo is not local)
             cg = other.changegroup(incoming, "incoming")
             fname = cleanup = write_bundle(cg, fname, compress=other.local())
             # keep written bundle?
             if opts["bundle"]:
                 cleanup = None
             if not other.local():
                 # use the created uncompressed bundlerepo
                 other = bundlerepo.bundlerepository(ui, repo.root, fname)
 
         o = other.changelog.nodesbetween(incoming)[0]
         if opts['newest_first']:
             o.reverse()
         displayer = show_changeset(ui, other, opts)
         for n in o:
             parents = [p for p in other.changelog.parents(n) if p != nullid]
             if opts['no_merges'] and len(parents) == 2:
                 continue
             displayer.show(changenode=n)
             if opts['patch']:
                 prev = (parents and parents[0]) or nullid
                 dodiff(ui, ui, other, prev, n)
                 ui.write("\n")
     finally:
         if hasattr(other, 'close'):
             other.close()
         if cleanup:
             os.unlink(cleanup)
 
 def init(ui, dest="."):
     """create a new repository in the given directory
 
     Initialize a new repository in the given directory.  If the given
     directory does not exist, it is created.
 
     If no directory is given, the current directory is used.
     """
     if not os.path.exists(dest):
         os.mkdir(dest)
     hg.repository(ui, dest, create=1)
 
 def locate(ui, repo, *pats, **opts):
     """locate files matching specific patterns
 
     Print all files under Mercurial control whose names match the
     given patterns.
 
     This command searches the current directory and its
     subdirectories.  To search an entire repository, move to the root
     of the repository.
 
     If no patterns are given to match, this command prints all file
     names.
 
     If you want to feed the output of this command into the "xargs"
     command, use the "-0" option to both this command and "xargs".
     This will avoid the problem of "xargs" treating single filenames
     that contain white space as multiple filenames.
     """
     end = opts['print0'] and '\0' or '\n'
     rev = opts['rev']
     if rev:
         node = repo.lookup(rev)
     else:
         node = None
 
     for src, abs, rel, exact in walk(repo, pats, opts, node=node,
                                      head='(?:.*/|)'):
         if not node and repo.dirstate.state(abs) == '?':
             continue
         if opts['fullpath']:
             ui.write(os.path.join(repo.root, abs), end)
         else:
             ui.write(((pats and rel) or abs), end)
 
 def log(ui, repo, *pats, **opts):
     """show revision history of entire repository or files
 
     Print the revision history of the specified files or the entire project.
 
     By default this command outputs: changeset id and hash, tags,
     non-trivial parents, user, date and time, and a summary for each
     commit. When the -v/--verbose switch is used, the list of changed
     files and full commit message is shown.
     """
     class dui(object):
         # Implement and delegate some ui protocol.  Save hunks of
         # output for later display in the desired order.
         def __init__(self, ui):
             self.ui = ui
             self.hunk = {}
         def bump(self, rev):
             self.rev = rev
             self.hunk[rev] = []
         def note(self, *args):
             if self.verbose:
                 self.write(*args)
         def status(self, *args):
             if not self.quiet:
                 self.write(*args)
         def write(self, *args):
             self.hunk[self.rev].append(args)
         def debug(self, *args):
             if self.debugflag:
                 self.write(*args)
         def __getattr__(self, key):
             return getattr(self.ui, key)
 
     changeiter, getchange, matchfn = walkchangerevs(ui, repo, pats, opts)
 
     if opts['limit']:
         try:
             limit = int(opts['limit'])
         except ValueError:
             raise util.Abort(_('limit must be a positive integer'))
         if limit <= 0: raise util.Abort(_('limit must be positive'))
     else:
         limit = sys.maxint
     count = 0
 
     displayer = show_changeset(ui, repo, opts)
     for st, rev, fns in changeiter:
         if st == 'window':
             du = dui(ui)
             displayer.ui = du
         elif st == 'add':
             du.bump(rev)
             changenode = repo.changelog.node(rev)
             parents = [p for p in repo.changelog.parents(changenode)
                        if p != nullid]
             if opts['no_merges'] and len(parents) == 2:
                 continue
             if opts['only_merges'] and len(parents) != 2:
                 continue
 
             if opts['keyword']:
                 changes = getchange(rev)
                 miss = 0
                 for k in [kw.lower() for kw in opts['keyword']]:
                     if not (k in changes[1].lower() or
                             k in changes[4].lower() or
                             k in " ".join(changes[3][:20]).lower()):
                         miss = 1
                         break
                 if miss:
                     continue
 
             br = None
             if opts['branches']:
                 br = repo.branchlookup([repo.changelog.node(rev)])
 
             displayer.show(rev, brinfo=br)
             if opts['patch']:
                 prev = (parents and parents[0]) or nullid
                 dodiff(du, du, repo, prev, changenode, match=matchfn)
                 du.write("\n\n")
         elif st == 'iter':
             if count == limit: break
             if du.hunk[rev]:
                 count += 1
                 for args in du.hunk[rev]:
                     ui.write(*args)
 
 def manifest(ui, repo, rev=None):
     """output the latest or given revision of the project manifest
 
     Print a list of version controlled files for the given revision.
 
     The manifest is the list of files being version controlled. If no revision
     is given then the tip is used.
     """
     if rev:
         try:
             # assume all revision numbers are for changesets
             n = repo.lookup(rev)
             change = repo.changelog.read(n)
             n = change[0]
         except hg.RepoError:
             n = repo.manifest.lookup(rev)
     else:
         n = repo.manifest.tip()
     m = repo.manifest.read(n)
     mf = repo.manifest.readflags(n)
     files = m.keys()
     files.sort()
 
     for f in files:
         ui.write("%40s %3s %s\n" % (hex(m[f]), mf[f] and "755" or "644", f))
 
 def outgoing(ui, repo, dest="default-push", **opts):
     """show changesets not found in destination
 
     Show changesets not found in the specified destination repository or
     the default push location. These are the changesets that would be pushed
     if a push was requested.
 
     See pull for valid destination format details.
     """
     dest = ui.expandpath(dest)
     if opts['ssh']:
         ui.setconfig("ui", "ssh", opts['ssh'])
     if opts['remotecmd']:
         ui.setconfig("ui", "remotecmd", opts['remotecmd'])
 
     other = hg.repository(ui, dest)
     o = repo.findoutgoing(other, force=opts['force'])
     o = repo.changelog.nodesbetween(o)[0]
     if opts['newest_first']:
         o.reverse()
     displayer = show_changeset(ui, repo, opts)
     for n in o:
         parents = [p for p in repo.changelog.parents(n) if p != nullid]
         if opts['no_merges'] and len(parents) == 2:
             continue
         displayer.show(changenode=n)
         if opts['patch']:
             prev = (parents and parents[0]) or nullid
             dodiff(ui, ui, repo, prev, n)
             ui.write("\n")
 
 def parents(ui, repo, rev=None, branches=None, **opts):
     """show the parents of the working dir or revision
 
     Print the working directory's parent revisions.
     """
     if rev:
         p = repo.changelog.parents(repo.lookup(rev))
     else:
         p = repo.dirstate.parents()
 
     br = None
     if branches is not None:
         br = repo.branchlookup(p)
     displayer = show_changeset(ui, repo, opts)
     for n in p:
         if n != nullid:
             displayer.show(changenode=n, brinfo=br)
 
 def paths(ui, repo, search=None):
     """show definition of symbolic path names
 
     Show definition of symbolic path name NAME. If no name is given, show
     definition of available names.
 
     Path names are defined in the [paths] section of /etc/mercurial/hgrc
     and $HOME/.hgrc.  If run inside a repository, .hg/hgrc is used, too.
     """
     if search:
         for name, path in ui.configitems("paths"):
             if name == search:
                 ui.write("%s\n" % path)
                 return
         ui.warn(_("not found!\n"))
         return 1
     else:
         for name, path in ui.configitems("paths"):
             ui.write("%s = %s\n" % (name, path))
 
 def pull(ui, repo, source="default", **opts):
     """pull changes from the specified source
 
     Pull changes from a remote repository to a local one.
 
     This finds all changes from the repository at the specified path
     or URL and adds them to the local repository. By default, this
     does not update the copy of the project in the working directory.
 
     Valid URLs are of the form:
 
       local/filesystem/path
       http://[user@]host[:port][/path]
       https://[user@]host[:port][/path]
       ssh://[user@]host[:port][/path]
 
     Some notes about using SSH with Mercurial:
     - SSH requires an accessible shell account on the destination machine
       and a copy of hg in the remote path or specified with as remotecmd.
     - /path is relative to the remote user's home directory by default.
       Use two slashes at the start of a path to specify an absolute path.
     - Mercurial doesn't use its own compression via SSH; the right thing
       to do is to configure it in your ~/.ssh/ssh_config, e.g.:
         Host *.mylocalnetwork.example.com
           Compression off
         Host *
           Compression on
       Alternatively specify "ssh -C" as your ssh command in your hgrc or
       with the --ssh command line option.
     """
     source = ui.expandpath(source)
     ui.status(_('pulling from %s\n') % (source))
 
     if opts['ssh']:
         ui.setconfig("ui", "ssh", opts['ssh'])
     if opts['remotecmd']:
         ui.setconfig("ui", "remotecmd", opts['remotecmd'])
 
     other = hg.repository(ui, source)
     revs = None
     if opts['rev'] and not other.local():
         raise util.Abort(_("pull -r doesn't work for remote repositories yet"))
     elif opts['rev']:
         revs = [other.lookup(rev) for rev in opts['rev']]
     r = repo.pull(other, heads=revs, force=opts['force'])
     if not r:
         if opts['update']:
             return update(ui, repo)
         else:
             ui.status(_("(run 'hg update' to get a working copy)\n"))
 
     return r
 
 def push(ui, repo, dest="default-push", **opts):
     """push changes to the specified destination
 
     Push changes from the local repository to the given destination.
 
     This is the symmetrical operation for pull. It helps to move
     changes from the current repository to a different one. If the
     destination is local this is identical to a pull in that directory
     from the current one.
 
     By default, push will refuse to run if it detects the result would
     increase the number of remote heads. This generally indicates the
     the client has forgotten to sync and merge before pushing.
 
     Valid URLs are of the form:
 
       local/filesystem/path
       ssh://[user@]host[:port][/path]
 
     Look at the help text for the pull command for important details
     about ssh:// URLs.
     """
     dest = ui.expandpath(dest)
     ui.status('pushing to %s\n' % (dest))
 
     if opts['ssh']:
         ui.setconfig("ui", "ssh", opts['ssh'])
     if opts['remotecmd']:
         ui.setconfig("ui", "remotecmd", opts['remotecmd'])
 
     other = hg.repository(ui, dest)
     revs = None
     if opts['rev']:
         revs = [repo.lookup(rev) for rev in opts['rev']]
     r = repo.push(other, opts['force'], revs=revs)
     return r
 
 def rawcommit(ui, repo, *flist, **rc):
     """raw commit interface (DEPRECATED)
 
     (DEPRECATED)
     Lowlevel commit, for use in helper scripts.
 
     This command is not intended to be used by normal users, as it is
     primarily useful for importing from other SCMs.
 
     This command is now deprecated and will be removed in a future
     release, please use debugsetparents and commit instead.
     """
 
     ui.warn(_("(the rawcommit command is deprecated)\n"))
 
     message = rc['message']
     if not message and rc['logfile']:
         try:
             message = open(rc['logfile']).read()
         except IOError:
             pass
     if not message and not rc['logfile']:
         raise util.Abort(_("missing commit message"))
 
     files = relpath(repo, list(flist))
     if rc['files']:
         files += open(rc['files']).read().splitlines()
 
     rc['parent'] = map(repo.lookup, rc['parent'])
 
     try:
         repo.rawcommit(files, message, rc['user'], rc['date'], *rc['parent'])
     except ValueError, inst:
         raise util.Abort(str(inst))
 
 def recover(ui, repo):
     """roll back an interrupted transaction
 
     Recover from an interrupted commit or pull.
 
     This command tries to fix the repository status after an interrupted
     operation. It should only be necessary when Mercurial suggests it.
     """
     if repo.recover():
         return repo.verify()
     return False
 
 def remove(ui, repo, pat, *pats, **opts):
     """remove the specified files on the next commit
 
     Schedule the indicated files for removal from the repository.
 
     This command schedules the files to be removed at the next commit.
     This only removes files from the current branch, not from the
     entire project history.  If the files still exist in the working
     directory, they will be deleted from it.
     """
     names = []
     def okaytoremove(abs, rel, exact):
         modified, added, removed, deleted, unknown = repo.changes(files=[abs])
         reason = None
         if modified and not opts['force']:
             reason = _('is modified')
         elif added:
             reason = _('has been marked for add')
         elif unknown:
             reason = _('is not managed')
         if reason:
             if exact:
                 ui.warn(_('not removing %s: file %s\n') % (rel, reason))
         else:
             return True
     for src, abs, rel, exact in walk(repo, (pat,) + pats, opts):
         if okaytoremove(abs, rel, exact):
             if ui.verbose or not exact:
                 ui.status(_('removing %s\n') % rel)
             names.append(abs)
     repo.remove(names, unlink=True)
 
 def rename(ui, repo, *pats, **opts):
     """rename files; equivalent of copy + remove
 
     Mark dest as copies of sources; mark sources for deletion.  If
     dest is a directory, copies are put in that directory.  If dest is
     a file, there can only be one source.
 
     By default, this command copies the contents of files as they
     stand in the working directory.  If invoked with --after, the
     operation is recorded, but no copying is performed.
 
     This command takes effect in the next commit.
 
     NOTE: This command should be treated as experimental. While it
     should properly record rename files, this information is not yet
     fully used by merge, nor fully reported by log.
     """
     try:
         wlock = repo.wlock(0)
         errs, copied = docopy(ui, repo, pats, opts, wlock)
         names = []
         for abs, rel, exact in copied:
             if ui.verbose or not exact:
                 ui.status(_('removing %s\n') % rel)
             names.append(abs)
         repo.remove(names, True, wlock)
     except lock.LockHeld, inst:
         ui.warn(_("repository lock held by %s\n") % inst.args[0])
         errs = 1
     return errs
 
 def revert(ui, repo, *pats, **opts):
     """revert modified files or dirs back to their unmodified states
 
     In its default mode, it reverts any uncommitted modifications made
     to the named files or directories.  This restores the contents of
     the affected files to an unmodified state.
 
     Using the -r option, it reverts the given files or directories to
     their state as of an earlier revision.  This can be helpful to "roll
     back" some or all of a change that should not have been committed.
 
     Revert modifies the working directory.  It does not commit any
     changes, or change the parent of the current working directory.
 
     If a file has been deleted, it is recreated.  If the executable
     mode of a file was changed, it is reset.
 
     If names are given, all files matching the names are reverted.
 
     If no arguments are given, all files in the repository are reverted.
     """
     node = opts['rev'] and repo.lookup(opts['rev']) or \
            repo.dirstate.parents()[0]
 
     files, choose, anypats = matchpats(repo, pats, opts)
     modified, added, removed, deleted, unknown = repo.changes(match=choose)
     repo.forget(added)
     repo.undelete(removed)
 
     return repo.update(node, False, True, choose, False)
 
 def root(ui, repo):
     """print the root (top) of the current working dir
 
     Print the root directory of the current repository.
     """
     ui.write(repo.root + "\n")
 
 def serve(ui, repo, **opts):
     """export the repository via HTTP
 
     Start a local HTTP repository browser and pull server.
 
