introduce unionrepo repository class for viewing union of repositories

rhodecode/lib/unionrepo.py

@@ -0,0 +1,181
+# unionrepo.py - repository class for viewing union of repositories
+#
+# Derived from Mercurial 2.5 bundlerepo.py
+# Copyright 2006, 2007 Benoit Boissinot <[e-mail]>
+# Copyright 2013 Unity Technologies, Mads Kiilerich <[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 in-memory pull of one local repository to another.
+"""
+
+from mercurial.node import nullid
+from mercurial import util, mdiff
+from mercurial import localrepo, changelog, manifest, filelog, revlog
+
+class unionrevlog(revlog.revlog):
+    def __init__(self, opener, indexfile, revlog2, linkmapper):
+        # How it works:
+        # To retrieve a revision, we just need to know the node id so we can
+        # look it up in revlog2.
+        #
+        # basemap is indexed with revisions coming from the second revlog.
+        #
+        # To differentiate a rev in the second revlog from a rev in the revlog,
+        # we check revision against basemap.
+        revlog.revlog.__init__(self, opener, indexfile)
+        self.revlog2 = revlog2
+
+        self.basemap = {} # mapping rev that is in revlog2 to ... nothing
+        n = len(self)
+        self.bundlerevs = set() # used by 'bundle()' revset expression
+        for rev2 in self.revlog2:
+            rev = self.revlog2.index[rev2]
+            # rev numbers - in revlog2, very different from self.rev
+            _start, _csize, _rsize, _base, linkrev, p1rev, p2rev, node = rev
+
+            if linkmapper is None: # link is to same revlog
+                assert linkrev == rev2 # we never link back
+                link = n
+            else: # rev must be mapped from repo2 cl to unified cl by linkmapper
+                link = linkmapper(linkrev)
+
+            if node in self.nodemap:
+                # this happens for for the common revlog revisions
+                self.bundlerevs.add(self.nodemap[node])
+                continue
+
+            p1node = self.revlog2.node(p1rev)
+            p2node = self.revlog2.node(p2rev)
+
+            e = (None, None, None, None,
+                 link, self.rev(p1node), self.rev(p2node), node)
+            self.basemap[n] = None
+            self.index.insert(-1, e)
+            self.nodemap[node] = n
+            self.bundlerevs.add(n)
+            n += 1
+
+    def _chunk(self, rev):
+        if rev not in self.basemap:
+            return revlog.revlog._chunk(self, rev)
+        return self.revlog2._chunk(self.node(rev))
+
+    def revdiff(self, rev1, rev2):
+        """return or calculate a delta between two revisions"""
+        if rev1 in self.basemap and rev2 in self.basemap:
+            return self.revlog2.revdiff(
+                self.revlog2.rev(self.node(rev1)),
+                self.revlog2.rev(self.node(rev2)))
+        elif rev1 not in self.basemap and rev2 not in self.basemap:
+            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 ""
+
+        if rev in self.basemap:
+            text = self.revlog2.revision(node)
+            self._cache = (node, rev, text)
+        else:
+            text = revlog.revlog.revision(self, rev)
+            # already cached
+        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 unionchangelog(unionrevlog, changelog.changelog):
+    def __init__(self, opener, opener2):
+        changelog.changelog.__init__(self, opener)
+        linkmapper = None
+        changelog2 = changelog.changelog(opener2)
+        unionrevlog.__init__(self, opener, self.indexfile, changelog2,
+                             linkmapper)
+
+class unionmanifest(unionrevlog, manifest.manifest):
+    def __init__(self, opener, opener2, linkmapper):
+        manifest.manifest.__init__(self, opener)
+        manifest2 = manifest.manifest(opener2)
+        unionrevlog.__init__(self, opener, self.indexfile, manifest2,
+                             linkmapper)
+
+class unionfilelog(unionrevlog, filelog.filelog):
+    def __init__(self, opener, path, opener2, linkmapper, repo):
+        filelog.filelog.__init__(self, opener, path)
+        filelog2 = filelog.filelog(opener2, path)
+        unionrevlog.__init__(self, opener, self.indexfile, filelog2,
+                             linkmapper)
+        self._repo = repo
+
+    def _file(self, f):
+        self._repo.file(f)
+
+class unionpeer(localrepo.localpeer):
+    def canpush(self):
+        return False
+
+class unionrepository(localrepo.localrepository):
+    def __init__(self, ui, path, path2):
+        localrepo.localrepository.__init__(self, ui, path)
+        self.ui.setconfig('phases', 'publish', False)
+
+        self._url = 'union:%s+%s' % (util.expandpath(path),
+                                     util.expandpath(path2))
+        self.repo2 = localrepo.localrepository(ui, path2)
+
+    @util.propertycache
+    def changelog(self):
+        return unionchangelog(self.sopener, self.repo2.sopener)
+
+    def _clrev(self, rev2):
+        """map from repo2 changelog rev to temporary rev in self.changelog"""
+        node = self.repo2.changelog.node(rev2)
+        return self.changelog.rev(node)
+
+    @util.propertycache
+    def manifest(self):
+        return unionmanifest(self.sopener, self.repo2.sopener,
+                             self._clrev)
+
+    def url(self):
+        return self._url
+
+    def file(self, f):
+        return unionfilelog(self.sopener, f, self.repo2.sopener,
+                            self._clrev, self)
+
+    def close(self):
+        self.repo2.close()
+
+    def cancopy(self):
+        return False
+
+    def peer(self):
+        return unionpeer(self)
+
+def instance(ui, path, create):
+    u = util.url(path)
+    assert u.scheme == 'union'
+    repopath, repopath2 = u.path.split("+", 1)
+    return unionrepository(ui, repopath, repopath2)