bundlerepo: fix outdated comment

Comment was made invalid by 01ee43dda681.

mercurial/bundlerepo.py

@@ -1,388 +1,389
 # bundlerepo.py - repository class for viewing uncompressed bundles
 #
 # Copyright 2006, 2007 Benoit Boissinot <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 """Repository class for viewing uncompressed bundles.
 
 This provides a read-only repository interface to bundles as if they
 were part of the actual repository.
 """
 
 from node import nullid
 from i18n import _
 import os, tempfile, shutil
 import changegroup, util, mdiff, discovery, cmdutil, scmutil
 import localrepo, changelog, manifest, filelog, revlog, error
 
 class bundlerevlog(revlog.revlog):
     def __init__(self, opener, indexfile, bundle, linkmapper):
         # How it works:
-        # to retrieve a revision, we need to know the offset of
-        # the revision in the bundle (an unbundle object).
+        # To retrieve a revision, we need to know the offset of the revision in
+        # the bundle (an unbundle object). We store this offset in the index
+        # (start).
         #
-        # 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)
+        # basemap is indexed with revisions coming from the bundle, and it
+        # maps to the corresponding node that is the base of the corresponding
+        # delta.
         #
+        # To differentiate a rev in the bundle from a rev in the revlog, we
+        # check revision against basemap.
         opener = scmutil.readonlyvfs(opener)
         revlog.revlog.__init__(self, opener, indexfile)
         self.bundle = bundle
         self.basemap = {}
         n = len(self)
         self.disktiprev = n - 1
         chain = None
         self.bundlenodes = []
         while True:
             chunkdata = bundle.deltachunk(chain)
             if not chunkdata:
                 break
             node = chunkdata['node']
             p1 = chunkdata['p1']
             p2 = chunkdata['p2']
             cs = chunkdata['cs']
             deltabase = chunkdata['deltabase']
             delta = chunkdata['delta']
 
             size = len(delta)
             start = bundle.tell() - size
 
             link = linkmapper(cs)
             self.bundlenodes.append(node)
             if node in self.nodemap:
                 # this can happen if two branches make the same change
                 chain = node
                 continue
 
             for p in (p1, p2):
                 if p not in self.nodemap:
                     raise error.LookupError(p, self.indexfile,
                                             _("unknown parent"))
             # start, size, full unc. size, base (unused), link, p1, p2, node
             e = (revlog.offset_type(start, 0), size, -1, -1, link,
                  self.rev(p1), self.rev(p2), node)
             self.basemap[n] = deltabase
             self.index.insert(-1, e)
             self.nodemap[node] = n
             chain = node
             n += 1
 
     def inbundle(self, rev):
         """is rev from the bundle"""
         if rev < 0:
             return False
         return rev in self.basemap
     def bundlebase(self, rev):
         return self.basemap[rev]
     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.inbundle(rev):
             return revlog.revlog._chunk(self, rev)
         self.bundle.seek(self.start(rev))
         return self.bundle.read(self.length(rev))
 
     def revdiff(self, rev1, rev2):
         """return or calculate a delta between two revisions"""
         if self.inbundle(rev1) and self.inbundle(rev2):
             # hot path for bundle
             revb = self.rev(self.bundlebase(rev2))
             if revb == rev1:
                 return self._chunk(rev2)
         elif not self.inbundle(rev1) and not self.inbundle(rev2):
             return revlog.revlog.revdiff(self, rev1, rev2)
 
         return mdiff.textdiff(self.revision(self.node(rev1)),
                          self.revision(self.node(rev2)))
 
     def revision(self, nodeorrev):
         """return an uncompressed revision of a given node or revision
         number.
         """
         if isinstance(nodeorrev, int):
             rev = nodeorrev
             node = self.node(rev)
         else:
             node = nodeorrev
             rev = self.rev(node)
 
         if node == nullid:
             return ""
 
         text = None
         chain = []
         iter_node = node
         # reconstruct the revision if it is from a changegroup
         while self.inbundle(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 = mdiff.patches(text, [delta])
 
         p1, p2 = self.parents(node)
         if node != revlog.hash(text, p1, p2):
             raise error.RevlogError(_("integrity check failed on %s:%d")
                                      % (self.datafile, self.rev(node)))
 