     By default, the server logs accesses to stdout and errors to
     stderr.  Use the "-A" and "-E" options to log to files.
     """
 
     if opts["stdio"]:
         fin, fout = sys.stdin, sys.stdout
         sys.stdout = sys.stderr
 
         # Prevent insertion/deletion of CRs
         util.set_binary(fin)
         util.set_binary(fout)
 
         def getarg():
             argline = fin.readline()[:-1]
             arg, l = argline.split()
             val = fin.read(int(l))
             return arg, val
         def respond(v):
             fout.write("%d\n" % len(v))
             fout.write(v)
             fout.flush()
 
         lock = None
 
         while 1:
             cmd = fin.readline()[:-1]
             if cmd == '':
                 return
             if cmd == "heads":
                 h = repo.heads()
                 respond(" ".join(map(hex, h)) + "\n")
             if cmd == "lock":
                 lock = repo.lock()
                 respond("")
             if cmd == "unlock":
                 if lock:
                     lock.release()
                 lock = None
                 respond("")
             elif cmd == "branches":
                 arg, nodes = getarg()
                 nodes = map(bin, nodes.split(" "))
                 r = []
                 for b in repo.branches(nodes):
                     r.append(" ".join(map(hex, b)) + "\n")
                 respond("".join(r))
             elif cmd == "between":
                 arg, pairs = getarg()
                 pairs = [map(bin, p.split("-")) for p in pairs.split(" ")]
                 r = []
                 for b in repo.between(pairs):
                     r.append(" ".join(map(hex, b)) + "\n")
                 respond("".join(r))
             elif cmd == "changegroup":
                 nodes = []
                 arg, roots = getarg()
                 nodes = map(bin, roots.split(" "))
 
                 cg = repo.changegroup(nodes, 'serve')
                 while 1:
                     d = cg.read(4096)
                     if not d:
                         break
                     fout.write(d)
 
                 fout.flush()
 
             elif cmd == "addchangegroup":
                 if not lock:
                     respond("not locked")
                     continue
                 respond("")
 
                 r = repo.addchangegroup(fin)
                 respond("")
 
     optlist = "name templates style address port ipv6 accesslog errorlog"
     for o in optlist.split():
         if opts[o]:
             ui.setconfig("web", o, opts[o])
 
     if opts['daemon'] and not opts['daemon_pipefds']:
         rfd, wfd = os.pipe()
         args = sys.argv[:]
         args.append('--daemon-pipefds=%d,%d' % (rfd, wfd))
         pid = os.spawnvp(os.P_NOWAIT | getattr(os, 'P_DETACH', 0),
                          args[0], args)
         os.close(wfd)
         os.read(rfd, 1)
         os._exit(0)
 
     try:
         httpd = hgweb.create_server(repo)
     except socket.error, inst:
         raise util.Abort(_('cannot start server: ') + inst.args[1])
 
     if ui.verbose:
         addr, port = httpd.socket.getsockname()
         if addr == '0.0.0.0':
             addr = socket.gethostname()
         else:
             try:
                 addr = socket.gethostbyaddr(addr)[0]
             except socket.error:
                 pass
         if port != 80:
             ui.status(_('listening at http://%s:%d/\n') % (addr, port))
         else:
             ui.status(_('listening at http://%s/\n') % addr)
 
     if opts['pid_file']:
         fp = open(opts['pid_file'], 'w')
         fp.write(str(os.getpid()))
         fp.close()
 
     if opts['daemon_pipefds']:
         rfd, wfd = [int(x) for x in opts['daemon_pipefds'].split(',')]
         os.close(rfd)
         os.write(wfd, 'y')
         os.close(wfd)
         sys.stdout.flush()
         sys.stderr.flush()
         fd = os.open(util.nulldev, os.O_RDWR)
         if fd != 0: os.dup2(fd, 0)
         if fd != 1: os.dup2(fd, 1)
         if fd != 2: os.dup2(fd, 2)
         if fd not in (0, 1, 2): os.close(fd)
 
     httpd.serve_forever()
 
 def status(ui, repo, *pats, **opts):
     """show changed files in the working directory
 
     Show changed files in the repository.  If names are
     given, only files that match are shown.
 
     The codes used to show the status of files are:
     M = modified
     A = added
     R = removed
     ! = deleted, but still tracked
     ? = not tracked
     """
 
     files, matchfn, anypats = matchpats(repo, pats, opts)
     cwd = (pats and repo.getcwd()) or ''
     modified, added, removed, deleted, unknown = [
         [util.pathto(cwd, x) for x in n]
         for n in repo.changes(files=files, match=matchfn)]
 
     changetypes = [('modified', 'M', modified),
                    ('added', 'A', added),
                    ('removed', 'R', removed),
                    ('deleted', '!', deleted),
                    ('unknown', '?', unknown)]
 
     end = opts['print0'] and '\0' or '\n'
 
     for opt, char, changes in ([ct for ct in changetypes if opts[ct[0]]]
                                or changetypes):
         if opts['no_status']:
             format = "%%s%s" % end
         else:
             format = "%s %%s%s" % (char, end)
 
         for f in changes:
             ui.write(format % f)
 
 def tag(ui, repo, name, rev_=None, **opts):
     """add a tag for the current tip or a given revision
 
     Name a particular revision using <name>.
 
     Tags are used to name particular revisions of the repository and are
     very useful to compare different revision, to go back to significant
     earlier versions or to mark branch points as releases, etc.
 
     If no revision is given, the tip is used.
 
     To facilitate version control, distribution, and merging of tags,
     they are stored as a file named ".hgtags" which is managed
     similarly to other project files and can be hand-edited if
     necessary.  The file '.hg/localtags' is used for local tags (not
     shared among repositories).
     """
     if name == "tip":
         raise util.Abort(_("the name 'tip' is reserved"))
     if rev_ is not None:
         ui.warn(_("use of 'hg tag NAME [REV]' is deprecated, "
                   "please use 'hg tag [-r REV] NAME' instead\n"))
         if opts['rev']:
             raise util.Abort(_("use only one form to specify the revision"))
     if opts['rev']:
         rev_ = opts['rev']
     if rev_:
         r = hex(repo.lookup(rev_))
     else:
         r = hex(repo.changelog.tip())
 
     disallowed = (revrangesep, '\r', '\n')
     for c in disallowed:
         if name.find(c) >= 0:
             raise util.Abort(_("%s cannot be used in a tag name") % repr(c))
 
     repo.hook('pretag', throw=True, node=r, tag=name,
               local=int(not not opts['local']))
 
     if opts['local']:
         repo.opener("localtags", "a").write("%s %s\n" % (r, name))
         repo.hook('tag', node=r, tag=name, local=1)
         return
 
     for x in repo.changes():
         if ".hgtags" in x:
             raise util.Abort(_("working copy of .hgtags is changed "
                                "(please commit .hgtags manually)"))
 
     repo.wfile(".hgtags", "ab").write("%s %s\n" % (r, name))
     if repo.dirstate.state(".hgtags") == '?':
         repo.add([".hgtags"])
 
     message = (opts['message'] or
                _("Added tag %s for changeset %s") % (name, r))
     try:
         repo.commit([".hgtags"], message, opts['user'], opts['date'])
         repo.hook('tag', node=r, tag=name, local=0)
     except ValueError, inst:
         raise util.Abort(str(inst))
 
 def tags(ui, repo):
     """list repository tags
 
     List the repository tags.
 
     This lists both regular and local tags.
     """
 
     l = repo.tagslist()
     l.reverse()
     for t, n in l:
         try:
             r = "%5d:%s" % (repo.changelog.rev(n), hex(n))
         except KeyError:
             r = "    ?:?"
         ui.write("%-30s %s\n" % (t, r))
 
 def tip(ui, repo, **opts):
     """show the tip revision
 
     Show the tip revision.
     """
     n = repo.changelog.tip()
     br = None
     if opts['branches']:
         br = repo.branchlookup([n])
     show_changeset(ui, repo, opts).show(changenode=n, brinfo=br)
     if opts['patch']:
         dodiff(ui, ui, repo, repo.changelog.parents(n)[0], n)
 
 def unbundle(ui, repo, fname, **opts):
     """apply a changegroup file
 
     Apply a compressed changegroup file generated by the bundle
     command.
     """
     f = urllib.urlopen(fname)
 
     header = f.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)
     elif header == "HG10BZ":
         def generator(f):
             zd = bz2.BZ2Decompressor()
             zd.decompress("BZ")
             for chunk in f:
                 yield zd.decompress(chunk)
     elif header == "HG10UN":
         def generator(f):
             for chunk in f:
                 yield chunk
     else:
         raise util.Abort(_("%s: unknown bundle compression type")
                          % fname)
     gen = generator(util.filechunkiter(f, 4096))
     if repo.addchangegroup(util.chunkbuffer(gen)):
         return 1
 
     if opts['update']:
         return update(ui, repo)
     else:
         ui.status(_("(run 'hg update' to get a working copy)\n"))
 
 def undo(ui, repo):
     """undo the last commit or pull
 
     Roll back the last pull or commit transaction on the
     repository, restoring the project to its earlier state.
 
     This command should be used with care. There is only one level of
     undo and there is no redo.
 
     This command is not intended for use on public repositories. Once
     a change is visible for pull by other users, undoing it locally is
     ineffective.
     """
     repo.undo()
 
 def update(ui, repo, node=None, merge=False, clean=False, force=None,
            branch=None, **opts):
     """update or merge working directory
 
     Update the working directory to the specified revision.
 
     If there are no outstanding changes in the working directory and
     there is a linear relationship between the current version and the
     requested version, the result is the requested version.
 
     Otherwise the result is a merge between the contents of the
     current working directory and the requested version. Files that
     changed between either parent are marked as changed for the next
     commit and a commit must be performed before any further updates
     are allowed.
 
     By default, update will refuse to run if doing so would require
     merging or discarding local changes.
     """
     if branch:
         br = repo.branchlookup(branch=branch)
         found = []
         for x in br:
             if branch in br[x]:
                 found.append(x)
         if len(found) > 1:
             ui.warn(_("Found multiple heads for %s\n") % branch)
             for x in found:
                 show_changeset(ui, repo, opts).show(changenode=x, brinfo=br)
             return 1
         if len(found) == 1:
             node = found[0]
             ui.warn(_("Using head %s for branch %s\n") % (short(node), branch))
         else:
             ui.warn(_("branch %s not found\n") % (branch))
             return 1
     else:
         node = node and repo.lookup(node) or repo.changelog.tip()
     return repo.update(node, allow=merge, force=clean, forcemerge=force)
 
 def verify(ui, repo):
     """verify the integrity of the repository
 
     Verify the integrity of the current repository.
 
     This will perform an extensive check of the repository's
     integrity, validating the hashes and checksums of each entry in
     the changelog, manifest, and tracked files, as well as the
     integrity of their crosslinks and indices.
     """
     return repo.verify()
 
 # Command options and aliases are listed here, alphabetically
 
 table = {
     "^add":
         (add,
          [('I', 'include', [], _('include names matching the given patterns')),
           ('X', 'exclude', [], _('exclude names matching the given patterns'))],
          _('hg add [OPTION]... [FILE]...')),
     "addremove":
         (addremove,
          [('I', 'include', [], _('include names matching the given patterns')),
           ('X', 'exclude', [], _('exclude names matching the given patterns'))],
          _('hg addremove [OPTION]... [FILE]...')),
     "^annotate":
         (annotate,
          [('r', 'rev', '', _('annotate the specified revision')),
           ('a', 'text', None, _('treat all files as text')),
           ('u', 'user', None, _('list the author')),
           ('d', 'date', None, _('list the date')),
           ('n', 'number', None, _('list the revision number (default)')),
           ('c', 'changeset', None, _('list the changeset')),
           ('I', 'include', [], _('include names matching the given patterns')),
           ('X', 'exclude', [], _('exclude names matching the given patterns'))],
          _('hg annotate [-r REV] [-a] [-u] [-d] [-n] [-c] FILE...')),
     "bundle":
         (bundle,
          [('f', 'force', None,
            _('run even when remote repository is unrelated'))],
          _('hg bundle FILE DEST')),
     "cat":
         (cat,
          [('o', 'output', '', _('print output to file with formatted name')),
           ('r', 'rev', '', _('print the given revision')),
           ('I', 'include', [], _('include names matching the given patterns')),
           ('X', 'exclude', [], _('exclude names matching the given patterns'))],
          _('hg cat [OPTION]... FILE...')),
     "^clone":
         (clone,
          [('U', 'noupdate', None, _('do not update the new working directory')),
           ('r', 'rev', [],
            _('a changeset you would like to have after cloning')),
           ('', 'pull', None, _('use pull protocol to copy metadata')),
           ('e', 'ssh', '', _('specify ssh command to use')),
           ('', 'remotecmd', '',
            _('specify hg command to run on the remote side'))],
          _('hg clone [OPTION]... SOURCE [DEST]')),
     "^commit|ci":
         (commit,
          [('A', 'addremove', None, _('run addremove during commit')),
           ('m', 'message', '', _('use <text> as commit message')),
           ('l', 'logfile', '', _('read the commit message from <file>')),
           ('d', 'date', '', _('record datecode as commit date')),
           ('u', 'user', '', _('record user as commiter')),
           ('I', 'include', [], _('include names matching the given patterns')),
           ('X', 'exclude', [], _('exclude names matching the given patterns'))],
          _('hg commit [OPTION]... [FILE]...')),
     "copy|cp":
         (copy,
          [('A', 'after', None, _('record a copy that has already occurred')),
           ('f', 'force', None,
            _('forcibly copy over an existing managed file')),
           ('I', 'include', [], _('include names matching the given patterns')),
           ('X', 'exclude', [], _('exclude names matching the given patterns'))],
          _('hg copy [OPTION]... [SOURCE]... DEST')),
     "debugancestor": (debugancestor, [], _('debugancestor INDEX REV1 REV2')),
     "debugcomplete": (debugcomplete, [], _('debugcomplete CMD')),
     "debugrebuildstate":
         (debugrebuildstate,
          [('r', 'rev', '', _('revision to rebuild to'))],
          _('debugrebuildstate [-r REV] [REV]')),
     "debugcheckstate": (debugcheckstate, [], _('debugcheckstate')),
     "debugconfig": (debugconfig, [], _('debugconfig')),
     "debugsetparents": (debugsetparents, [], _('debugsetparents REV1 [REV2]')),
     "debugstate": (debugstate, [], _('debugstate')),
     "debugdata": (debugdata, [], _('debugdata FILE REV')),
     "debugindex": (debugindex, [], _('debugindex FILE')),
     "debugindexdot": (debugindexdot, [], _('debugindexdot FILE')),
     "debugrename": (debugrename, [], _('debugrename FILE [REV]')),
     "debugwalk":
         (debugwalk,
          [('I', 'include', [], _('include names matching the given patterns')),
           ('X', 'exclude', [], _('exclude names matching the given patterns'))],
          _('debugwalk [OPTION]... [FILE]...')),
     "^diff":
         (diff,
          [('r', 'rev', [], _('revision')),
           ('a', 'text', None, _('treat all files as text')),
           ('p', 'show-function', None,
            _('show which function each change is in')),
           ('w', 'ignore-all-space', None,
            _('ignore white space when comparing lines')),
           ('I', 'include', [], _('include names matching the given patterns')),
           ('X', 'exclude', [], _('exclude names matching the given patterns'))],
          _('hg diff [-a] [-I] [-X] [-r REV1 [-r REV2]] [FILE]...')),
     "^export":
         (export,
          [('o', 'output', '', _('print output to file with formatted name')),
           ('a', 'text', None, _('treat all files as text')),
           ('', 'switch-parent', None, _('diff against the second parent'))],
          _('hg export [-a] [-o OUTFILESPEC] REV...')),
     "forget":
         (forget,
          [('I', 'include', [], _('include names matching the given patterns')),
           ('X', 'exclude', [], _('exclude names matching the given patterns'))],
          _('hg forget [OPTION]... FILE...')),
     "grep":
         (grep,
          [('0', 'print0', None, _('end fields with NUL')),
           ('', 'all', None, _('print all revisions that match')),
           ('i', 'ignore-case', None, _('ignore case when matching')),
           ('l', 'files-with-matches', None,
            _('print only filenames and revs that match')),
           ('n', 'line-number', None, _('print matching line numbers')),
           ('r', 'rev', [], _('search in given revision range')),
           ('u', 'user', None, _('print user who committed change')),
           ('I', 'include', [], _('include names matching the given patterns')),
           ('X', 'exclude', [], _('exclude names matching the given patterns'))],
          _('hg grep [OPTION]... PATTERN [FILE]...')),
     "heads":
         (heads,
          [('b', 'branches', None, _('show branches')),
           ('', 'style', '', _('display using template map file')),
           ('r', 'rev', '', _('show only heads which are descendants of rev')),
           ('', 'template', '', _('display with template'))],
          _('hg heads [-b] [-r <rev>]')),
     "help": (help_, [], _('hg help [COMMAND]')),
     "identify|id": (identify, [], _('hg identify')),
     "import|patch":
         (import_,
          [('p', 'strip', 1,
            _('directory strip option for patch. This has the same\n') +
            _('meaning as the corresponding patch option')),
           ('b', 'base', '', _('base path')),
           ('f', 'force', None,
            _('skip check for outstanding uncommitted changes'))],
          _('hg import [-p NUM] [-b BASE] [-f] PATCH...')),
     "incoming|in": (incoming,
          [('M', 'no-merges', None, _('do not show merges')),
           ('f', 'force', None,
            _('run even when remote repository is unrelated')),
           ('', 'style', '', _('display using template map file')),
           ('n', 'newest-first', None, _('show newest record first')),
           ('', 'bundle', '', _('file to store the bundles into')),
           ('p', 'patch', None, _('show patch')),
           ('', 'template', '', _('display with template')),
           ('e', 'ssh', '', _('specify ssh command to use')),
           ('', 'remotecmd', '',
            _('specify hg command to run on the remote side'))],
          _('hg incoming [-p] [-n] [-M] [--bundle FILENAME] [SOURCE]')),
     "^init": (init, [], _('hg init [DEST]')),
     "locate":
         (locate,
          [('r', 'rev', '', _('search the repository as it stood at rev')),
           ('0', 'print0', None,
            _('end filenames with NUL, for use with xargs')),
           ('f', 'fullpath', None,
            _('print complete paths from the filesystem root')),
           ('I', 'include', [], _('include names matching the given patterns')),
           ('X', 'exclude', [], _('exclude names matching the given patterns'))],
          _('hg locate [OPTION]... [PATTERN]...')),
     "^log|history":
         (log,
          [('b', 'branches', None, _('show branches')),
           ('k', 'keyword', [], _('search for a keyword')),
           ('l', 'limit', '', _('limit number of changes displayed')),
           ('r', 'rev', [], _('show the specified revision or range')),
           ('M', 'no-merges', None, _('do not show merges')),
           ('', 'style', '', _('display using template map file')),
           ('m', 'only-merges', None, _('show only merges')),
           ('p', 'patch', None, _('show patch')),
           ('', 'template', '', _('display with template')),
           ('I', 'include', [], _('include names matching the given patterns')),
           ('X', 'exclude', [], _('exclude names matching the given patterns'))],
          _('hg log [OPTION]... [FILE]')),
     "manifest": (manifest, [], _('hg manifest [REV]')),
     "outgoing|out": (outgoing,
          [('M', 'no-merges', None, _('do not show merges')),
           ('f', 'force', None,
            _('run even when remote repository is unrelated')),
           ('p', 'patch', None, _('show patch')),
           ('', 'style', '', _('display using template map file')),
           ('n', 'newest-first', None, _('show newest record first')),
           ('', 'template', '', _('display with template')),
           ('e', 'ssh', '', _('specify ssh command to use')),
           ('', 'remotecmd', '',
            _('specify hg command to run on the remote side'))],
          _('hg outgoing [-M] [-p] [-n] [DEST]')),
     "^parents":
         (parents,
          [('b', 'branches', None, _('show branches')),
           ('', 'style', '', _('display using template map file')),
           ('', 'template', '', _('display with template'))],
          _('hg parents [-b] [REV]')),
     "paths": (paths, [], _('hg paths [NAME]')),
     "^pull":
         (pull,
          [('u', 'update', None,
            _('update the working directory to tip after pull')),
           ('e', 'ssh', '', _('specify ssh command to use')),
           ('f', 'force', None,
            _('run even when remote repository is unrelated')),
           ('r', 'rev', [], _('a specific revision you would like to pull')),
           ('', 'remotecmd', '',
            _('specify hg command to run on the remote side'))],
          _('hg pull [-u] [-e FILE] [-r REV]... [--remotecmd FILE] [SOURCE]')),
     "^push":
         (push,
          [('f', 'force', None, _('force push')),
           ('e', 'ssh', '', _('specify ssh command to use')),
           ('r', 'rev', [], _('a specific revision you would like to push')),
           ('', 'remotecmd', '',
            _('specify hg command to run on the remote side'))],
          _('hg push [-f] [-e FILE] [-r REV]... [--remotecmd FILE] [DEST]')),
     "debugrawcommit|rawcommit":
         (rawcommit,
          [('p', 'parent', [], _('parent')),
           ('d', 'date', '', _('date code')),
           ('u', 'user', '', _('user')),
           ('F', 'files', '', _('file list')),
           ('m', 'message', '', _('commit message')),
           ('l', 'logfile', '', _('commit message file'))],
          _('hg debugrawcommit [OPTION]... [FILE]...')),
     "recover": (recover, [], _('hg recover')),
     "^remove|rm":
         (remove,
          [('f', 'force', None, _('remove file even if modified')),
           ('I', 'include', [], _('include names matching the given patterns')),
           ('X', 'exclude', [], _('exclude names matching the given patterns'))],
          _('hg remove [OPTION]... FILE...')),
     "rename|mv":
         (rename,
          [('A', 'after', None, _('record a rename that has already occurred')),
           ('f', 'force', None,
            _('forcibly copy over an existing managed file')),
           ('I', 'include', [], _('include names matching the given patterns')),
           ('X', 'exclude', [], _('exclude names matching the given patterns'))],
          _('hg rename [OPTION]... SOURCE... DEST')),
     "^revert":
         (revert,
          [('r', 'rev', '', _('revision to revert to')),
           ('I', 'include', [], _('include names matching the given patterns')),
           ('X', 'exclude', [], _('exclude names matching the given patterns'))],
          _('hg revert [-r REV] [NAME]...')),
     "root": (root, [], _('hg root')),
     "^serve":
         (serve,
          [('A', 'accesslog', '', _('name of access log file to write to')),
           ('d', 'daemon', None, _('run server in background')),
           ('', 'daemon-pipefds', '', _('used internally by daemon mode')),
           ('E', 'errorlog', '', _('name of error log file to write to')),
           ('p', 'port', 0, _('port to use (default: 8000)')),
           ('a', 'address', '', _('address to use')),
           ('n', 'name', '',
            _('name to show in web pages (default: working dir)')),
           ('', 'pid-file', '', _('name of file to write process ID to')),
           ('', 'stdio', None, _('for remote clients')),
           ('t', 'templates', '', _('web templates to use')),
           ('', 'style', '', _('template style to use')),
           ('6', 'ipv6', None, _('use IPv6 in addition to IPv4'))],
          _('hg serve [OPTION]...')),
     "^status|st":
         (status,
          [('m', 'modified', None, _('show only modified files')),
           ('a', 'added', None, _('show only added files')),
           ('r', 'removed', None, _('show only removed files')),
           ('d', 'deleted', None, _('show only deleted (but tracked) files')),
           ('u', 'unknown', None, _('show only unknown (not tracked) files')),
           ('n', 'no-status', None, _('hide status prefix')),
           ('0', 'print0', None,
            _('end filenames with NUL, for use with xargs')),
           ('I', 'include', [], _('include names matching the given patterns')),
           ('X', 'exclude', [], _('exclude names matching the given patterns'))],
          _('hg status [OPTION]... [FILE]...')),
     "tag":
         (tag,
          [('l', 'local', None, _('make the tag local')),
           ('m', 'message', '', _('message for tag commit log entry')),
           ('d', 'date', '', _('record datecode as commit date')),
           ('u', 'user', '', _('record user as commiter')),
           ('r', 'rev', '', _('revision to tag'))],
          _('hg tag [-l] [-m TEXT] [-d DATE] [-u USER] [-r REV] NAME')),
     "tags": (tags, [], _('hg tags')),
     "tip":
         (tip,
          [('b', 'branches', None, _('show branches')),
           ('', 'style', '', _('display using template map file')),
           ('p', 'patch', None, _('show patch')),
           ('', 'template', '', _('display with template'))],
          _('hg tip [-b] [-p]')),
     "unbundle":
         (unbundle,
          [('u', 'update', None,
            _('update the working directory to tip after unbundle'))],
          _('hg unbundle [-u] FILE')),
     "undo": (undo, [], _('hg undo')),
     "^update|up|checkout|co":
         (update,
          [('b', 'branch', '', _('checkout the head of a specific branch')),
           ('', 'style', '', _('display using template map file')),
           ('m', 'merge', None, _('allow merging of branches')),
           ('C', 'clean', None, _('overwrite locally modified files')),
           ('f', 'force', None, _('force a merge with outstanding changes')),
           ('', 'template', '', _('display with template'))],
          _('hg update [-b TAG] [-m] [-C] [-f] [REV]')),
     "verify": (verify, [], _('hg verify')),
     "version": (show_version, [], _('hg version')),
 }
 
