manifest: remove _repo from manifestctx objects

manifest: remove _repo from manifestctx objects

We were storing the repo on the manifestctx objects so that they could access
the manifestlog via repo.manifestlog, which would refresh the structure if it
became out of date. This caused probems however when we want to have multiple
manifest logs in memory at once, like when transitioning to tree manifest from
flat manifests, since a tree manifest would try to access sub-trees via
repo.manifestlog[node], which was the flat manifest.

The solution is to just not store the repo, and instead store the manifestlog
that created this context. This removes the invalidation when the in memory
manifestlog becomes out of date, but people should probably not be keeping ctx's
around that long anyway.

--- a/mercurial/manifest.py	Wed Mar 01 15:50:01 2017 -0800
+++ b/mercurial/manifest.py	Wed Mar 01 16:39:48 2017 -0800
@@ -1261,8 +1261,6 @@
     class do not care about the implementation details of the actual manifests
     they receive (i.e. tree or flat or lazily loaded, etc)."""
     def __init__(self, opener, repo):
-        self._repo = repo
-
         usetreemanifest = False
         cachesize = 4
 
@@ -1309,7 +1307,7 @@
                     if node not in dirlog.nodemap:
                         raise LookupError(node, dirlog.indexfile,
                                           _('no node'))
-                m = treemanifestctx(self._repo, dir, node)
+                m = treemanifestctx(self, dir, node)
             else:
                 raise error.Abort(
                         _("cannot ask for manifest directory '%s' in a flat "
@@ -1320,9 +1318,9 @@
                     raise LookupError(node, self._revlog.indexfile,
                                       _('no node'))
             if self._treeinmem:
-                m = treemanifestctx(self._repo, '', node)
+                m = treemanifestctx(self, '', node)
             else:
-                m = manifestctx(self._repo, node)
+                m = manifestctx(self, node)
 
         if node != revlog.nullid:
             mancache = self._dirmancache.get(dir)
@@ -1337,18 +1335,18 @@
         self._revlog.clearcaches()
 
 class memmanifestctx(object):
-    def __init__(self, repo):
-        self._repo = repo
+    def __init__(self, manifestlog):
+        self._manifestlog = manifestlog
         self._manifestdict = manifestdict()
 
     def _revlog(self):
-        return self._repo.manifestlog._revlog
+        return self._manifestlog._revlog
 
     def new(self):
-        return memmanifestctx(self._repo)
+        return memmanifestctx(self._manifestlog)
 
     def copy(self):
-        memmf = memmanifestctx(self._repo)
+        memmf = memmanifestctx(self._manifestlog)
         memmf._manifestdict = self.read().copy()
         return memmf
 
@@ -1363,8 +1361,8 @@
     """A class representing a single revision of a manifest, including its
     contents, its parent revs, and its linkrev.
     """
-    def __init__(self, repo, node):
-        self._repo = repo
+    def __init__(self, manifestlog, node):
+        self._manifestlog = manifestlog
         self._data = None
 
         self._node = node
@@ -1377,16 +1375,16 @@
         #self.linkrev = revlog.linkrev(rev)
 
     def _revlog(self):
-        return self._repo.manifestlog._revlog
+        return self._manifestlog._revlog
 
     def node(self):
         return self._node
 
     def new(self):
-        return memmanifestctx(self._repo)
+        return memmanifestctx(self._manifestlog)
 
     def copy(self):
-        memmf = memmanifestctx(self._repo)
+        memmf = memmanifestctx(self._manifestlog)
         memmf._manifestdict = self.read().copy()
         return memmf
 
@@ -1431,7 +1429,7 @@
         if revlog._usemanifestv2:
             # Need to perform a slow delta
             r0 = revlog.deltaparent(revlog.rev(self._node))
-            m0 = self._repo.manifestlog[revlog.node(r0)].read()
+            m0 = self._manifestlog[revlog.node(r0)].read()
             m1 = self.read()
             md = manifestdict()
             for f, ((n0, fl0), (n1, fl1)) in m0.diff(m1).iteritems():
@@ -1449,19 +1447,19 @@
         return self.read().find(key)
 
 class memtreemanifestctx(object):
-    def __init__(self, repo, dir=''):
-        self._repo = repo
+    def __init__(self, manifestlog, dir=''):
+        self._manifestlog = manifestlog
         self._dir = dir
         self._treemanifest = treemanifest()
 
     def _revlog(self):
-        return self._repo.manifestlog._revlog
+        return self._manifestlog._revlog
 
     def new(self, dir=''):
-        return memtreemanifestctx(self._repo, dir=dir)
+        return memtreemanifestctx(self._manifestlog, dir=dir)
 
     def copy(self):
-        memmf = memtreemanifestctx(self._repo, dir=self._dir)
+        memmf = memtreemanifestctx(self._manifestlog, dir=self._dir)
         memmf._treemanifest = self._treemanifest.copy()
         return memmf
 
@@ -1470,13 +1468,13 @@
 
     def write(self, transaction, link, p1, p2, added, removed):
         def readtree(dir, node):
-            return self._repo.manifestlog.get(dir, node).read()
+            return self._manifestlog.get(dir, node).read()
         return self._revlog().add(self._treemanifest, transaction, link, p1, p2,
                                   added, removed, readtree=readtree)
 
 class treemanifestctx(object):
-    def __init__(self, repo, dir, node):
-        self._repo = repo
+    def __init__(self, manifestlog, dir, node):
+        self._manifestlog = manifestlog
         self._dir = dir
         self._data = None
 
@@ -1490,7 +1488,7 @@
         #self.linkrev = revlog.linkrev(rev)
 
     def _revlog(self):
-        return self._repo.manifestlog._revlog.dirlog(self._dir)
+        return self._manifestlog._revlog.dirlog(self._dir)
 
     def read(self):
         if self._data is None:
@@ -1504,8 +1502,7 @@
                 def readsubtree(dir, subm):
                     # Set verify to False since we need to be able to create
                     # subtrees for trees that don't exist on disk.
-                    return self._repo.manifestlog.get(dir, subm,
-                                                      verify=False).read()
+                    return self._manifestlog.get(dir, subm, verify=False).read()
                 m.read(gettext, readsubtree)
                 m.setnode(self._node)
                 self._data = m
@@ -1521,10 +1518,10 @@
         return self._node
 
     def new(self, dir=''):
-        return memtreemanifestctx(self._repo, dir=dir)
+        return memtreemanifestctx(self._manifestlog, dir=dir)
 
     def copy(self):
-        memmf = memtreemanifestctx(self._repo, dir=self._dir)
+        memmf = memtreemanifestctx(self._manifestlog, dir=self._dir)
         memmf._treemanifest = self.read().copy()
         return memmf
 
@@ -1551,7 +1548,7 @@
         else:
             # Need to perform a slow delta
             r0 = revlog.deltaparent(revlog.rev(self._node))
-            m0 = self._repo.manifestlog.get(self._dir, revlog.node(r0)).read()
+            m0 = self._manifestlog.get(self._dir, revlog.node(r0)).read()
             m1 = self.read()
             md = treemanifest(dir=self._dir)
             for f, ((n0, fl0), (n1, fl1)) in m0.diff(m1).iteritems():