         self._cache = (node, self.rev(node), text)
         return text
 
     def addrevision(self, text, transaction, link, p1=None, p2=None, d=None):
         raise NotImplementedError
     def addgroup(self, revs, linkmapper, transaction):
         raise NotImplementedError
     def strip(self, rev, minlink):
         raise NotImplementedError
     def checksize(self):
         raise NotImplementedError
 
 class bundlechangelog(bundlerevlog, changelog.changelog):
     def __init__(self, opener, bundle):
         changelog.changelog.__init__(self, opener)
         linkmapper = lambda x: x
         bundlerevlog.__init__(self, opener, self.indexfile, bundle,
                               linkmapper)
 
 class bundlemanifest(bundlerevlog, manifest.manifest):
     def __init__(self, opener, bundle, linkmapper):
         manifest.manifest.__init__(self, opener)
         bundlerevlog.__init__(self, opener, self.indexfile, bundle,
                               linkmapper)
 
 class bundlefilelog(bundlerevlog, filelog.filelog):
     def __init__(self, opener, path, bundle, linkmapper, repo):
         filelog.filelog.__init__(self, opener, path)
         bundlerevlog.__init__(self, opener, self.indexfile, bundle,
                               linkmapper)
         self._repo = repo
 
     def _file(self, f):
         self._repo.file(f)
 
 class bundlepeer(localrepo.localpeer):
     def canpush(self):
         return False
 
 class bundlerepository(localrepo.localrepository):
     def __init__(self, ui, path, bundlename):
         self._tempparent = None
         try:
             localrepo.localrepository.__init__(self, ui, path)
         except error.RepoError:
             self._tempparent = tempfile.mkdtemp()
             localrepo.instance(ui, self._tempparent, 1)
             localrepo.localrepository.__init__(self, ui, self._tempparent)
         self.ui.setconfig('phases', 'publish', False)
 
         if path:
             self._url = 'bundle:' + util.expandpath(path) + '+' + bundlename
         else:
             self._url = 'bundle:' + bundlename
 
         self.tempfile = None
         f = util.posixfile(bundlename, "rb")
         self.bundle = changegroup.readbundle(f, bundlename)
         if self.bundle.compressed():
             fdtemp, temp = tempfile.mkstemp(prefix="hg-bundle-",
                                             suffix=".hg10un", dir=self.path)
             self.tempfile = temp
             fptemp = os.fdopen(fdtemp, 'wb')
 
             try:
                 fptemp.write("HG10UN")
                 while True:
                     chunk = self.bundle.read(2**18)
                     if not chunk:
                         break
                     fptemp.write(chunk)
             finally:
                 fptemp.close()
 
             f = util.posixfile(self.tempfile, "rb")
             self.bundle = changegroup.readbundle(f, bundlename)
 
         # dict with the mapping 'filename' -> position in the bundle
         self.bundlefilespos = {}
 
     @localrepo.unfilteredpropertycache
     def changelog(self):
         # consume the header if it exists
         self.bundle.changelogheader()
         c = bundlechangelog(self.sopener, self.bundle)
         self.manstart = self.bundle.tell()
         return c
 
     @localrepo.unfilteredpropertycache
     def manifest(self):
         self.bundle.seek(self.manstart)
         # consume the header if it exists
         self.bundle.manifestheader()
         m = bundlemanifest(self.sopener, self.bundle, self.changelog.rev)
         self.filestart = self.bundle.tell()
         return m
 
     @localrepo.unfilteredpropertycache
     def manstart(self):
         self.changelog
         return self.manstart
 