 globalopts = [
     ('R', 'repository', '',
      _('repository root directory or symbolic path name')),
     ('', 'cwd', '', _('change working directory')),
     ('y', 'noninteractive', None,
      _('do not prompt, assume \'yes\' for any required answers')),
     ('q', 'quiet', None, _('suppress output')),
     ('v', 'verbose', None, _('enable additional output')),
     ('', 'debug', None, _('enable debugging output')),
     ('', 'debugger', None, _('start debugger')),
     ('', 'traceback', None, _('print traceback on exception')),
     ('', 'time', None, _('time how long the command takes')),
     ('', 'profile', None, _('print command execution profile')),
     ('', 'version', None, _('output version information and exit')),
     ('h', 'help', None, _('display help and exit')),
 ]
 
 norepo = ("clone init version help debugancestor debugcomplete debugdata"
           " debugindex debugindexdot")
 optionalrepo = ("paths debugconfig")
 
 def findpossible(cmd):
     """
     Return cmd -> (aliases, command table entry)
     for each matching command
     """
     choice = {}
     debugchoice = {}
     for e in table.keys():
         aliases = e.lstrip("^").split("|")
         if cmd in aliases:
             choice[cmd] = (aliases, table[e])
             continue
         for a in aliases:
             if a.startswith(cmd):
                 if aliases[0].startswith("debug"):
                     debugchoice[a] = (aliases, table[e])
                 else:
                     choice[a] = (aliases, table[e])
                 break
 
     if not choice and debugchoice:
         choice = debugchoice
 
     return choice
 
 def find(cmd):
     """Return (aliases, command table entry) for command string."""
     choice = findpossible(cmd)
 
     if choice.has_key(cmd):
         return choice[cmd]
 
     if len(choice) > 1:
         clist = choice.keys()
         clist.sort()
         raise AmbiguousCommand(cmd, clist)
 
     if choice:
         return choice.values()[0]
 
     raise UnknownCommand(cmd)
 
 class SignalInterrupt(Exception):
     """Exception raised on SIGTERM and SIGHUP."""
 
 def catchterm(*args):
     raise SignalInterrupt
 
 def run():
     sys.exit(dispatch(sys.argv[1:]))
 
 class ParseError(Exception):
     """Exception raised on errors in parsing the command line."""
 
 def parse(ui, args):
     options = {}
     cmdoptions = {}
 
     try:
         args = fancyopts.fancyopts(args, globalopts, options)
     except fancyopts.getopt.GetoptError, inst:
         raise ParseError(None, inst)
 
     if args:
         cmd, args = args[0], args[1:]
         aliases, i = find(cmd)
         cmd = aliases[0]
         defaults = ui.config("defaults", cmd)
         if defaults:
             args = defaults.split() + args
         c = list(i[1])
     else:
         cmd = None
         c = []
 
     # combine global options into local
     for o in globalopts:
         c.append((o[0], o[1], options[o[1]], o[3]))
 
     try:
         args = fancyopts.fancyopts(args, c, cmdoptions)
     except fancyopts.getopt.GetoptError, inst:
         raise ParseError(cmd, inst)
 
     # separate global options back out
     for o in globalopts:
         n = o[1]
         options[n] = cmdoptions[n]
         del cmdoptions[n]
 
     return (cmd, cmd and i[0] or None, args, options, cmdoptions)
 
 def dispatch(args):
     signal.signal(signal.SIGTERM, catchterm)
     try:
         signal.signal(signal.SIGHUP, catchterm)
     except AttributeError:
         pass
 
     try:
         u = ui.ui()
     except util.Abort, inst:
         sys.stderr.write(_("abort: %s\n") % inst)
         sys.exit(1)
 
     external = []
     for x in u.extensions():
         def on_exception(exc, inst):
             u.warn(_("*** failed to import extension %s\n") % x[1])
             u.warn("%s\n" % inst)
             if "--traceback" in sys.argv[1:]:
                 traceback.print_exc()
         if x[1]:
             try:
                 mod = imp.load_source(x[0], x[1])
             except Exception, inst:
                 on_exception(Exception, inst)
                 continue
         else:
             def importh(name):
                 mod = __import__(name)
                 components = name.split('.')
                 for comp in components[1:]:
                     mod = getattr(mod, comp)
                 return mod
             try:
                 try:
                     mod = importh("hgext." + x[0])
                 except ImportError:
                     mod = importh(x[0])
             except Exception, inst:
                 on_exception(Exception, inst)
                 continue
 
         external.append(mod)
     for x in external:
         cmdtable = getattr(x, 'cmdtable', {})
         for t in cmdtable:
             if t in table:
                 u.warn(_("module %s overrides %s\n") % (x.__name__, t))
         table.update(cmdtable)
 
     try:
         cmd, func, args, options, cmdoptions = parse(u, args)
         if options["time"]:
             def get_times():
                 t = os.times()
                 if t[4] == 0.0: # Windows leaves this as zero, so use time.clock()
                     t = (t[0], t[1], t[2], t[3], time.clock())
                 return t
             s = get_times()
             def print_time():
                 t = get_times()
                 u.warn(_("Time: real %.3f secs (user %.3f+%.3f sys %.3f+%.3f)\n") %
                     (t[4]-s[4], t[0]-s[0], t[2]-s[2], t[1]-s[1], t[3]-s[3]))
             atexit.register(print_time)
 
         u.updateopts(options["verbose"], options["debug"], options["quiet"],
                 not options["noninteractive"])
 
         # enter the debugger before command execution
         if options['debugger']:
             pdb.set_trace()
 
         try:
             if options['cwd']:
                 try:
                     os.chdir(options['cwd'])
                 except OSError, inst:
                     raise util.Abort('%s: %s' %
                                      (options['cwd'], inst.strerror))
 
             path = u.expandpath(options["repository"]) or ""
             repo = path and hg.repository(u, path=path) or None
 
             if options['help']:
                 help_(u, cmd, options['version'])
                 sys.exit(0)
             elif options['version']:
                 show_version(u)
                 sys.exit(0)
             elif not cmd:
                 help_(u, 'shortlist')
                 sys.exit(0)
 
             if cmd not in norepo.split():
                 try:
                     if not repo:
                         repo = hg.repository(u, path=path)
                     u = repo.ui
                     for x in external:
                         if hasattr(x, 'reposetup'):
                             x.reposetup(u, repo)
                 except hg.RepoError:
                     if cmd not in optionalrepo.split():
                         raise
                 d = lambda: func(u, repo, *args, **cmdoptions)
             else:
                 d = lambda: func(u, *args, **cmdoptions)
 
             try:
                 if options['profile']:
                     import hotshot, hotshot.stats
                     prof = hotshot.Profile("hg.prof")
                     try:
                         try:
                             return prof.runcall(d)
                         except:
                             try:
                                 u.warn(_('exception raised - generating '
                                          'profile anyway\n'))
                             except:
                                 pass
                             raise
                     finally:
                         prof.close()
                         stats = hotshot.stats.load("hg.prof")
                         stats.strip_dirs()
                         stats.sort_stats('time', 'calls')
                         stats.print_stats(40)
                 else:
                     return d()
             finally:
                 u.flush()
         except:
             # enter the debugger when we hit an exception
             if options['debugger']:
                 pdb.post_mortem(sys.exc_info()[2])
             if options['traceback']:
                 traceback.print_exc()
             raise
     except ParseError, inst:
         if inst.args[0]:
             u.warn(_("hg %s: %s\n") % (inst.args[0], inst.args[1]))
             help_(u, inst.args[0])
         else:
             u.warn(_("hg: %s\n") % inst.args[1])
             help_(u, 'shortlist')
         sys.exit(-1)
     except AmbiguousCommand, inst:
         u.warn(_("hg: command '%s' is ambiguous:\n    %s\n") %
                 (inst.args[0], " ".join(inst.args[1])))
         sys.exit(1)
     except UnknownCommand, inst:
         u.warn(_("hg: unknown command '%s'\n") % inst.args[0])
         help_(u, 'shortlist')
         sys.exit(1)
     except hg.RepoError, inst:
         u.warn(_("abort: "), inst, "!\n")
     except revlog.RevlogError, inst:
         u.warn(_("abort: "), inst, "!\n")
     except SignalInterrupt:
         u.warn(_("killed!\n"))
     except KeyboardInterrupt:
         try:
             u.warn(_("interrupted!\n"))
         except IOError, inst:
             if inst.errno == errno.EPIPE:
                 if u.debugflag:
                     u.warn(_("\nbroken pipe\n"))
             else:
                 raise
     except IOError, inst:
         if hasattr(inst, "code"):
             u.warn(_("abort: %s\n") % inst)
         elif hasattr(inst, "reason"):
             u.warn(_("abort: error: %s\n") % inst.reason[1])
         elif hasattr(inst, "args") and inst[0] == errno.EPIPE:
             if u.debugflag:
                 u.warn(_("broken pipe\n"))
         elif getattr(inst, "strerror", None):
             if getattr(inst, "filename", None):
                 u.warn(_("abort: %s - %s\n") % (inst.strerror, inst.filename))
             else:
                 u.warn(_("abort: %s\n") % inst.strerror)
         else:
             raise
     except OSError, inst:
         if hasattr(inst, "filename"):
             u.warn(_("abort: %s: %s\n") % (inst.strerror, inst.filename))
         else:
             u.warn(_("abort: %s\n") % inst.strerror)
     except util.Abort, inst:
         u.warn(_('abort: '), inst.args[0] % inst.args[1:], '\n')
         sys.exit(1)
     except TypeError, inst:
         # was this an argument error?
         tb = traceback.extract_tb(sys.exc_info()[2])
         if len(tb) > 2: # no
             raise
         u.debug(inst, "\n")
         u.warn(_("%s: invalid arguments\n") % cmd)
         help_(u, cmd)
     except SystemExit:
         # don't catch this in the catch-all below
         raise
     except:
         u.warn(_("** unknown exception encountered, details follow\n"))
         u.warn(_("** report bug details to [e-mail]\n"))
         u.warn(_("** Mercurial Distributed SCM (version %s)\n")
                % version.get_version())
         raise
 
     sys.exit(-1)

mercurial/localrepo.py

@@ -1,1911 +1,1894 b''
 # localrepo.py - read/write repository class for mercurial
 #
 # Copyright 2005 Matt Mackall <[e-mail]>
 #
 # This software may be used and distributed according to the terms
 # of the GNU General Public License, incorporated herein by reference.
 
