[PATCH 1 of 5 V2] manifest: break mancache into two caches

[Durham Goode]

# HG changeset patch
# User Durham Goode <durham at fb.com>
# Date 1471465513 25200
#      Wed Aug 17 13:25:13 2016 -0700
# Node ID b5eca5d531599261641e1d2d3f9f2e60b6538da7
# Parent  997e8cf4d0a29d28759e38659736cb3d1cf9ef3f
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}