     @localrepo.unfilteredpropertycache
     def filestart(self):
         self.manifest
         return self.filestart
 
     def url(self):
         return self._url
 
     def file(self, f):
         if not self.bundlefilespos:
             self.bundle.seek(self.filestart)
             while True:
                 chunkdata = self.bundle.filelogheader()
                 if not chunkdata:
                     break
                 fname = chunkdata['filename']
                 self.bundlefilespos[fname] = self.bundle.tell()
                 while True:
                     c = self.bundle.deltachunk(None)
                     if not c:
                         break
 
         if f[0] == '/':
             f = f[1:]
         if f in self.bundlefilespos:
             self.bundle.seek(self.bundlefilespos[f])
             return bundlefilelog(self.sopener, f, self.bundle,
                                  self.changelog.rev, self)
         else:
             return filelog.filelog(self.sopener, f)
 
     def close(self):
         """Close assigned bundle file immediately."""
         self.bundle.close()
         if self.tempfile is not None:
             os.unlink(self.tempfile)
         if self._tempparent:
             shutil.rmtree(self._tempparent, True)
 
     def cancopy(self):
         return False
 
     def peer(self):
         return bundlepeer(self)
 
     def getcwd(self):
         return os.getcwd() # always outside the repo
 
 
 def instance(ui, path, create):
     if create:
         raise util.Abort(_('cannot create new bundle repository'))
     parentpath = ui.config("bundle", "mainreporoot", "")
     if not parentpath:
         # try to find the correct path to the working directory repo
         parentpath = cmdutil.findrepo(os.getcwd())
         if parentpath is None:
             parentpath = ''
     if parentpath:
         # Try to make the full path relative so we get a nice, short URL.
         # In particular, we don't want temp dir names in test outputs.
         cwd = os.getcwd()
         if parentpath == cwd:
             parentpath = ''
         else:
             cwd = os.path.join(cwd,'')
             if parentpath.startswith(cwd):
                 parentpath = parentpath[len(cwd):]
     u = util.url(path)
     path = u.localpath()
     if u.scheme == 'bundle':
         s = path.split("+", 1)
         if len(s) == 1:
             repopath, bundlename = parentpath, s[0]
         else:
             repopath, bundlename = s
     else:
         repopath, bundlename = parentpath, path
     return bundlerepository(ui, repopath, bundlename)
 
 def getremotechanges(ui, repo, other, onlyheads=None, bundlename=None,
                      force=False):
     '''obtains a bundle of changes incoming from other
 
     "onlyheads" restricts the returned changes to those reachable from the
       specified heads.
     "bundlename", if given, stores the bundle to this file path permanently;
       otherwise it's stored to a temp file and gets deleted again when you call
       the returned "cleanupfn".
     "force" indicates whether to proceed on unrelated repos.
 
     Returns a tuple (local, csets, cleanupfn):
 
     "local" is a local repo from which to obtain the actual incoming
       changesets; it is a bundlerepo for the obtained bundle when the
       original "other" is remote.
     "csets" lists the incoming changeset node ids.
     "cleanupfn" must be called without arguments when you're done processing
       the changes; it closes both the original "other" and the one returned
       here.
     '''
     tmp = discovery.findcommonincoming(repo, other, heads=onlyheads,
                                        force=force)
     common, incoming, rheads = tmp
     if not incoming:
         try:
             if bundlename:
                 os.unlink(bundlename)
         except OSError:
             pass
         return repo, [], other.close
 
     bundle = None
     bundlerepo = None
     localrepo = other.local()
     if bundlename or not localrepo:
         # create a bundle (uncompressed if other repo is not local)
 
         if other.capable('getbundle'):
             cg = other.getbundle('incoming', common=common, heads=rheads)
         elif onlyheads is None and not other.capable('changegroupsubset'):
             # compat with older servers when pulling all remote heads
             cg = other.changegroup(incoming, "incoming")
             rheads = None
         else:
             cg = other.changegroupsubset(incoming, rheads, 'incoming')
         bundletype = localrepo and "HG10BZ" or "HG10UN"
         fname = bundle = changegroup.writebundle(cg, bundlename, bundletype)
         # keep written bundle?
         if bundlename:
             bundle = None
         if not localrepo:
             # use the created uncompressed bundlerepo
             localrepo = bundlerepo = bundlerepository(ui, repo.root, fname)
             # this repo contains local and other now, so filter out local again
             common = repo.heads()
 
     csets = localrepo.changelog.findmissing(common, rheads)
 
     def cleanup():
         if bundlerepo:
             bundlerepo.close()
         if bundle:
             os.unlink(bundle)
         other.close()
 
     return (localrepo, csets, cleanup)
-