-import struct, os, util
+import os, util
 import filelog, manifest, changelog, dirstate, repo
 from node import *
 from i18n import gettext as _
 from demandload import *
 demandload(globals(), "re lock transaction tempfile stat mdiff errno ui")
+demandload(globals(), "changegroup")
 
 class localrepository(object):
     def __del__(self):
         self.transhandle = None
     def __init__(self, parentui, path=None, create=0):
         if not path:
             p = os.getcwd()
             while not os.path.isdir(os.path.join(p, ".hg")):
                 oldp = p
                 p = os.path.dirname(p)
                 if p == oldp:
                     raise repo.RepoError(_("no repo found"))
             path = p
         self.path = os.path.join(path, ".hg")
 
         if not create and not os.path.isdir(self.path):
             raise repo.RepoError(_("repository %s not found") % path)
 
         self.root = os.path.abspath(path)
         self.ui = ui.ui(parentui=parentui)
         self.opener = util.opener(self.path)
         self.wopener = util.opener(self.root)
         self.manifest = manifest.manifest(self.opener)
         self.changelog = changelog.changelog(self.opener)
         self.tagscache = None
         self.nodetagscache = None
         self.encodepats = None
         self.decodepats = None
         self.transhandle = None
 
         if create:
             os.mkdir(self.path)
             os.mkdir(self.join("data"))
 
         self.dirstate = dirstate.dirstate(self.opener, self.ui, self.root)
         try:
             self.ui.readconfig(self.join("hgrc"), self.root)
         except IOError:
             pass
 
     def hook(self, name, throw=False, **args):
         def runhook(name, cmd):
             self.ui.note(_("running hook %s: %s\n") % (name, cmd))
             env = dict([('HG_' + k.upper(), v) for k, v in args.iteritems()] +
                        [(k.upper(), v) for k, v in args.iteritems()])
             r = util.system(cmd, environ=env, cwd=self.root)
             if r:
                 desc, r = util.explain_exit(r)
                 if throw:
                     raise util.Abort(_('%s hook %s') % (name, desc))
                 self.ui.warn(_('error: %s hook %s\n') % (name, desc))
                 return False
             return True
 
         r = True
         hooks = [(hname, cmd) for hname, cmd in self.ui.configitems("hooks")
                  if hname.split(".", 1)[0] == name and cmd]
         hooks.sort()
         for hname, cmd in hooks:
             r = runhook(hname, cmd) and r
         return r
 
     def tags(self):
         '''return a mapping of tag to node'''
         if not self.tagscache:
             self.tagscache = {}
             def addtag(self, k, n):
                 try:
                     bin_n = bin(n)
                 except TypeError:
                     bin_n = ''
                 self.tagscache[k.strip()] = bin_n
 
             try:
                 # read each head of the tags file, ending with the tip
                 # and add each tag found to the map, with "newer" ones
                 # taking precedence
                 fl = self.file(".hgtags")
                 h = fl.heads()
                 h.reverse()
                 for r in h:
                     for l in fl.read(r).splitlines():
                         if l:
                             n, k = l.split(" ", 1)
                             addtag(self, k, n)
             except KeyError:
                 pass
 
             try:
                 f = self.opener("localtags")
                 for l in f:
                     n, k = l.split(" ", 1)
                     addtag(self, k, n)
             except IOError:
                 pass
 
             self.tagscache['tip'] = self.changelog.tip()
 
         return self.tagscache
 
     def tagslist(self):
         '''return a list of tags ordered by revision'''
         l = []
         for t, n in self.tags().items():
             try:
                 r = self.changelog.rev(n)
             except:
                 r = -2 # sort to the beginning of the list if unknown
             l.append((r, t, n))
         l.sort()
         return [(t, n) for r, t, n in l]
 
     def nodetags(self, node):
         '''return the tags associated with a node'''
         if not self.nodetagscache:
             self.nodetagscache = {}
             for t, n in self.tags().items():
                 self.nodetagscache.setdefault(n, []).append(t)
         return self.nodetagscache.get(node, [])
 
     def lookup(self, key):
         try:
             return self.tags()[key]
         except KeyError:
             try:
                 return self.changelog.lookup(key)
             except:
                 raise repo.RepoError(_("unknown revision '%s'") % key)
 
     def dev(self):
         return os.stat(self.path).st_dev
 
     def local(self):
         return True
 
     def join(self, f):
         return os.path.join(self.path, f)
 
     def wjoin(self, f):
         return os.path.join(self.root, f)
 
     def file(self, f):
         if f[0] == '/':
             f = f[1:]
         return filelog.filelog(self.opener, f)
 
     def getcwd(self):
         return self.dirstate.getcwd()
 
     def wfile(self, f, mode='r'):
         return self.wopener(f, mode)
 
     def wread(self, filename):
         if self.encodepats == None:
             l = []
             for pat, cmd in self.ui.configitems("encode"):
                 mf = util.matcher(self.root, "", [pat], [], [])[1]
                 l.append((mf, cmd))
             self.encodepats = l
 
         data = self.wopener(filename, 'r').read()
 
         for mf, cmd in self.encodepats:
             if mf(filename):
                 self.ui.debug(_("filtering %s through %s\n") % (filename, cmd))
                 data = util.filter(data, cmd)
                 break
 
         return data
 
     def wwrite(self, filename, data, fd=None):
         if self.decodepats == None:
             l = []
             for pat, cmd in self.ui.configitems("decode"):
                 mf = util.matcher(self.root, "", [pat], [], [])[1]
                 l.append((mf, cmd))
             self.decodepats = l
 
         for mf, cmd in self.decodepats:
             if mf(filename):
                 self.ui.debug(_("filtering %s through %s\n") % (filename, cmd))
                 data = util.filter(data, cmd)
                 break
 
         if fd:
             return fd.write(data)
         return self.wopener(filename, 'w').write(data)
 
     def transaction(self):
         tr = self.transhandle
         if tr != None and tr.running():
             return tr.nest()
 
         # save dirstate for undo
         try:
             ds = self.opener("dirstate").read()
         except IOError:
             ds = ""
         self.opener("journal.dirstate", "w").write(ds)
 
         tr = transaction.transaction(self.ui.warn, self.opener,
                                        self.join("journal"),
                                        aftertrans(self.path))
         self.transhandle = tr
         return tr
 
     def recover(self):
         l = self.lock()
         if os.path.exists(self.join("journal")):
             self.ui.status(_("rolling back interrupted transaction\n"))
             transaction.rollback(self.opener, self.join("journal"))
             self.reload()
             return True
         else:
             self.ui.warn(_("no interrupted transaction available\n"))
             return False
 
     def undo(self, wlock=None):
         if not wlock:
             wlock = self.wlock()
         l = self.lock()
         if os.path.exists(self.join("undo")):
             self.ui.status(_("rolling back last transaction\n"))
             transaction.rollback(self.opener, self.join("undo"))
             util.rename(self.join("undo.dirstate"), self.join("dirstate"))
             self.reload()
             self.wreload()
         else:
             self.ui.warn(_("no undo information available\n"))
 
     def wreload(self):
         self.dirstate.read()
 
     def reload(self):
         self.changelog.load()
         self.manifest.load()
         self.tagscache = None
         self.nodetagscache = None
 
     def do_lock(self, lockname, wait, releasefn=None, acquirefn=None):
         try:
             l = lock.lock(self.join(lockname), 0, releasefn)
         except lock.LockHeld, inst:
             if not wait:
                 raise inst
             self.ui.warn(_("waiting for lock held by %s\n") % inst.args[0])
             try:
                 # default to 600 seconds timeout
                 l = lock.lock(self.join(lockname),
                               int(self.ui.config("ui", "timeout") or 600),
                               releasefn)
             except lock.LockHeld, inst:
                 raise util.Abort(_("timeout while waiting for "
                                    "lock held by %s") % inst.args[0])
         if acquirefn:
             acquirefn()
         return l
 
     def lock(self, wait=1):
         return self.do_lock("lock", wait, acquirefn=self.reload)
 
     def wlock(self, wait=1):
         return self.do_lock("wlock", wait,
                             self.dirstate.write,
                             self.wreload)
 
     def checkfilemerge(self, filename, text, filelog, manifest1, manifest2):
         "determine whether a new filenode is needed"
         fp1 = manifest1.get(filename, nullid)
         fp2 = manifest2.get(filename, nullid)
 
         if fp2 != nullid:
             # is one parent an ancestor of the other?
             fpa = filelog.ancestor(fp1, fp2)
             if fpa == fp1:
                 fp1, fp2 = fp2, nullid
             elif fpa == fp2:
                 fp2 = nullid
 
             # is the file unmodified from the parent? report existing entry
             if fp2 == nullid and text == filelog.read(fp1):
                 return (fp1, None, None)
 
         return (None, fp1, fp2)
 
     def rawcommit(self, files, text, user, date, p1=None, p2=None, wlock=None):
         orig_parent = self.dirstate.parents()[0] or nullid
         p1 = p1 or self.dirstate.parents()[0] or nullid
         p2 = p2 or self.dirstate.parents()[1] or nullid
         c1 = self.changelog.read(p1)
         c2 = self.changelog.read(p2)
         m1 = self.manifest.read(c1[0])
         mf1 = self.manifest.readflags(c1[0])
         m2 = self.manifest.read(c2[0])
         changed = []
 
         if orig_parent == p1:
             update_dirstate = 1
         else:
             update_dirstate = 0
 
         if not wlock:
             wlock = self.wlock()
         l = self.lock()
         tr = self.transaction()
         mm = m1.copy()
         mfm = mf1.copy()
         linkrev = self.changelog.count()
         for f in files:
             try:
                 t = self.wread(f)
                 tm = util.is_exec(self.wjoin(f), mfm.get(f, False))
                 r = self.file(f)
                 mfm[f] = tm
 
                 (entry, fp1, fp2) = self.checkfilemerge(f, t, r, m1, m2)
                 if entry:
                     mm[f] = entry
                     continue
 
                 mm[f] = r.add(t, {}, tr, linkrev, fp1, fp2)
                 changed.append(f)
                 if update_dirstate:
                     self.dirstate.update([f], "n")
             except IOError:
                 try:
                     del mm[f]
                     del mfm[f]
                     if update_dirstate:
                         self.dirstate.forget([f])
                 except:
                     # deleted from p2?
                     pass
 
         mnode = self.manifest.add(mm, mfm, tr, linkrev, c1[0], c2[0])
         user = user or self.ui.username()
         n = self.changelog.add(mnode, changed, text, tr, p1, p2, user, date)
         tr.close()
         if update_dirstate:
             self.dirstate.setparents(n, nullid)
 
     def commit(self, files=None, text="", user=None, date=None,
                match=util.always, force=False, lock=None, wlock=None):
         commit = []
         remove = []
         changed = []
 
         if files:
             for f in files:
                 s = self.dirstate.state(f)
                 if s in 'nmai':
                     commit.append(f)
                 elif s == 'r':
                     remove.append(f)
                 else:
                     self.ui.warn(_("%s not tracked!\n") % f)
         else:
             modified, added, removed, deleted, unknown = self.changes(match=match)
             commit = modified + added
             remove = removed
 
         p1, p2 = self.dirstate.parents()
         c1 = self.changelog.read(p1)
         c2 = self.changelog.read(p2)
         m1 = self.manifest.read(c1[0])
         mf1 = self.manifest.readflags(c1[0])
         m2 = self.manifest.read(c2[0])
 
         if not commit and not remove and not force and p2 == nullid:
             self.ui.status(_("nothing changed\n"))
             return None
 
         xp1 = hex(p1)
         if p2 == nullid: xp2 = ''
         else: xp2 = hex(p2)
 
         self.hook("precommit", throw=True, parent1=xp1, parent2=xp2)
 
         if not wlock:
             wlock = self.wlock()
         if not lock:
             lock = self.lock()
         tr = self.transaction()
 
         # check in files
         new = {}
         linkrev = self.changelog.count()
         commit.sort()
         for f in commit:
             self.ui.note(f + "\n")
             try:
                 mf1[f] = util.is_exec(self.wjoin(f), mf1.get(f, False))
                 t = self.wread(f)
             except IOError:
                 self.ui.warn(_("trouble committing %s!\n") % f)
                 raise
 
             r = self.file(f)
 
             meta = {}
             cp = self.dirstate.copied(f)
             if cp:
                 meta["copy"] = cp
                 meta["copyrev"] = hex(m1.get(cp, m2.get(cp, nullid)))
                 self.ui.debug(_(" %s: copy %s:%s\n") % (f, cp, meta["copyrev"]))
                 fp1, fp2 = nullid, nullid
             else:
                 entry, fp1, fp2 = self.checkfilemerge(f, t, r, m1, m2)
                 if entry:
                     new[f] = entry
                     continue
 
             new[f] = r.add(t, meta, tr, linkrev, fp1, fp2)
             # remember what we've added so that we can later calculate
             # the files to pull from a set of changesets
             changed.append(f)
 
         # update manifest
         m1 = m1.copy()
         m1.update(new)
         for f in remove:
             if f in m1:
                 del m1[f]
         mn = self.manifest.add(m1, mf1, tr, linkrev, c1[0], c2[0],
                                (new, remove))
 
         # add changeset
         new = new.keys()
         new.sort()
 
         if not text:
             edittext = [""]
             if p2 != nullid:
                 edittext.append("HG: branch merge")
             edittext.extend(["HG: changed %s" % f for f in changed])
             edittext.extend(["HG: removed %s" % f for f in remove])
             if not changed and not remove:
                 edittext.append("HG: no files changed")
             edittext.append("")
             # run editor in the repository root
             olddir = os.getcwd()
             os.chdir(self.root)
             edittext = self.ui.edit("\n".join(edittext))
             os.chdir(olddir)
             if not edittext.rstrip():
                 return None
             text = edittext
 
         user = user or self.ui.username()
         n = self.changelog.add(mn, changed + remove, text, tr, p1, p2, user, date)
         self.hook('pretxncommit', throw=True, node=hex(n), parent1=xp1,
                   parent2=xp2)
         tr.close()
 
         self.dirstate.setparents(n)
         self.dirstate.update(new, "n")
         self.dirstate.forget(remove)
 
         self.hook("commit", node=hex(n), parent1=xp1, parent2=xp2)
         return n
 
     def walk(self, node=None, files=[], match=util.always):
         if node:
             fdict = dict.fromkeys(files)
             for fn in self.manifest.read(self.changelog.read(node)[0]):
                 fdict.pop(fn, None)
                 if match(fn):
                     yield 'm', fn
             for fn in fdict:
                 self.ui.warn(_('%s: No such file in rev %s\n') % (
                     util.pathto(self.getcwd(), fn), short(node)))
         else:
             for src, fn in self.dirstate.walk(files, match):
                 yield src, fn
 
     def changes(self, node1=None, node2=None, files=[], match=util.always,
                 wlock=None):
         """return changes between two nodes or node and working directory
 
         If node1 is None, use the first dirstate parent instead.
         If node2 is None, compare node1 with working directory.
         """
 
         def fcmp(fn, mf):
             t1 = self.wread(fn)
             t2 = self.file(fn).read(mf.get(fn, nullid))
             return cmp(t1, t2)
 
         def mfmatches(node):
             change = self.changelog.read(node)
             mf = dict(self.manifest.read(change[0]))
             for fn in mf.keys():
                 if not match(fn):
                     del mf[fn]
             return mf
 
         if node1:
             # read the manifest from node1 before the manifest from node2,
             # so that we'll hit the manifest cache if we're going through
             # all the revisions in parent->child order.
             mf1 = mfmatches(node1)
 
         # are we comparing the working directory?
         if not node2:
             if not wlock:
                 try:
                     wlock = self.wlock(wait=0)
                 except lock.LockException:
                     wlock = None
             lookup, modified, added, removed, deleted, unknown = (
                 self.dirstate.changes(files, match))
 
             # are we comparing working dir against its parent?
             if not node1:
                 if lookup:
                     # do a full compare of any files that might have changed
                     mf2 = mfmatches(self.dirstate.parents()[0])
                     for f in lookup:
                         if fcmp(f, mf2):
                             modified.append(f)
                         elif wlock is not None:
                             self.dirstate.update([f], "n")
             else:
                 # we are comparing working dir against non-parent
                 # generate a pseudo-manifest for the working dir
                 mf2 = mfmatches(self.dirstate.parents()[0])
                 for f in lookup + modified + added:
                     mf2[f] = ""
                 for f in removed:
                     if f in mf2:
                         del mf2[f]
         else:
             # we are comparing two revisions
             deleted, unknown = [], []
             mf2 = mfmatches(node2)
 
         if node1:
             # flush lists from dirstate before comparing manifests
             modified, added = [], []
 
             for fn in mf2:
                 if mf1.has_key(fn):
                     if mf1[fn] != mf2[fn] and (mf2[fn] != "" or fcmp(fn, mf1)):
                         modified.append(fn)
                     del mf1[fn]
                 else:
                     added.append(fn)
 
             removed = mf1.keys()
 
