--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/eggs/mercurial-1.7.3-py2.6-linux-x86_64.egg/mercurial/tags.py Sat Jan 08 11:20:57 2011 +0530
@@ -0,0 +1,288 @@
+# tags.py - read tag info from local repository
+#
+# Copyright 2009 Matt Mackall <mpm@selenic.com>
+# Copyright 2009 Greg Ward <greg@gerg.ca>
+#
+# This software may be used and distributed according to the terms of the
+# GNU General Public License version 2 or any later version.
+
+# Currently this module only deals with reading and caching tags.
+# Eventually, it could take care of updating (adding/removing/moving)
+# tags too.
+
+from node import nullid, bin, hex, short
+from i18n import _
+import encoding
+import error
+
+def findglobaltags(ui, repo, alltags, tagtypes):
+ '''Find global tags in repo by reading .hgtags from every head that
+ has a distinct version of it, using a cache to avoid excess work.
+ Updates the dicts alltags, tagtypes in place: alltags maps tag name
+ to (node, hist) pair (see _readtags() below), and tagtypes maps tag
+ name to tag type ("global" in this case).'''
+ # This is so we can be lazy and assume alltags contains only global
+ # tags when we pass it to _writetagcache().
+ assert len(alltags) == len(tagtypes) == 0, \
+ "findglobaltags() should be called first"
+
+ (heads, tagfnode, cachetags, shouldwrite) = _readtagcache(ui, repo)
+ if cachetags is not None:
+ assert not shouldwrite
+ # XXX is this really 100% correct? are there oddball special
+ # cases where a global tag should outrank a local tag but won't,
+ # because cachetags does not contain rank info?
+ _updatetags(cachetags, 'global', alltags, tagtypes)
+ return
+
+ seen = set() # set of fnode
+ fctx = None
+ for head in reversed(heads): # oldest to newest
+ assert head in repo.changelog.nodemap, \
+ "tag cache returned bogus head %s" % short(head)
+
+ fnode = tagfnode.get(head)
+ if fnode and fnode not in seen:
+ seen.add(fnode)
+ if not fctx:
+ fctx = repo.filectx('.hgtags', fileid=fnode)
+ else:
+ fctx = fctx.filectx(fnode)
+
+ filetags = _readtags(ui, repo, fctx.data().splitlines(), fctx)
+ _updatetags(filetags, 'global', alltags, tagtypes)
+
+ # and update the cache (if necessary)
+ if shouldwrite:
+ _writetagcache(ui, repo, heads, tagfnode, alltags)
+
+def readlocaltags(ui, repo, alltags, tagtypes):
+ '''Read local tags in repo. Update alltags and tagtypes.'''
+ try:
+ # localtags is in the local encoding; re-encode to UTF-8 on
+ # input for consistency with the rest of this module.
+ data = repo.opener("localtags").read()
+ filetags = _readtags(
+ ui, repo, data.splitlines(), "localtags",
+ recode=encoding.fromlocal)
+ _updatetags(filetags, "local", alltags, tagtypes)
+ except IOError:
+ pass
+
+def _readtags(ui, repo, lines, fn, recode=None):
+ '''Read tag definitions from a file (or any source of lines).
+ Return a mapping from tag name to (node, hist): node is the node id
+ from the last line read for that name, and hist is the list of node
+ ids previously associated with it (in file order). All node ids are
+ binary, not hex.'''
+
+ filetags = {} # map tag name to (node, hist)
+ count = 0
+
+ def warn(msg):
+ ui.warn(_("%s, line %s: %s\n") % (fn, count, msg))
+
+ for line in lines:
+ count += 1
+ if not line:
+ continue
+ try:
+ (nodehex, name) = line.split(" ", 1)
+ except ValueError:
+ warn(_("cannot parse entry"))
+ continue
+ name = name.strip()
+ if recode:
+ name = recode(name)
+ try:
+ nodebin = bin(nodehex)
+ except TypeError:
+ warn(_("node '%s' is not well formed") % nodehex)
+ continue
+ if nodebin not in repo.changelog.nodemap:
+ # silently ignore as pull -r might cause this
+ continue
+
+ # update filetags
+ hist = []
+ if name in filetags:
+ n, hist = filetags[name]
+ hist.append(n)
+ filetags[name] = (nodebin, hist)
+ return filetags
+
+def _updatetags(filetags, tagtype, alltags, tagtypes):
+ '''Incorporate the tag info read from one file into the two
+ dictionaries, alltags and tagtypes, that contain all tag
+ info (global across all heads plus local).'''
+
+ for name, nodehist in filetags.iteritems():
+ if name not in alltags:
+ alltags[name] = nodehist
+ tagtypes[name] = tagtype
+ continue
+
+ # we prefer alltags[name] if:
+ # it supercedes us OR
+ # mutual supercedes and it has a higher rank
+ # otherwise we win because we're tip-most
+ anode, ahist = nodehist
+ bnode, bhist = alltags[name]
+ if (bnode != anode and anode in bhist and
+ (bnode not in ahist or len(bhist) > len(ahist))):
+ anode = bnode
+ ahist.extend([n for n in bhist if n not in ahist])
+ alltags[name] = anode, ahist
+ tagtypes[name] = tagtype
+
+
+# The tag cache only stores info about heads, not the tag contents
+# from each head. I.e. it doesn't try to squeeze out the maximum
+# performance, but is simpler has a better chance of actually
+# working correctly. And this gives the biggest performance win: it
+# avoids looking up .hgtags in the manifest for every head, and it
+# can avoid calling heads() at all if there have been no changes to
+# the repo.
