[PATCH 1 of 5] manifest: break mancache into two caches

[Durham Goode]

# HG changeset patch
# User Durham Goode <durham at fb.com>
# Date 1470696646 25200
#      Mon Aug 08 15:50:46 2016 -0700
# Node ID f91cdd4315bbc92ad893c8084c0347c218399ce3
# Parent  37b6f0ec6241a62de90737409458cd622e2fac0d
manifest: break mancache into two caches

The old manifest cache cached both the inmemory representation and the raw text.
As part of the manifest refactor we want to separate the storage format from the
in memory representation, so let's split this cache into two caches.

This will let other manifest implementations participate in the in memory cache,
while allowing the revlog based implementations to still depend on the full text
caching where necessary.

diff --git a/mercurial/bundlerepo.py b/mercurial/bundlerepo.py
--- a/mercurial/bundlerepo.py
+++ b/mercurial/bundlerepo.py
@@ -205,7 +205,7 @@ class bundlemanifest(bundlerevlog, manif
             node = self.node(node)
 
         if node in self._mancache:
-            result = self._mancache[node][0].text()
+            result = self._mancache[node].text()
         else:
             result = manifest.manifest.revision(self, nodeorrev)
         return result
diff --git a/mercurial/manifest.py b/mercurial/manifest.py
--- a/mercurial/manifest.py
+++ b/mercurial/manifest.py
@@ -908,6 +908,7 @@ class manifest(revlog.revlog):
             usetreemanifest = opts.get('treemanifest', usetreemanifest)
             usemanifestv2 = opts.get('manifestv2', usemanifestv2)
         self._mancache = util.lrucachedict(cachesize)
+        self._fulltextcache = util.lrucachedict(cachesize)
         self._treeinmem = usetreemanifest
         self._treeondisk = usetreemanifest
         self._usemanifestv2 = usemanifestv2
@@ -1000,7 +1001,7 @@ class manifest(revlog.revlog):
         if node == revlog.nullid:
             return self._newmanifest() # don't upset local cache
         if node in self._mancache:
-            return self._mancache[node][0]
+            return self._mancache[node]
         if self._treeondisk:
             def gettext():
                 return self.revision(node)
@@ -1014,7 +1015,8 @@ class manifest(revlog.revlog):
             text = self.revision(node)
             m = self._newmanifest(text)
             arraytext = array.array('c', text)
-        self._mancache[node] = (m, arraytext)
+        self._mancache[node] = m
+        self._fulltextcache[node] = arraytext
         return m
 
     def readshallow(self, node):
@@ -1034,7 +1036,7 @@ class manifest(revlog.revlog):
             return None, None
 
     def add(self, m, transaction, link, p1, p2, added, removed):
-        if (p1 in self._mancache and not self._treeinmem
+        if (p1 in self._fulltextcache and not self._treeinmem
             and not self._usemanifestv2):
             # If our first parent is in the manifest cache, we can
             # compute a delta here using properties we know about the
@@ -1046,7 +1048,7 @@ class manifest(revlog.revlog):
             work = heapq.merge([(x, False) for x in added],
                                [(x, True) for x in removed])
 
-            arraytext, deltatext = m.fastdelta(self._mancache[p1][1], work)
+            arraytext, deltatext = m.fastdelta(self._fulltextcache[p1], work)
             cachedelta = self.rev(p1), deltatext
             text = util.buffer(arraytext)
             n = self.addrevision(text, transaction, link, p1, p2, cachedelta)
@@ -1065,7 +1067,8 @@ class manifest(revlog.revlog):
                 n = self.addrevision(text, transaction, link, p1, p2)
                 arraytext = array.array('c', text)
 
-        self._mancache[n] = (m, arraytext)
+        self._mancache[n] = m
+        self._fulltextcache[n] = arraytext
 
         return n
 
@@ -1092,5 +1095,6 @@ class manifest(revlog.revlog):
 
     def clearcaches(self):
         super(manifest, self).clearcaches()
+        self._fulltextcache.clear()
         self._mancache.clear()
         self._dirlogcache = {'': self}