         # sort and return results:
         for l in modified, added, removed, deleted, unknown:
             l.sort()
         return (modified, added, removed, deleted, unknown)
 
     def add(self, list, wlock=None):
         if not wlock:
             wlock = self.wlock()
         for f in list:
             p = self.wjoin(f)
             if not os.path.exists(p):
                 self.ui.warn(_("%s does not exist!\n") % f)
             elif not os.path.isfile(p):
                 self.ui.warn(_("%s not added: only files supported currently\n")
                              % f)
             elif self.dirstate.state(f) in 'an':
                 self.ui.warn(_("%s already tracked!\n") % f)
             else:
                 self.dirstate.update([f], "a")
 
     def forget(self, list, wlock=None):
         if not wlock:
             wlock = self.wlock()
         for f in list:
             if self.dirstate.state(f) not in 'ai':
                 self.ui.warn(_("%s not added!\n") % f)
             else:
                 self.dirstate.forget([f])
 
     def remove(self, list, unlink=False, wlock=None):
         if unlink:
             for f in list:
                 try:
                     util.unlink(self.wjoin(f))
                 except OSError, inst:
                     if inst.errno != errno.ENOENT:
                         raise
         if not wlock:
             wlock = self.wlock()
         for f in list:
             p = self.wjoin(f)
             if os.path.exists(p):
                 self.ui.warn(_("%s still exists!\n") % f)
             elif self.dirstate.state(f) == 'a':
                 self.dirstate.forget([f])
             elif f not in self.dirstate:
                 self.ui.warn(_("%s not tracked!\n") % f)
             else:
                 self.dirstate.update([f], "r")
 
     def undelete(self, list, wlock=None):
         p = self.dirstate.parents()[0]
         mn = self.changelog.read(p)[0]
         mf = self.manifest.readflags(mn)
         m = self.manifest.read(mn)
         if not wlock:
             wlock = self.wlock()
         for f in list:
             if self.dirstate.state(f) not in  "r":
                 self.ui.warn("%s not removed!\n" % f)
             else:
                 t = self.file(f).read(m[f])
                 self.wwrite(f, t)
                 util.set_exec(self.wjoin(f), mf[f])
                 self.dirstate.update([f], "n")
 
     def copy(self, source, dest, wlock=None):
         p = self.wjoin(dest)
         if not os.path.exists(p):
             self.ui.warn(_("%s does not exist!\n") % dest)
         elif not os.path.isfile(p):
             self.ui.warn(_("copy failed: %s is not a file\n") % dest)
         else:
             if not wlock:
                 wlock = self.wlock()
             if self.dirstate.state(dest) == '?':
                 self.dirstate.update([dest], "a")
             self.dirstate.copy(source, dest)
 
     def heads(self, start=None):
         heads = self.changelog.heads(start)
         # sort the output in rev descending order
         heads = [(-self.changelog.rev(h), h) for h in heads]
         heads.sort()
         return [n for (r, n) in heads]
 
     # branchlookup returns a dict giving a list of branches for
     # each head.  A branch is defined as the tag of a node or
     # the branch of the node's parents.  If a node has multiple
     # branch tags, tags are eliminated if they are visible from other
     # branch tags.
     #
     # So, for this graph:  a->b->c->d->e
     #                       \         /
     #                        aa -----/
     # a has tag 2.6.12
     # d has tag 2.6.13
     # e would have branch tags for 2.6.12 and 2.6.13.  Because the node
     # for 2.6.12 can be reached from the node 2.6.13, that is eliminated
     # from the list.
     #
     # It is possible that more than one head will have the same branch tag.
     # callers need to check the result for multiple heads under the same
     # branch tag if that is a problem for them (ie checkout of a specific
     # branch).
     #
     # passing in a specific branch will limit the depth of the search
     # through the parents.  It won't limit the branches returned in the
     # result though.
     def branchlookup(self, heads=None, branch=None):
         if not heads:
             heads = self.heads()
         headt = [ h for h in heads ]
         chlog = self.changelog
         branches = {}
         merges = []
         seenmerge = {}
 
         # traverse the tree once for each head, recording in the branches
         # dict which tags are visible from this head.  The branches
         # dict also records which tags are visible from each tag
         # while we traverse.
         while headt or merges:
             if merges:
                 n, found = merges.pop()
                 visit = [n]
             else:
                 h = headt.pop()
                 visit = [h]
                 found = [h]
                 seen = {}
             while visit:
                 n = visit.pop()
                 if n in seen:
                     continue
                 pp = chlog.parents(n)
                 tags = self.nodetags(n)
                 if tags:
                     for x in tags:
                         if x == 'tip':
                             continue
                         for f in found:
                             branches.setdefault(f, {})[n] = 1
                         branches.setdefault(n, {})[n] = 1
                         break
                     if n not in found:
                         found.append(n)
                     if branch in tags:
                         continue
                 seen[n] = 1
                 if pp[1] != nullid and n not in seenmerge:
                     merges.append((pp[1], [x for x in found]))
                     seenmerge[n] = 1
                 if pp[0] != nullid:
                     visit.append(pp[0])
         # traverse the branches dict, eliminating branch tags from each
         # head that are visible from another branch tag for that head.
         out = {}
         viscache = {}
         for h in heads:
             def visible(node):
                 if node in viscache:
                     return viscache[node]
                 ret = {}
                 visit = [node]
                 while visit:
                     x = visit.pop()
                     if x in viscache:
                         ret.update(viscache[x])
                     elif x not in ret:
                         ret[x] = 1
                         if x in branches:
                             visit[len(visit):] = branches[x].keys()
                 viscache[node] = ret
                 return ret
             if h not in branches:
                 continue
             # O(n^2), but somewhat limited.  This only searches the
             # tags visible from a specific head, not all the tags in the
             # whole repo.
             for b in branches[h]:
                 vis = False
                 for bb in branches[h].keys():
                     if b != bb:
                         if b in visible(bb):
                             vis = True
                             break
                 if not vis:
                     l = out.setdefault(h, [])
                     l[len(l):] = self.nodetags(b)
         return out
 
     def branches(self, nodes):
         if not nodes:
             nodes = [self.changelog.tip()]
         b = []
         for n in nodes:
             t = n
             while n:
                 p = self.changelog.parents(n)
                 if p[1] != nullid or p[0] == nullid:
                     b.append((t, n, p[0], p[1]))
                     break
                 n = p[0]
         return b
 
     def between(self, pairs):
         r = []
 
         for top, bottom in pairs:
             n, l, i = top, [], 0
             f = 1
 
             while n != bottom:
                 p = self.changelog.parents(n)[0]
                 if i == f:
                     l.append(n)
                     f = f * 2
                 n = p
                 i += 1
 
             r.append(l)
 
         return r
 
     def findincoming(self, remote, base=None, heads=None, force=False):
         m = self.changelog.nodemap
         search = []
         fetch = {}
         seen = {}
         seenbranch = {}
         if base == None:
             base = {}
 
         # assume we're closer to the tip than the root
         # and start by examining the heads
         self.ui.status(_("searching for changes\n"))
 
         if not heads:
             heads = remote.heads()
 
         unknown = []
         for h in heads:
             if h not in m:
                 unknown.append(h)
             else:
                 base[h] = 1
 
         if not unknown:
             return []
 
         rep = {}
         reqcnt = 0
 
         # search through remote branches
         # a 'branch' here is a linear segment of history, with four parts:
         # head, root, first parent, second parent
         # (a branch always has two parents (or none) by definition)
         unknown = remote.branches(unknown)
         while unknown:
             r = []
             while unknown:
                 n = unknown.pop(0)
                 if n[0] in seen:
                     continue
 
                 self.ui.debug(_("examining %s:%s\n")
                               % (short(n[0]), short(n[1])))
                 if n[0] == nullid:
                     break
                 if n in seenbranch:
                     self.ui.debug(_("branch already found\n"))
                     continue
                 if n[1] and n[1] in m: # do we know the base?
                     self.ui.debug(_("found incomplete branch %s:%s\n")
                                   % (short(n[0]), short(n[1])))
                     search.append(n) # schedule branch range for scanning
                     seenbranch[n] = 1
                 else:
                     if n[1] not in seen and n[1] not in fetch:
                         if n[2] in m and n[3] in m:
                             self.ui.debug(_("found new changeset %s\n") %
                                           short(n[1]))
                             fetch[n[1]] = 1 # earliest unknown
                             base[n[2]] = 1 # latest known
                             continue
 
                     for a in n[2:4]:
                         if a not in rep:
                             r.append(a)
                             rep[a] = 1
 
                 seen[n[0]] = 1
 
             if r:
                 reqcnt += 1
                 self.ui.debug(_("request %d: %s\n") %
                             (reqcnt, " ".join(map(short, r))))
                 for p in range(0, len(r), 10):
                     for b in remote.branches(r[p:p+10]):
                         self.ui.debug(_("received %s:%s\n") %
                                       (short(b[0]), short(b[1])))
                         if b[0] in m:
                             self.ui.debug(_("found base node %s\n")
                                           % short(b[0]))
                             base[b[0]] = 1
                         elif b[0] not in seen:
                             unknown.append(b)
 
         # do binary search on the branches we found
         while search:
             n = search.pop(0)
             reqcnt += 1
             l = remote.between([(n[0], n[1])])[0]
             l.append(n[1])
             p = n[0]
             f = 1
             for i in l:
                 self.ui.debug(_("narrowing %d:%d %s\n") % (f, len(l), short(i)))
                 if i in m:
                     if f <= 2:
                         self.ui.debug(_("found new branch changeset %s\n") %
                                           short(p))
                         fetch[p] = 1
                         base[i] = 1
                     else:
                         self.ui.debug(_("narrowed branch search to %s:%s\n")
                                       % (short(p), short(i)))
                         search.append((p, i))
                     break
                 p, f = i, f * 2
 
         # sanity check our fetch list
         for f in fetch.keys():
             if f in m:
                 raise repo.RepoError(_("already have changeset ") + short(f[:4]))
 
         if base.keys() == [nullid]:
             if force:
                 self.ui.warn(_("warning: repository is unrelated\n"))
             else:
                 raise util.Abort(_("repository is unrelated"))
 
         self.ui.note(_("found new changesets starting at ") +
                      " ".join([short(f) for f in fetch]) + "\n")
 
         self.ui.debug(_("%d total queries\n") % reqcnt)
 
         return fetch.keys()
 
     def findoutgoing(self, remote, base=None, heads=None, force=False):
         if base == None:
             base = {}
             self.findincoming(remote, base, heads, force=force)
 
         self.ui.debug(_("common changesets up to ")
                       + " ".join(map(short, base.keys())) + "\n")
 
         remain = dict.fromkeys(self.changelog.nodemap)
 
         # prune everything remote has from the tree
         del remain[nullid]
         remove = base.keys()
         while remove:
             n = remove.pop(0)
             if n in remain:
                 del remain[n]
                 for p in self.changelog.parents(n):
                     remove.append(p)
 
         # find every node whose parents have been pruned
         subset = []
         for n in remain:
             p1, p2 = self.changelog.parents(n)
             if p1 not in remain and p2 not in remain:
                 subset.append(n)
 
         # this is the set of all roots we have to push
         return subset
 
     def pull(self, remote, heads=None, force=False):
         l = self.lock()
 
         # if we have an empty repo, fetch everything
         if self.changelog.tip() == nullid:
             self.ui.status(_("requesting all changes\n"))
             fetch = [nullid]
         else:
             fetch = self.findincoming(remote, force=force)
 
         if not fetch:
             self.ui.status(_("no changes found\n"))
             return 1
 
         if heads is None:
             cg = remote.changegroup(fetch, 'pull')
         else:
             cg = remote.changegroupsubset(fetch, heads, 'pull')
         return self.addchangegroup(cg)
 
     def push(self, remote, force=False, revs=None):
         lock = remote.lock()
 
         base = {}
         heads = remote.heads()
         inc = self.findincoming(remote, base, heads, force=force)
         if not force and inc:
             self.ui.warn(_("abort: unsynced remote changes!\n"))
             self.ui.status(_("(did you forget to sync? use push -f to force)\n"))
             return 1
 
         update = self.findoutgoing(remote, base)
         if revs is not None:
             msng_cl, bases, heads = self.changelog.nodesbetween(update, revs)
         else:
             bases, heads = update, self.changelog.heads()
 
         if not bases:
             self.ui.status(_("no changes found\n"))
             return 1
         elif not force:
             if len(bases) < len(heads):
                 self.ui.warn(_("abort: push creates new remote branches!\n"))
                 self.ui.status(_("(did you forget to merge?"
                                  " use push -f to force)\n"))
                 return 1
 
         if revs is None:
             cg = self.changegroup(update, 'push')
         else:
             cg = self.changegroupsubset(update, revs, 'push')
         return remote.addchangegroup(cg)
 
     def changegroupsubset(self, bases, heads, source):
         """This function generates a changegroup consisting of all the nodes
         that are descendents of any of the bases, and ancestors of any of
         the heads.
 
         It is fairly complex as determining which filenodes and which
         manifest nodes need to be included for the changeset to be complete
         is non-trivial.
 
         Another wrinkle is doing the reverse, figuring out which changeset in
         the changegroup a particular filenode or manifestnode belongs to."""
 
         self.hook('preoutgoing', throw=True, source=source)
 
         # Set up some initial variables
         # Make it easy to refer to self.changelog
         cl = self.changelog
         # msng is short for missing - compute the list of changesets in this
         # changegroup.
         msng_cl_lst, bases, heads = cl.nodesbetween(bases, heads)
         # Some bases may turn out to be superfluous, and some heads may be
         # too.  nodesbetween will return the minimal set of bases and heads
         # necessary to re-create the changegroup.
 
         # Known heads are the list of heads that it is assumed the recipient
         # of this changegroup will know about.
         knownheads = {}
         # We assume that all parents of bases are known heads.
         for n in bases:
             for p in cl.parents(n):
                 if p != nullid:
                     knownheads[p] = 1
         knownheads = knownheads.keys()
         if knownheads:
             # Now that we know what heads are known, we can compute which
             # changesets are known.  The recipient must know about all
             # changesets required to reach the known heads from the null
             # changeset.
             has_cl_set, junk, junk = cl.nodesbetween(None, knownheads)
             junk = None
             # Transform the list into an ersatz set.
             has_cl_set = dict.fromkeys(has_cl_set)
         else:
             # If there were no known heads, the recipient cannot be assumed to
             # know about any changesets.
             has_cl_set = {}
 
         # Make it easy to refer to self.manifest
         mnfst = self.manifest
         # We don't know which manifests are missing yet
         msng_mnfst_set = {}
         # Nor do we know which filenodes are missing.
         msng_filenode_set = {}
 
         junk = mnfst.index[mnfst.count() - 1] # Get around a bug in lazyindex
         junk = None
 
         # A changeset always belongs to itself, so the changenode lookup
         # function for a changenode is identity.
         def identity(x):
             return x
 
         # A function generating function.  Sets up an environment for the
         # inner function.
         def cmp_by_rev_func(revlog):
             # Compare two nodes by their revision number in the environment's
             # revision history.  Since the revision number both represents the
             # most efficient order to read the nodes in, and represents a
             # topological sorting of the nodes, this function is often useful.
             def cmp_by_rev(a, b):
                 return cmp(revlog.rev(a), revlog.rev(b))
             return cmp_by_rev
 
         # If we determine that a particular file or manifest node must be a
         # node that the recipient of the changegroup will already have, we can
         # also assume the recipient will have all the parents.  This function
         # prunes them from the set of missing nodes.
         def prune_parents(revlog, hasset, msngset):
             haslst = hasset.keys()
             haslst.sort(cmp_by_rev_func(revlog))
             for node in haslst:
                 parentlst = [p for p in revlog.parents(node) if p != nullid]
                 while parentlst:
                     n = parentlst.pop()
                     if n not in hasset:
                         hasset[n] = 1
                         p = [p for p in revlog.parents(n) if p != nullid]
                         parentlst.extend(p)
             for n in hasset:
                 msngset.pop(n, None)
 
         # This is a function generating function used to set up an environment
         # for the inner function to execute in.
         def manifest_and_file_collector(changedfileset):
             # This is an information gathering function that gathers
             # information from each changeset node that goes out as part of
             # the changegroup.  The information gathered is a list of which
             # manifest nodes are potentially required (the recipient may
             # already have them) and total list of all files which were
             # changed in any changeset in the changegroup.
             #
             # We also remember the first changenode we saw any manifest
             # referenced by so we can later determine which changenode 'owns'
             # the manifest.
             def collect_manifests_and_files(clnode):
                 c = cl.read(clnode)
                 for f in c[3]:
                     # This is to make sure we only have one instance of each
                     # filename string for each filename.
                     changedfileset.setdefault(f, f)
                 msng_mnfst_set.setdefault(c[0], clnode)
             return collect_manifests_and_files
 
         # Figure out which manifest nodes (of the ones we think might be part
         # of the changegroup) the recipient must know about and remove them
         # from the changegroup.
         def prune_manifests():
             has_mnfst_set = {}
             for n in msng_mnfst_set:
                 # If a 'missing' manifest thinks it belongs to a changenode
                 # the recipient is assumed to have, obviously the recipient
                 # must have that manifest.
                 linknode = cl.node(mnfst.linkrev(n))
                 if linknode in has_cl_set:
                     has_mnfst_set[n] = 1
             prune_parents(mnfst, has_mnfst_set, msng_mnfst_set)
 
         # Use the information collected in collect_manifests_and_files to say
         # which changenode any manifestnode belongs to.
         def lookup_manifest_link(mnfstnode):
             return msng_mnfst_set[mnfstnode]
 