+
+def _readtagcache(ui, repo):
+ '''Read the tag cache and return a tuple (heads, fnodes, cachetags,
+ shouldwrite). If the cache is completely up-to-date, cachetags is a
+ dict of the form returned by _readtags(); otherwise, it is None and
+ heads and fnodes are set. In that case, heads is the list of all
+ heads currently in the repository (ordered from tip to oldest) and
+ fnodes is a mapping from head to .hgtags filenode. If those two are
+ set, caller is responsible for reading tag info from each head.'''
+
+ try:
+ cachefile = repo.opener('tags.cache', 'r')
+ # force reading the file for static-http
+ cachelines = iter(cachefile)
+ except IOError:
+ cachefile = None
+
+ # The cache file consists of lines like
+ # <headrev> <headnode> [<tagnode>]
+ # where <headrev> and <headnode> redundantly identify a repository
+ # head from the time the cache was written, and <tagnode> is the
+ # filenode of .hgtags on that head. Heads with no .hgtags file will
+ # have no <tagnode>. The cache is ordered from tip to oldest (which
+ # is part of why <headrev> is there: a quick visual check is all
+ # that's required to ensure correct order).
+ #
+ # This information is enough to let us avoid the most expensive part
+ # of finding global tags, which is looking up <tagnode> in the
+ # manifest for each head.
+ cacherevs = [] # list of headrev
+ cacheheads = [] # list of headnode
+ cachefnode = {} # map headnode to filenode
+ if cachefile:
+ try:
+ for line in cachelines:
+ if line == "\n":
+ break
+ line = line.rstrip().split()
+ cacherevs.append(int(line[0]))
+ headnode = bin(line[1])
+ cacheheads.append(headnode)
+ if len(line) == 3:
+ fnode = bin(line[2])
+ cachefnode[headnode] = fnode
+ except (ValueError, TypeError):
+ # corruption of tags.cache, just recompute it
+ ui.warn(_('.hg/tags.cache is corrupt, rebuilding it\n'))
+ cacheheads = []
+ cacherevs = []
+ cachefnode = {}
+
+ tipnode = repo.changelog.tip()
+ tiprev = len(repo.changelog) - 1
+
+ # Case 1 (common): tip is the same, so nothing has changed.
+ # (Unchanged tip trivially means no changesets have been added.
+ # But, thanks to localrepository.destroyed(), it also means none
+ # have been destroyed by strip or rollback.)
+ if cacheheads and cacheheads[0] == tipnode and cacherevs[0] == tiprev:
+ tags = _readtags(ui, repo, cachelines, cachefile.name)
+ cachefile.close()
+ return (None, None, tags, False)
+ if cachefile:
+ cachefile.close() # ignore rest of file
+
+ repoheads = repo.heads()
+ # Case 2 (uncommon): empty repo; get out quickly and don't bother
+ # writing an empty cache.
+ if repoheads == [nullid]:
+ return ([], {}, {}, False)
+
+ # Case 3 (uncommon): cache file missing or empty.
+
+ # Case 4 (uncommon): tip rev decreased. This should only happen
+ # when we're called from localrepository.destroyed(). Refresh the
+ # cache so future invocations will not see disappeared heads in the
+ # cache.
+
+ # Case 5 (common): tip has changed, so we've added/replaced heads.
+
+ # As it happens, the code to handle cases 3, 4, 5 is the same.
+
+ # N.B. in case 4 (nodes destroyed), "new head" really means "newly
+ # exposed".
+ newheads = [head
+ for head in repoheads
+ if head not in set(cacheheads)]
+
+ # Now we have to lookup the .hgtags filenode for every new head.
+ # This is the most expensive part of finding tags, so performance
+ # depends primarily on the size of newheads. Worst case: no cache
+ # file, so newheads == repoheads.
+ for head in newheads:
+ cctx = repo[head]
+ try:
+ fnode = cctx.filenode('.hgtags')
+ cachefnode[head] = fnode
+ except error.LookupError:
+ # no .hgtags file on this head
+ pass
+
+ # Caller has to iterate over all heads, but can use the filenodes in
+ # cachefnode to get to each .hgtags revision quickly.
+ return (repoheads, cachefnode, None, True)
+
+def _writetagcache(ui, repo, heads, tagfnode, cachetags):
+
+ try:
+ cachefile = repo.opener('tags.cache', 'w', atomictemp=True)
+ except (OSError, IOError):
+ return
+
+ realheads = repo.heads() # for sanity checks below
+ for head in heads:
+ # temporary sanity checks; these can probably be removed
+ # once this code has been in crew for a few weeks
+ assert head in repo.changelog.nodemap, \
+ 'trying to write non-existent node %s to tag cache' % short(head)
+ assert head in realheads, \
+ 'trying to write non-head %s to tag cache' % short(head)
+ assert head != nullid, \
+ 'trying to write nullid to tag cache'
+
+ # This can't fail because of the first assert above. When/if we
+ # remove that assert, we might want to catch LookupError here
+ # and downgrade it to a warning.
+ rev = repo.changelog.rev(head)
+
+ fnode = tagfnode.get(head)
+ if fnode:
+ cachefile.write('%d %s %s\n' % (rev, hex(head), hex(fnode)))
+ else:
+ cachefile.write('%d %s\n' % (rev, hex(head)))
+
+ # Tag names in the cache are in UTF-8 -- which is the whole reason
+ # we keep them in UTF-8 throughout this module. If we converted
+ # them local encoding on input, we would lose info writing them to
+ # the cache.
+ cachefile.write('\n')
+ for (name, (node, hist)) in cachetags.iteritems():
+ cachefile.write("%s %s\n" % (hex(node), name))
+
+ cachefile.rename()