         # A function generating function that sets up the initial environment
         # the inner function.
         def filenode_collector(changedfiles):
             next_rev = [0]
             # This gathers information from each manifestnode included in the
             # changegroup about which filenodes the manifest node references
             # so we can include those in the changegroup too.
             #
             # It also remembers which changenode each filenode belongs to.  It
             # does this by assuming the a filenode belongs to the changenode
             # the first manifest that references it belongs to.
             def collect_msng_filenodes(mnfstnode):
                 r = mnfst.rev(mnfstnode)
                 if r == next_rev[0]:
                     # If the last rev we looked at was the one just previous,
                     # we only need to see a diff.
                     delta = mdiff.patchtext(mnfst.delta(mnfstnode))
                     # For each line in the delta
                     for dline in delta.splitlines():
                         # get the filename and filenode for that line
                         f, fnode = dline.split('\0')
                         fnode = bin(fnode[:40])
                         f = changedfiles.get(f, None)
                         # And if the file is in the list of files we care
                         # about.
                         if f is not None:
                             # Get the changenode this manifest belongs to
                             clnode = msng_mnfst_set[mnfstnode]
                             # Create the set of filenodes for the file if
                             # there isn't one already.
                             ndset = msng_filenode_set.setdefault(f, {})
                             # And set the filenode's changelog node to the
                             # manifest's if it hasn't been set already.
                             ndset.setdefault(fnode, clnode)
                 else:
                     # Otherwise we need a full manifest.
                     m = mnfst.read(mnfstnode)
                     # For every file in we care about.
                     for f in changedfiles:
                         fnode = m.get(f, None)
                         # If it's in the manifest
                         if fnode is not None:
                             # See comments above.
                             clnode = msng_mnfst_set[mnfstnode]
                             ndset = msng_filenode_set.setdefault(f, {})
                             ndset.setdefault(fnode, clnode)
                 # Remember the revision we hope to see next.
                 next_rev[0] = r + 1
             return collect_msng_filenodes
 
         # We have a list of filenodes we think we need for a file, lets remove
         # all those we now the recipient must have.
         def prune_filenodes(f, filerevlog):
             msngset = msng_filenode_set[f]
             hasset = {}
             # If a 'missing' filenode thinks it belongs to a changenode we
             # assume the recipient must have, then the recipient must have
             # that filenode.
             for n in msngset:
                 clnode = cl.node(filerevlog.linkrev(n))
                 if clnode in has_cl_set:
                     hasset[n] = 1
             prune_parents(filerevlog, hasset, msngset)
 
         # A function generator function that sets up the a context for the
         # inner function.
         def lookup_filenode_link_func(fname):
             msngset = msng_filenode_set[fname]
             # Lookup the changenode the filenode belongs to.
             def lookup_filenode_link(fnode):
                 return msngset[fnode]
             return lookup_filenode_link
 
         # Now that we have all theses utility functions to help out and
         # logically divide up the task, generate the group.
         def gengroup():
             # The set of changed files starts empty.
             changedfiles = {}
             # Create a changenode group generator that will call our functions
             # back to lookup the owning changenode and collect information.
             group = cl.group(msng_cl_lst, identity,
                              manifest_and_file_collector(changedfiles))
             for chnk in group:
                 yield chnk
 
             # The list of manifests has been collected by the generator
             # calling our functions back.
             prune_manifests()
             msng_mnfst_lst = msng_mnfst_set.keys()
             # Sort the manifestnodes by revision number.
             msng_mnfst_lst.sort(cmp_by_rev_func(mnfst))
             # Create a generator for the manifestnodes that calls our lookup
             # and data collection functions back.
             group = mnfst.group(msng_mnfst_lst, lookup_manifest_link,
                                 filenode_collector(changedfiles))
             for chnk in group:
                 yield chnk
 
             # These are no longer needed, dereference and toss the memory for
             # them.
             msng_mnfst_lst = None
             msng_mnfst_set.clear()
 
             changedfiles = changedfiles.keys()
             changedfiles.sort()
             # Go through all our files in order sorted by name.
             for fname in changedfiles:
                 filerevlog = self.file(fname)
                 # Toss out the filenodes that the recipient isn't really
                 # missing.
                 if msng_filenode_set.has_key(fname):
                     prune_filenodes(fname, filerevlog)
                     msng_filenode_lst = msng_filenode_set[fname].keys()
                 else:
                     msng_filenode_lst = []
                 # If any filenodes are left, generate the group for them,
                 # otherwise don't bother.
                 if len(msng_filenode_lst) > 0:
-                    yield struct.pack(">l", len(fname) + 4) + fname
+                    yield changegroup.genchunk(fname)
                     # Sort the filenodes by their revision #
                     msng_filenode_lst.sort(cmp_by_rev_func(filerevlog))
                     # Create a group generator and only pass in a changenode
                     # lookup function as we need to collect no information
                     # from filenodes.
                     group = filerevlog.group(msng_filenode_lst,
                                              lookup_filenode_link_func(fname))
                     for chnk in group:
                         yield chnk
                 if msng_filenode_set.has_key(fname):
                     # Don't need this anymore, toss it to free memory.
                     del msng_filenode_set[fname]
             # Signal that no more groups are left.
-            yield struct.pack(">l", 0)
+            yield changegroup.closechunk()
 
             self.hook('outgoing', node=hex(msng_cl_lst[0]), source=source)
 
         return util.chunkbuffer(gengroup())
 
     def changegroup(self, basenodes, source):
         """Generate a changegroup of all nodes that we have that a recipient
         doesn't.
 
         This is much easier than the previous function as we can assume that
         the recipient has any changenode we aren't sending them."""
 
         self.hook('preoutgoing', throw=True, source=source)
 
         cl = self.changelog
         nodes = cl.nodesbetween(basenodes, None)[0]
         revset = dict.fromkeys([cl.rev(n) for n in nodes])
 
         def identity(x):
             return x
 
         def gennodelst(revlog):
             for r in xrange(0, revlog.count()):
                 n = revlog.node(r)
                 if revlog.linkrev(n) in revset:
                     yield n
 
         def changed_file_collector(changedfileset):
             def collect_changed_files(clnode):
                 c = cl.read(clnode)
                 for fname in c[3]:
                     changedfileset[fname] = 1
             return collect_changed_files
 
         def lookuprevlink_func(revlog):
             def lookuprevlink(n):
                 return cl.node(revlog.linkrev(n))
             return lookuprevlink
 
         def gengroup():
             # construct a list of all changed files
             changedfiles = {}
 
             for chnk in cl.group(nodes, identity,
                                  changed_file_collector(changedfiles)):
                 yield chnk
             changedfiles = changedfiles.keys()
             changedfiles.sort()
 
             mnfst = self.manifest
             nodeiter = gennodelst(mnfst)
             for chnk in mnfst.group(nodeiter, lookuprevlink_func(mnfst)):
                 yield chnk
 
             for fname in changedfiles:
                 filerevlog = self.file(fname)
                 nodeiter = gennodelst(filerevlog)
                 nodeiter = list(nodeiter)
                 if nodeiter:
-                    yield struct.pack(">l", len(fname) + 4) + fname
+                    yield changegroup.genchunk(fname)
                     lookup = lookuprevlink_func(filerevlog)
                     for chnk in filerevlog.group(nodeiter, lookup):
                         yield chnk
 
-            yield struct.pack(">l", 0)
+            yield changegroup.closechunk()
             self.hook('outgoing', node=hex(nodes[0]), source=source)
 
         return util.chunkbuffer(gengroup())
 
     def addchangegroup(self, source):
 
-        def getchunk():
-            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 repo.RepoError(_("premature EOF reading chunk"
-                                       " (got %d bytes, expected %d)")
-                                     % (len(d), l - 4))
-            return d
-
-        def getgroup():
-            while 1:
-                c = getchunk()
-                if not c:
-                    break
-                yield c
-
         def csmap(x):
             self.ui.debug(_("add changeset %s\n") % short(x))
             return self.changelog.count()
 
         def revmap(x):
             return self.changelog.rev(x)
 
         if not source:
             return
 
         self.hook('prechangegroup', throw=True)
 
         changesets = files = revisions = 0
 
         tr = self.transaction()
 
         oldheads = len(self.changelog.heads())
 
         # pull off the changeset group
         self.ui.status(_("adding changesets\n"))
         co = self.changelog.tip()
-        cn = self.changelog.addgroup(getgroup(), csmap, tr, 1) # unique
+        chunkiter = changegroup.chunkiter(source)
+        cn = self.changelog.addgroup(chunkiter, csmap, tr, 1) # unique
         cnr, cor = map(self.changelog.rev, (cn, co))
         if cn == nullid:
             cnr = cor
         changesets = cnr - cor
 
         # pull off the manifest group
         self.ui.status(_("adding manifests\n"))
         mm = self.manifest.tip()
-        mo = self.manifest.addgroup(getgroup(), revmap, tr)
+        chunkiter = changegroup.chunkiter(source)
+        mo = self.manifest.addgroup(chunkiter, revmap, tr)
 
         # process the files
         self.ui.status(_("adding file changes\n"))
         while 1:
-            f = getchunk()
+            f = changegroup.getchunk(source)
             if not f:
                 break
             self.ui.debug(_("adding %s revisions\n") % f)
             fl = self.file(f)
             o = fl.count()
-            n = fl.addgroup(getgroup(), revmap, tr)
+            chunkiter = changegroup.chunkiter(source)
+            n = fl.addgroup(chunkiter, revmap, tr)
             revisions += fl.count() - o
             files += 1
 
         newheads = len(self.changelog.heads())
         heads = ""
         if oldheads and newheads > oldheads:
             heads = _(" (+%d heads)") % (newheads - oldheads)
 
         self.ui.status(_("added %d changesets"
                          " with %d changes to %d files%s\n")
                          % (changesets, revisions, files, heads))
 
         self.hook('pretxnchangegroup', throw=True,
                   node=hex(self.changelog.node(cor+1)))
 
         tr.close()
 
         if changesets > 0:
             self.hook("changegroup", node=hex(self.changelog.node(cor+1)))
 
             for i in range(cor + 1, cnr + 1):
                 self.hook("incoming", node=hex(self.changelog.node(i)))
 
     def update(self, node, allow=False, force=False, choose=None,
                moddirstate=True, forcemerge=False, wlock=None):
         pl = self.dirstate.parents()
         if not force and pl[1] != nullid:
             self.ui.warn(_("aborting: outstanding uncommitted merges\n"))
             return 1
 
         err = False
 
         p1, p2 = pl[0], node
         pa = self.changelog.ancestor(p1, p2)
         m1n = self.changelog.read(p1)[0]
         m2n = self.changelog.read(p2)[0]
         man = self.manifest.ancestor(m1n, m2n)
         m1 = self.manifest.read(m1n)
         mf1 = self.manifest.readflags(m1n)
         m2 = self.manifest.read(m2n).copy()
         mf2 = self.manifest.readflags(m2n)
         ma = self.manifest.read(man)
         mfa = self.manifest.readflags(man)
 
         modified, added, removed, deleted, unknown = self.changes()
 
         # is this a jump, or a merge?  i.e. is there a linear path
         # from p1 to p2?
         linear_path = (pa == p1 or pa == p2)
 
         if allow and linear_path:
             raise util.Abort(_("there is nothing to merge, "
                                "just use 'hg update'"))
         if allow and not forcemerge:
             if modified or added or removed:
                 raise util.Abort(_("outstanding uncommited changes"))
         if not forcemerge and not force:
             for f in unknown:
                 if f in m2:
                     t1 = self.wread(f)
                     t2 = self.file(f).read(m2[f])
                     if cmp(t1, t2) != 0:
                         raise util.Abort(_("'%s' already exists in the working"
                                            " dir and differs from remote") % f)
 
         # resolve the manifest to determine which files
         # we care about merging
         self.ui.note(_("resolving manifests\n"))
         self.ui.debug(_(" force %s allow %s moddirstate %s linear %s\n") %
                       (force, allow, moddirstate, linear_path))
         self.ui.debug(_(" ancestor %s local %s remote %s\n") %
                       (short(man), short(m1n), short(m2n)))
 
         merge = {}
         get = {}
         remove = []
 
         # construct a working dir manifest
         mw = m1.copy()
         mfw = mf1.copy()
         umap = dict.fromkeys(unknown)
 
         for f in added + modified + unknown:
             mw[f] = ""
             mfw[f] = util.is_exec(self.wjoin(f), mfw.get(f, False))
 
         if moddirstate and not wlock:
             wlock = self.wlock()
 
         for f in deleted + removed:
             if f in mw:
                 del mw[f]
 
             # If we're jumping between revisions (as opposed to merging),
             # and if neither the working directory nor the target rev has
             # the file, then we need to remove it from the dirstate, to
             # prevent the dirstate from listing the file when it is no
             # longer in the manifest.
             if moddirstate and linear_path and f not in m2:
                 self.dirstate.forget((f,))
 
         # Compare manifests
         for f, n in mw.iteritems():
             if choose and not choose(f):
                 continue
             if f in m2:
                 s = 0
 
                 # is the wfile new since m1, and match m2?
                 if f not in m1:
                     t1 = self.wread(f)
                     t2 = self.file(f).read(m2[f])
                     if cmp(t1, t2) == 0:
                         n = m2[f]
                     del t1, t2
 
                 # are files different?
                 if n != m2[f]:
                     a = ma.get(f, nullid)
                     # are both different from the ancestor?
                     if n != a and m2[f] != a:
                         self.ui.debug(_(" %s versions differ, resolve\n") % f)
                         # merge executable bits
                         # "if we changed or they changed, change in merge"
                         a, b, c = mfa.get(f, 0), mfw[f], mf2[f]
                         mode = ((a^b) | (a^c)) ^ a
                         merge[f] = (m1.get(f, nullid), m2[f], mode)
                         s = 1
                     # are we clobbering?
                     # is remote's version newer?
                     # or are we going back in time?
                     elif force or m2[f] != a or (p2 == pa and mw[f] == m1[f]):
                         self.ui.debug(_(" remote %s is newer, get\n") % f)
                         get[f] = m2[f]
                         s = 1
                 elif f in umap:
                     # this unknown file is the same as the checkout
                     get[f] = m2[f]
 
                 if not s and mfw[f] != mf2[f]:
                     if force:
                         self.ui.debug(_(" updating permissions for %s\n") % f)
                         util.set_exec(self.wjoin(f), mf2[f])
                     else:
                         a, b, c = mfa.get(f, 0), mfw[f], mf2[f]
                         mode = ((a^b) | (a^c)) ^ a
                         if mode != b:
                             self.ui.debug(_(" updating permissions for %s\n")
                                           % f)
                             util.set_exec(self.wjoin(f), mode)
                 del m2[f]
             elif f in ma:
                 if n != ma[f]:
                     r = _("d")
                     if not force and (linear_path or allow):
                         r = self.ui.prompt(
                             (_(" local changed %s which remote deleted\n") % f) +
                              _("(k)eep or (d)elete?"), _("[kd]"), _("k"))
                     if r == _("d"):
                         remove.append(f)
                 else:
                     self.ui.debug(_("other deleted %s\n") % f)
                     remove.append(f) # other deleted it
             else:
                 # file is created on branch or in working directory
                 if force and f not in umap:
                     self.ui.debug(_("remote deleted %s, clobbering\n") % f)
                     remove.append(f)
                 elif n == m1.get(f, nullid): # same as parent
                     if p2 == pa: # going backwards?
                         self.ui.debug(_("remote deleted %s\n") % f)
                         remove.append(f)
                     else:
                         self.ui.debug(_("local modified %s, keeping\n") % f)
                 else:
                     self.ui.debug(_("working dir created %s, keeping\n") % f)
 
         for f, n in m2.iteritems():
             if choose and not choose(f):
                 continue
             if f[0] == "/":
                 continue
             if f in ma and n != ma[f]:
                 r = _("k")
                 if not force and (linear_path or allow):
                     r = self.ui.prompt(
                         (_("remote changed %s which local deleted\n") % f) +
                          _("(k)eep or (d)elete?"), _("[kd]"), _("k"))
                 if r == _("k"):
                     get[f] = n
             elif f not in ma:
                 self.ui.debug(_("remote created %s\n") % f)
                 get[f] = n
             else:
                 if force or p2 == pa: # going backwards?
                     self.ui.debug(_("local deleted %s, recreating\n") % f)
                     get[f] = n
                 else:
                     self.ui.debug(_("local deleted %s\n") % f)
 
         del mw, m1, m2, ma
 
         if force:
             for f in merge:
                 get[f] = merge[f][1]
             merge = {}
 
         if linear_path or force:
             # we don't need to do any magic, just jump to the new rev
             branch_merge = False
             p1, p2 = p2, nullid
         else:
             if not allow:
                 self.ui.status(_("this update spans a branch"
                                  " affecting the following files:\n"))
                 fl = merge.keys() + get.keys()
                 fl.sort()
                 for f in fl:
                     cf = ""
                     if f in merge:
                         cf = _(" (resolve)")
                     self.ui.status(" %s%s\n" % (f, cf))
                 self.ui.warn(_("aborting update spanning branches!\n"))
                 self.ui.status(_("(use update -m to merge across branches"
                                  " or -C to lose changes)\n"))
                 return 1
             branch_merge = True
 
         # get the files we don't need to change
         files = get.keys()
         files.sort()
         for f in files:
             if f[0] == "/":
                 continue
             self.ui.note(_("getting %s\n") % f)
             t = self.file(f).read(get[f])
             self.wwrite(f, t)
             util.set_exec(self.wjoin(f), mf2[f])
             if moddirstate:
                 if branch_merge:
                     self.dirstate.update([f], 'n', st_mtime=-1)
                 else:
                     self.dirstate.update([f], 'n')
 
         # merge the tricky bits
         failedmerge = []
         files = merge.keys()
         files.sort()
         xp1 = hex(p1)
         xp2 = hex(p2)
         for f in files:
             self.ui.status(_("merging %s\n") % f)
             my, other, flag = merge[f]
             ret = self.merge3(f, my, other, xp1, xp2)
             if ret:
                 err = True
                 failedmerge.append(f)
             util.set_exec(self.wjoin(f), flag)
             if moddirstate:
                 if branch_merge:
                     # We've done a branch merge, mark this file as merged
                     # so that we properly record the merger later
                     self.dirstate.update([f], 'm')
                 else:
                     # We've update-merged a locally modified file, so
                     # we set the dirstate to emulate a normal checkout
                     # of that file some time in the past. Thus our
                     # merge will appear as a normal local file
                     # modification.
                     f_len = len(self.file(f).read(other))
                     self.dirstate.update([f], 'n', st_size=f_len, st_mtime=-1)
 
         remove.sort()
         for f in remove:
             self.ui.note(_("removing %s\n") % f)
             util.audit_path(f)
             try:
                 util.unlink(self.wjoin(f))
             except OSError, inst:
                 if inst.errno != errno.ENOENT:
                     self.ui.warn(_("update failed to remove %s: %s!\n") %
                                  (f, inst.strerror))
         if moddirstate:
             if branch_merge:
                 self.dirstate.update(remove, 'r')
             else:
                 self.dirstate.forget(remove)
 
         if moddirstate:
             self.dirstate.setparents(p1, p2)
 
         stat = ((len(get), _("updated")),
                 (len(merge) - len(failedmerge), _("merged")),
                 (len(remove), _("removed")),
                 (len(failedmerge), _("unresolved")))
         note = ", ".join([_("%d files %s") % s for s in stat])
         self.ui.note("%s\n" % note)
         if moddirstate and branch_merge:
             self.ui.note(_("(branch merge, don't forget to commit)\n"))
 
         return err
 
     def merge3(self, fn, my, other, p1, p2):
         """perform a 3-way merge in the working directory"""
 
         def temp(prefix, node):
             pre = "%s~%s." % (os.path.basename(fn), prefix)
             (fd, name) = tempfile.mkstemp("", pre)
             f = os.fdopen(fd, "wb")
             self.wwrite(fn, fl.read(node), f)
             f.close()
             return name
 
         fl = self.file(fn)
         base = fl.ancestor(my, other)
         a = self.wjoin(fn)
         b = temp("base", base)
         c = temp("other", other)
 
         self.ui.note(_("resolving %s\n") % fn)
         self.ui.debug(_("file %s: my %s other %s ancestor %s\n") %
                               (fn, short(my), short(other), short(base)))
 
         cmd = (os.environ.get("HGMERGE") or self.ui.config("ui", "merge")
                or "hgmerge")
         r = util.system('%s "%s" "%s" "%s"' % (cmd, a, b, c), cwd=self.root,
                         environ={'HG_FILE': fn,
                                  'HG_MY_NODE': p1,
                                  'HG_OTHER_NODE': p2,
                                  'HG_FILE_MY_NODE': hex(my),
                                  'HG_FILE_OTHER_NODE': hex(other),
                                  'HG_FILE_BASE_NODE': hex(base)})
         if r:
             self.ui.warn(_("merging %s failed!\n") % fn)
 
         os.unlink(b)
         os.unlink(c)
         return r
 
     def verify(self):
         filelinkrevs = {}
         filenodes = {}
         changesets = revisions = files = 0
         errors = [0]
         neededmanifests = {}
 
         def err(msg):
             self.ui.warn(msg + "\n")
             errors[0] += 1
 
         def checksize(obj, name):
             d = obj.checksize()
             if d[0]:
                 err(_("%s data length off by %d bytes") % (name, d[0]))
             if d[1]:
                 err(_("%s index contains %d extra bytes") % (name, d[1]))
 
         seen = {}
         self.ui.status(_("checking changesets\n"))
         checksize(self.changelog, "changelog")
 
         for i in range(self.changelog.count()):
             changesets += 1
             n = self.changelog.node(i)
             l = self.changelog.linkrev(n)
             if l != i:
                 err(_("incorrect link (%d) for changeset revision %d") %(l, i))
             if n in seen:
                 err(_("duplicate changeset at revision %d") % i)
             seen[n] = 1
 
             for p in self.changelog.parents(n):
                 if p not in self.changelog.nodemap:
                     err(_("changeset %s has unknown parent %s") %
                                  (short(n), short(p)))
             try:
                 changes = self.changelog.read(n)
             except KeyboardInterrupt:
                 self.ui.warn(_("interrupted"))
                 raise
             except Exception, inst:
                 err(_("unpacking changeset %s: %s") % (short(n), inst))
                 continue
 
             neededmanifests[changes[0]] = n
 
             for f in changes[3]:
                 filelinkrevs.setdefault(f, []).append(i)
 
         seen = {}
         self.ui.status(_("checking manifests\n"))
         checksize(self.manifest, "manifest")
 
         for i in range(self.manifest.count()):
             n = self.manifest.node(i)
             l = self.manifest.linkrev(n)
 
             if l < 0 or l >= self.changelog.count():
                 err(_("bad manifest link (%d) at revision %d") % (l, i))
 
             if n in neededmanifests:
                 del neededmanifests[n]
 
             if n in seen:
                 err(_("duplicate manifest at revision %d") % i)
 
             seen[n] = 1
 
             for p in self.manifest.parents(n):
                 if p not in self.manifest.nodemap:
                     err(_("manifest %s has unknown parent %s") %
                         (short(n), short(p)))
 
             try:
                 delta = mdiff.patchtext(self.manifest.delta(n))
             except KeyboardInterrupt:
                 self.ui.warn(_("interrupted"))
                 raise
             except Exception, inst:
                 err(_("unpacking manifest %s: %s") % (short(n), inst))
                 continue
 
             try:
                 ff = [ l.split('\0') for l in delta.splitlines() ]
                 for f, fn in ff:
                     filenodes.setdefault(f, {})[bin(fn[:40])] = 1
             except (ValueError, TypeError), inst:
                 err(_("broken delta in manifest %s: %s") % (short(n), inst))
 
         self.ui.status(_("crosschecking files in changesets and manifests\n"))
 
         for m, c in neededmanifests.items():
             err(_("Changeset %s refers to unknown manifest %s") %
                 (short(m), short(c)))
         del neededmanifests
 
         for f in filenodes:
             if f not in filelinkrevs:
                 err(_("file %s in manifest but not in changesets") % f)
 
         for f in filelinkrevs:
             if f not in filenodes:
                 err(_("file %s in changeset but not in manifest") % f)
 
         self.ui.status(_("checking files\n"))
         ff = filenodes.keys()
         ff.sort()
         for f in ff:
             if f == "/dev/null":
                 continue
             files += 1
             if not f:
                 err(_("file without name in manifest %s") % short(n))
                 continue
             fl = self.file(f)
             checksize(fl, f)
 
             nodes = {nullid: 1}
             seen = {}
             for i in range(fl.count()):
                 revisions += 1
                 n = fl.node(i)
 
                 if n in seen:
                     err(_("%s: duplicate revision %d") % (f, i))
                 if n not in filenodes[f]:
                     err(_("%s: %d:%s not in manifests") % (f, i, short(n)))
                 else:
                     del filenodes[f][n]
 
                 flr = fl.linkrev(n)
                 if flr not in filelinkrevs.get(f, []):
                     err(_("%s:%s points to unexpected changeset %d")
                             % (f, short(n), flr))
                 else:
                     filelinkrevs[f].remove(flr)
 
                 # verify contents
                 try:
                     t = fl.read(n)
                 except KeyboardInterrupt:
                     self.ui.warn(_("interrupted"))
                     raise
                 except Exception, inst:
                     err(_("unpacking file %s %s: %s") % (f, short(n), inst))
 
                 # verify parents
                 (p1, p2) = fl.parents(n)
                 if p1 not in nodes:
                     err(_("file %s:%s unknown parent 1 %s") %
                         (f, short(n), short(p1)))
                 if p2 not in nodes:
                     err(_("file %s:%s unknown parent 2 %s") %
                             (f, short(n), short(p1)))
                 nodes[n] = 1
 
             # cross-check
             for node in filenodes[f]:
                 err(_("node %s in manifests not in %s") % (hex(node), f))
 
         self.ui.status(_("%d files, %d changesets, %d total revisions\n") %
                        (files, changesets, revisions))
 
         if errors[0]:
             self.ui.warn(_("%d integrity errors encountered!\n") % errors[0])
             return 1
 
 # used to avoid circular references so destructors work
 def aftertrans(base):
     p = base
     def a():
         util.rename(os.path.join(p, "journal"), os.path.join(p, "undo"))
         util.rename(os.path.join(p, "journal.dirstate"),
                     os.path.join(p, "undo.dirstate"))
     return a
 

mercurial/revlog.py

@@ -1,883 +1,881 b''
 """
 revlog.py - storage back-end for mercurial
 
 This provides efficient delta storage with O(1) retrieve and append
 and O(changes) merge between branches
 
 Copyright 2005 Matt Mackall <[e-mail]>
 
 This software may be used and distributed according to the terms
 of the GNU General Public License, incorporated herein by reference.
 """
 
 from node import *
 from i18n import gettext as _
 from demandload import demandload
-demandload(globals(), "binascii errno heapq mdiff os sha struct zlib")
+demandload(globals(), "binascii changegroup errno heapq mdiff os")
+demandload(globals(), "sha struct zlib")
 
 def hash(text, p1, p2):
     """generate a hash from the given text and its parent hashes
 
     This hash combines both the current file contents and its history
     in a manner that makes it easy to distinguish nodes with the same
     content in the revision graph.
     """
     l = [p1, p2]
     l.sort()
     s = sha.new(l[0])
     s.update(l[1])
     s.update(text)
     return s.digest()
 
 def compress(text):
     """ generate a possibly-compressed representation of text """
     if not text: return ("", text)
     if len(text) < 44:
         if text[0] == '\0': return ("", text)
         return ('u', text)
     bin = zlib.compress(text)
     if len(bin) > len(text):
         if text[0] == '\0': return ("", text)
         return ('u', text)
     return ("", bin)
 
 def decompress(bin):
     """ decompress the given input """
     if not bin: return bin
     t = bin[0]
     if t == '\0': return bin
     if t == 'x': return zlib.decompress(bin)
     if t == 'u': return bin[1:]
     raise RevlogError(_("unknown compression type %r") % t)
 
 indexformat = ">4l20s20s20s"
 
 class lazyparser(object):
     """
     this class avoids the need to parse the entirety of large indices
 
     By default we parse and load 1000 entries at a time.
 
     If no position is specified, we load the whole index, and replace
     the lazy objects in revlog with the underlying objects for
     efficiency in cases where we look at most of the nodes.
     """
     def __init__(self, data, revlog):
         self.data = data
         self.s = struct.calcsize(indexformat)
         self.l = len(data)/self.s
         self.index = [None] * self.l
         self.map = {nullid: -1}
         self.all = 0
         self.revlog = revlog
 
     def trunc(self, pos):
         self.l = pos/self.s
 
     def load(self, pos=None):
         if self.all: return
         if pos is not None:
             block = pos / 1000
             i = block * 1000
             end = min(self.l, i + 1000)
         else:
             self.all = 1
             i = 0
             end = self.l
             self.revlog.index = self.index
             self.revlog.nodemap = self.map
 
         while i < end:
             d = self.data[i * self.s: (i + 1) * self.s]
             e = struct.unpack(indexformat, d)
             self.index[i] = e
             self.map[e[6]] = i
             i += 1
 
 class lazyindex(object):
     """a lazy version of the index array"""
     def __init__(self, parser):
         self.p = parser
     def __len__(self):
         return len(self.p.index)
     def load(self, pos):
         if pos < 0:
             pos += len(self.p.index)
         self.p.load(pos)
         return self.p.index[pos]
     def __getitem__(self, pos):
         return self.p.index[pos] or self.load(pos)
     def __delitem__(self, pos):
         del self.p.index[pos]
     def append(self, e):
         self.p.index.append(e)
     def trunc(self, pos):
         self.p.trunc(pos)
 
 class lazymap(object):
     """a lazy version of the node map"""
     def __init__(self, parser):
         self.p = parser
     def load(self, key):
         if self.p.all: return
         n = self.p.data.find(key)
         if n < 0:
             raise KeyError(key)
         pos = n / self.p.s
         self.p.load(pos)
     def __contains__(self, key):
         self.p.load()
         return key in self.p.map
     def __iter__(self):
         yield nullid
         for i in xrange(self.p.l):
             try:
                 yield self.p.index[i][6]
             except:
                 self.p.load(i)
                 yield self.p.index[i][6]
     def __getitem__(self, key):
         try:
             return self.p.map[key]
         except KeyError:
             try:
                 self.load(key)
                 return self.p.map[key]
             except KeyError:
                 raise KeyError("node " + hex(key))
     def __setitem__(self, key, val):
         self.p.map[key] = val
     def __delitem__(self, key):
         del self.p.map[key]
 
 class RevlogError(Exception): pass
 
 class revlog(object):
     """
     the underlying revision storage object
 
     A revlog consists of two parts, an index and the revision data.
 
     The index is a file with a fixed record size containing
     information on each revision, includings its nodeid (hash), the
     nodeids of its parents, the position and offset of its data within
     the data file, and the revision it's based on. Finally, each entry
     contains a linkrev entry that can serve as a pointer to external
     data.
 
     The revision data itself is a linear collection of data chunks.
     Each chunk represents a revision and is usually represented as a
     delta against the previous chunk. To bound lookup time, runs of
     deltas are limited to about 2 times the length of the original
     version data. This makes retrieval of a version proportional to
     its size, or O(1) relative to the number of revisions.
 
     Both pieces of the revlog are written to in an append-only
     fashion, which means we never need to rewrite a file to insert or
     remove data, and can use some simple techniques to avoid the need
     for locking while reading.
     """
     def __init__(self, opener, indexfile, datafile):
         """
         create a revlog object
 
         opener is a function that abstracts the file opening operation
         and can be used to implement COW semantics or the like.
         """
         self.indexfile = indexfile
         self.datafile = datafile
         self.opener = opener
 
         self.indexstat = None
         self.cache = None
         self.chunkcache = None
         self.load()
 
     def load(self):
         try:
             f = self.opener(self.indexfile)
         except IOError, inst:
             if inst.errno != errno.ENOENT:
                 raise
             i = ""
         else:
             try:
                 st = os.fstat(f.fileno())
             except AttributeError, inst:
                 st = None
             else:
                 oldst = self.indexstat
                 if (oldst and st.st_dev == oldst.st_dev
                     and st.st_ino == oldst.st_ino
                     and st.st_mtime == oldst.st_mtime
                     and st.st_ctime == oldst.st_ctime):
                     return
             self.indexstat = st
             i = f.read()
 
         if i and i[:4] != "\0\0\0\0":
             raise RevlogError(_("incompatible revlog signature on %s") %
                               self.indexfile)
 
         if len(i) > 10000:
             # big index, let's parse it on demand
             parser = lazyparser(i, self)
             self.index = lazyindex(parser)
             self.nodemap = lazymap(parser)
         else:
             s = struct.calcsize(indexformat)
             l = len(i) / s
             self.index = [None] * l
             m = [None] * l
 
             n = 0
             for f in xrange(0, l * s, s):
                 # offset, size, base, linkrev, p1, p2, nodeid
                 e = struct.unpack(indexformat, i[f:f + s])
                 m[n] = (e[6], n)
                 self.index[n] = e
                 n += 1
 
             self.nodemap = dict(m)
             self.nodemap[nullid] = -1
 
     def tip(self): return self.node(len(self.index) - 1)
     def count(self): return len(self.index)
     def node(self, rev): return (rev < 0) and nullid or self.index[rev][6]
     def rev(self, node):
         try:
             return self.nodemap[node]
         except KeyError:
             raise RevlogError(_('%s: no node %s') % (self.indexfile, hex(node)))
     def linkrev(self, node): return self.index[self.rev(node)][3]
     def parents(self, node):
         if node == nullid: return (nullid, nullid)
         return self.index[self.rev(node)][4:6]
 
     def start(self, rev): return (rev < 0) and -1 or self.index[rev][0]
     def length(self, rev):
         if rev < 0:
             return 0
         else:
             return self.index[rev][1]
     def end(self, rev): return self.start(rev) + self.length(rev)
     def base(self, rev): return (rev < 0) and rev or self.index[rev][2]
 
     def reachable(self, rev, stop=None):
         reachable = {}
         visit = [rev]
         reachable[rev] = 1
         if stop:
             stopn = self.rev(stop)
         else:
             stopn = 0
         while visit:
             n = visit.pop(0)
             if n == stop:
                 continue
             if n == nullid:
                 continue
             for p in self.parents(n):
                 if self.rev(p) < stopn:
                     continue
                 if p not in reachable:
                     reachable[p] = 1
                     visit.append(p)
         return reachable
 
     def nodesbetween(self, roots=None, heads=None):
         """Return a tuple containing three elements. Elements 1 and 2 contain
         a final list bases and heads after all the unreachable ones have been
         pruned.  Element 0 contains a topologically sorted list of all
 
         nodes that satisfy these constraints:
         1. All nodes must be descended from a node in roots (the nodes on
            roots are considered descended from themselves).
         2. All nodes must also be ancestors of a node in heads (the nodes in
            heads are considered to be their own ancestors).
 
         If roots is unspecified, nullid is assumed as the only root.
         If heads is unspecified, it is taken to be the output of the
         heads method (i.e. a list of all nodes in the repository that
         have no children)."""
         nonodes = ([], [], [])
         if roots is not None:
             roots = list(roots)
             if not roots:
                 return nonodes
             lowestrev = min([self.rev(n) for n in roots])
         else:
             roots = [nullid] # Everybody's a descendent of nullid
             lowestrev = -1
         if (lowestrev == -1) and (heads is None):
             # We want _all_ the nodes!
             return ([self.node(r) for r in xrange(0, self.count())],
                     [nullid], list(self.heads()))
         if heads is None:
             # All nodes are ancestors, so the latest ancestor is the last
             # node.
             highestrev = self.count() - 1
             # Set ancestors to None to signal that every node is an ancestor.
             ancestors = None
             # Set heads to an empty dictionary for later discovery of heads
             heads = {}
         else:
             heads = list(heads)
             if not heads:
                 return nonodes
             ancestors = {}
             # Start at the top and keep marking parents until we're done.
             nodestotag = heads[:]
             # Turn heads into a dictionary so we can remove 'fake' heads.
             # Also, later we will be using it to filter out the heads we can't
             # find from roots.
             heads = dict.fromkeys(heads, 0)
             # Remember where the top was so we can use it as a limit later.
             highestrev = max([self.rev(n) for n in nodestotag])
             while nodestotag:
                 # grab a node to tag
                 n = nodestotag.pop()
                 # Never tag nullid
                 if n == nullid:
                     continue
                 # A node's revision number represents its place in a
                 # topologically sorted list of nodes.
                 r = self.rev(n)
                 if r >= lowestrev:
                     if n not in ancestors:
                         # If we are possibly a descendent of one of the roots
                         # and we haven't already been marked as an ancestor
                         ancestors[n] = 1 # Mark as ancestor
                         # Add non-nullid parents to list of nodes to tag.
                         nodestotag.extend([p for p in self.parents(n) if
                                            p != nullid])
                     elif n in heads: # We've seen it before, is it a fake head?
                         # So it is, real heads should not be the ancestors of
                         # any other heads.
                         heads.pop(n)
             if not ancestors:
                 return nonodes
             # Now that we have our set of ancestors, we want to remove any
             # roots that are not ancestors.
 
             # If one of the roots was nullid, everything is included anyway.
             if lowestrev > -1:
                 # But, since we weren't, let's recompute the lowest rev to not
                 # include roots that aren't ancestors.
 
                 # Filter out roots that aren't ancestors of heads
                 roots = [n for n in roots if n in ancestors]
                 # Recompute the lowest revision
                 if roots:
                     lowestrev = min([self.rev(n) for n in roots])
                 else:
                     # No more roots?  Return empty list
                     return nonodes
             else:
                 # We are descending from nullid, and don't need to care about
                 # any other roots.
                 lowestrev = -1
                 roots = [nullid]
         # Transform our roots list into a 'set' (i.e. a dictionary where the
         # values don't matter.
         descendents = dict.fromkeys(roots, 1)
         # Also, keep the original roots so we can filter out roots that aren't
         # 'real' roots (i.e. are descended from other roots).
         roots = descendents.copy()
         # Our topologically sorted list of output nodes.
         orderedout = []
         # Don't start at nullid since we don't want nullid in our output list,
         # and if nullid shows up in descedents, empty parents will look like
         # they're descendents.
         for r in xrange(max(lowestrev, 0), highestrev + 1):
             n = self.node(r)
             isdescendent = False
             if lowestrev == -1:  # Everybody is a descendent of nullid
                 isdescendent = True
             elif n in descendents:
                 # n is already a descendent
                 isdescendent = True
                 # This check only needs to be done here because all the roots
                 # will start being marked is descendents before the loop.
                 if n in roots:
                     # If n was a root, check if it's a 'real' root.
                     p = tuple(self.parents(n))
                     # If any of its parents are descendents, it's not a root.
                     if (p[0] in descendents) or (p[1] in descendents):
                         roots.pop(n)
             else:
                 p = tuple(self.parents(n))
                 # A node is a descendent if either of its parents are
                 # descendents.  (We seeded the dependents list with the roots
                 # up there, remember?)
                 if (p[0] in descendents) or (p[1] in descendents):
                     descendents[n] = 1
                     isdescendent = True
             if isdescendent and ((ancestors is None) or (n in ancestors)):
                 # Only include nodes that are both descendents and ancestors.
                 orderedout.append(n)
                 if (ancestors is not None) and (n in heads):
                     # We're trying to figure out which heads are reachable
                     # from roots.
                     # Mark this head as having been reached
                     heads[n] = 1
                 elif ancestors is None:
                     # Otherwise, we're trying to discover the heads.
                     # Assume this is a head because if it isn't, the next step
                     # will eventually remove it.
                     heads[n] = 1
                     # But, obviously its parents aren't.
                     for p in self.parents(n):
                         heads.pop(p, None)
         heads = [n for n in heads.iterkeys() if heads[n] != 0]
         roots = roots.keys()
         assert orderedout
         assert roots
         assert heads
         return (orderedout, roots, heads)
 
     def heads(self, start=None):
         """return the list of all nodes that have no children
 
         if start is specified, only heads that are descendants of
         start will be returned
 
         """
         if start is None:
             start = nullid
         reachable = {start: 1}
         heads = {start: 1}
         startrev = self.rev(start)
 
         for r in xrange(startrev + 1, self.count()):
             n = self.node(r)
             for pn in self.parents(n):
                 if pn in reachable:
                     reachable[n] = 1
                     heads[n] = 1
                 if pn in heads:
                     del heads[pn]
         return heads.keys()
 
     def children(self, node):
         """find the children of a given node"""
         c = []
         p = self.rev(node)
         for r in range(p + 1, self.count()):
             n = self.node(r)
             for pn in self.parents(n):
                 if pn == node:
                     c.append(n)
                     continue
                 elif pn == nullid:
                     continue
         return c
 
     def lookup(self, id):
         """locate a node based on revision number or subset of hex nodeid"""
         try:
             rev = int(id)
             if str(rev) != id: raise ValueError
             if rev < 0: rev = self.count() + rev
             if rev < 0 or rev >= self.count(): raise ValueError
             return self.node(rev)
         except (ValueError, OverflowError):
             c = []
             for n in self.nodemap:
                 if hex(n).startswith(id):
                     c.append(n)
             if len(c) > 1: raise RevlogError(_("Ambiguous identifier"))
             if len(c) < 1: raise RevlogError(_("No match found"))
             return c[0]
 
         return None
 
     def diff(self, a, b):
         """return a delta between two revisions"""
         return mdiff.textdiff(a, b)
 
     def patches(self, t, pl):
         """apply a list of patches to a string"""
         return mdiff.patches(t, pl)
 
     def chunk(self, rev):
         start, length = self.start(rev), self.length(rev)
         end = start + length
 
         def loadcache():
             cache_length = max(4096 * 1024, length) # 4Mo
             df = self.opener(self.datafile)
             df.seek(start)
             self.chunkcache = (start, df.read(cache_length))
 
         if not self.chunkcache:
             loadcache()
 
         cache_start = self.chunkcache[0]
         cache_end = cache_start + len(self.chunkcache[1])
         if start >= cache_start and end <= cache_end:
             # it is cached
             offset = start - cache_start
         else:
             loadcache()
             offset = 0
 
         #def checkchunk():
         #    df = self.opener(self.datafile)
         #    df.seek(start)
         #    return df.read(length)
         #assert s == checkchunk()
         return decompress(self.chunkcache[1][offset:offset + length])
 
     def delta(self, node):
         """return or calculate a delta between a node and its predecessor"""
         r = self.rev(node)
         return self.revdiff(r - 1, r)
 
     def revdiff(self, rev1, rev2):
         """return or calculate a delta between two revisions"""
         b1 = self.base(rev1)
         b2 = self.base(rev2)
         if b1 == b2 and rev1 + 1 == rev2:
             return self.chunk(rev2)
         else:
             return self.diff(self.revision(self.node(rev1)),
                              self.revision(self.node(rev2)))
 
     def revision(self, node):
         """return an uncompressed revision of a given"""
         if node == nullid: return ""
         if self.cache and self.cache[0] == node: return self.cache[2]
 
         # look up what we need to read
         text = None
         rev = self.rev(node)
         base = self.base(rev)
 
         # do we have useful data cached?
         if self.cache and self.cache[1] >= base and self.cache[1] < rev:
             base = self.cache[1]
             text = self.cache[2]
         else:
             text = self.chunk(base)
 
         bins = []
         for r in xrange(base + 1, rev + 1):
             bins.append(self.chunk(r))
 
         text = self.patches(text, bins)
 
         p1, p2 = self.parents(node)
         if node != hash(text, p1, p2):
             raise RevlogError(_("integrity check failed on %s:%d")
                           % (self.datafile, rev))
 
         self.cache = (node, rev, text)
         return text
 
     def addrevision(self, text, transaction, link, p1=None, p2=None, d=None):
         """add a revision to the log
 
         text - the revision data to add
         transaction - the transaction object used for rollback
         link - the linkrev data to add
         p1, p2 - the parent nodeids of the revision
         d - an optional precomputed delta
         """
         if text is None: text = ""
         if p1 is None: p1 = self.tip()
         if p2 is None: p2 = nullid
 
         node = hash(text, p1, p2)
 
         if node in self.nodemap:
             return node
 
         n = self.count()
         t = n - 1
 
         if n:
             base = self.base(t)
             start = self.start(base)
             end = self.end(t)
             if not d:
                 prev = self.revision(self.tip())
                 d = self.diff(prev, str(text))
             data = compress(d)
             l = len(data[1]) + len(data[0])
             dist = end - start + l
 
         # full versions are inserted when the needed deltas
         # become comparable to the uncompressed text
         if not n or dist > len(text) * 2:
             data = compress(text)
             l = len(data[1]) + len(data[0])
             base = n
         else:
             base = self.base(t)
 
         offset = 0
         if t >= 0:
             offset = self.end(t)
 
         e = (offset, l, base, link, p1, p2, node)
 
         self.index.append(e)
         self.nodemap[node] = n
         entry = struct.pack(indexformat, *e)
 
         transaction.add(self.datafile, e[0])
         f = self.opener(self.datafile, "a")
         if data[0]:
             f.write(data[0])
         f.write(data[1])
         transaction.add(self.indexfile, n * len(entry))
         self.opener(self.indexfile, "a").write(entry)
 
         self.cache = (node, n, text)
         return node
 
     def ancestor(self, a, b):
         """calculate the least common ancestor of nodes a and b"""
         # calculate the distance of every node from root
         dist = {nullid: 0}
         for i in xrange(self.count()):
             n = self.node(i)
             p1, p2 = self.parents(n)
             dist[n] = max(dist[p1], dist[p2]) + 1
 
         # traverse ancestors in order of decreasing distance from root
         def ancestors(node):
             # we store negative distances because heap returns smallest member
             h = [(-dist[node], node)]
             seen = {}
             while h:
                 d, n = heapq.heappop(h)
                 if n not in seen:
                     seen[n] = 1
                     yield (-d, n)
                     for p in self.parents(n):
                         heapq.heappush(h, (-dist[p], p))
 
         def generations(node):
             sg, s = None, {}
             for g,n in ancestors(node):
                 if g != sg:
                     if sg:
                         yield sg, s
                     sg, s = g, {n:1}
                 else:
                     s[n] = 1
             yield sg, s
 
         x = generations(a)
         y = generations(b)
         gx = x.next()
         gy = y.next()
 
         # increment each ancestor list until it is closer to root than
         # the other, or they match
         while 1:
             #print "ancestor gen %s %s" % (gx[0], gy[0])
             if gx[0] == gy[0]:
                 # find the intersection
                 i = [ n for n in gx[1] if n in gy[1] ]
                 if i:
                     return i[0]
                 else:
                     #print "next"
                     gy = y.next()
                     gx = x.next()
             elif gx[0] < gy[0]:
                 #print "next y"
                 gy = y.next()
             else:
                 #print "next x"
                 gx = x.next()
 
     def group(self, nodelist, lookup, infocollect=None):
         """calculate a delta group
 
         Given a list of changeset revs, return a set of deltas and
         metadata corresponding to nodes. the first delta is
         parent(nodes[0]) -> nodes[0] the receiver is guaranteed to
         have this parent as it has all history before these
         changesets. parent is parent[0]
         """
         revs = [self.rev(n) for n in nodelist]
 
         # if we don't have any revisions touched by these changesets, bail
         if not revs:
-            yield struct.pack(">l", 0)
+            yield changegroup.closechunk()
             return
 
         # add the parent of the first rev
         p = self.parents(self.node(revs[0]))[0]
         revs.insert(0, self.rev(p))
 
         # build deltas
         for d in xrange(0, len(revs) - 1):
             a, b = revs[d], revs[d + 1]
             nb = self.node(b)
 
             if infocollect is not None:
                 infocollect(nb)
 
             d = self.revdiff(a, b)
             p = self.parents(nb)
             meta = nb + p[0] + p[1] + lookup(nb)
-            l = struct.pack(">l", len(meta) + len(d) + 4)
-            yield l
-            yield meta
-            yield d
+            yield changegroup.genchunk("%s%s" % (meta, d))
 
-        yield struct.pack(">l", 0)
+        yield changegroup.closechunk()
 
     def addgroup(self, revs, linkmapper, transaction, unique=0):
         """
         add a delta group
 
         given a set of deltas, add them to the revision log. the
         first delta is against its parent, which should be in our
         log, the rest are against the previous delta.
         """
 
         #track the base of the current delta log
         r = self.count()
         t = r - 1
         node = nullid
 
         base = prev = -1
         start = end = measure = 0
         if r:
             base = self.base(t)
             start = self.start(base)
             end = self.end(t)
             measure = self.length(base)
             prev = self.tip()
 
         transaction.add(self.datafile, end)
         transaction.add(self.indexfile, r * struct.calcsize(indexformat))
         dfh = self.opener(self.datafile, "a")
         ifh = self.opener(self.indexfile, "a")
 
         # loop through our set of deltas
         chain = None
         for chunk in revs:
             node, p1, p2, cs = struct.unpack("20s20s20s20s", chunk[:80])
             link = linkmapper(cs)
             if node in self.nodemap:
                 # this can happen if two branches make the same change
                 # if unique:
                 #    raise RevlogError(_("already have %s") % hex(node[:4]))
                 chain = node
                 continue
             delta = chunk[80:]
 
             for p in (p1, p2):
                 if not p in self.nodemap:
                     raise RevlogError(_("unknown parent %s") % short(p1))
 
             if not chain:
                 # retrieve the parent revision of the delta chain
                 chain = p1
                 if not chain in self.nodemap:
                     raise RevlogError(_("unknown base %s") % short(chain[:4]))
 
             # full versions are inserted when the needed deltas become
             # comparable to the uncompressed text or when the previous
             # version is not the one we have a delta against. We use
             # the size of the previous full rev as a proxy for the
             # current size.
 
             if chain == prev:
                 tempd = compress(delta)
                 cdelta = tempd[0] + tempd[1]
 
             if chain != prev or (end - start + len(cdelta)) > measure * 2:
                 # flush our writes here so we can read it in revision
                 dfh.flush()
                 ifh.flush()
                 text = self.revision(chain)
                 text = self.patches(text, [delta])
                 chk = self.addrevision(text, transaction, link, p1, p2)
                 if chk != node:
                     raise RevlogError(_("consistency error adding group"))
                 measure = len(text)
             else:
                 e = (end, len(cdelta), base, link, p1, p2, node)
                 self.index.append(e)
                 self.nodemap[node] = r
                 dfh.write(cdelta)
                 ifh.write(struct.pack(indexformat, *e))
 
             t, r, chain, prev = r, r + 1, node, node
             base = self.base(t)
             start = self.start(base)
             end = self.end(t)
 
         dfh.close()
         ifh.close()
         return node
 
     def strip(self, rev, minlink):
         if self.count() == 0 or rev >= self.count():
             return
 
         # When stripping away a revision, we need to make sure it
         # does not actually belong to an older changeset.
         # The minlink parameter defines the oldest revision
         # we're allowed to strip away.
         while minlink > self.index[rev][3]:
             rev += 1
             if rev >= self.count():
                 return
 
         # first truncate the files on disk
         end = self.start(rev)
         self.opener(self.datafile, "a").truncate(end)
         end = rev * struct.calcsize(indexformat)
         self.opener(self.indexfile, "a").truncate(end)
 
         # then reset internal state in memory to forget those revisions
         self.cache = None
         self.chunkcache = None
         for p in self.index[rev:]:
             del self.nodemap[p[6]]
         del self.index[rev:]
 
         # truncating the lazyindex also truncates the lazymap.
         if isinstance(self.index, lazyindex):
             self.index.trunc(end)
 
 
     def checksize(self):
         expected = 0
         if self.count():
             expected = self.end(self.count() - 1)
 
         try:
             f = self.opener(self.datafile)
             f.seek(0, 2)
             actual = f.tell()
             dd = actual - expected
         except IOError, inst:
             if inst.errno != errno.ENOENT:
                 raise
             dd = 0
 
         try:
             f = self.opener(self.indexfile)
             f.seek(0, 2)
             actual = f.tell()
             s = struct.calcsize(indexformat)
             i = actual / s
             di = actual - (i * s)
         except IOError, inst:
             if inst.errno != errno.ENOENT:
                 raise
             di = 0
 
         return (dd, di)