# HG changeset patch
# User FUJIWARA Katsunori <foozy@lares.dti.ne.jp>
# Date 1418915516 -32400
# Node ID d74eb8d477d5b87fd7771560f978f4e1dad68db6
# Parent  a4679a74df144213aa2e6b6d86cf6d02eb193c10
memctx: calculate manifest more efficiently

Before this patch, "memctx._manifest" updates all entries in the
(parent) manifest. But this is inefficiency, because almost all files
may be clean in that context.

On the other hand, just updating entries for changed "files" specified
at construction causes unexpected abortion, when there is at least one
newly removed file (see issue4470 for detail).

To calculate manifest more efficiently, this patch replaces
"pman.iteritems()" for the loop by "self._status.modified" to avoid
updating entries for clean or removed files

Examination of removal is also omitted, because removed files aren't
treated in this loop (= "self[f]" returns not None always).

diff -r a4679a74df14 -r d74eb8d477d5 mercurial/context.py
--- a/mercurial/context.py	Thu Dec 18 16:41:59 2014 -0600
+++ b/mercurial/context.py	Fri Dec 19 00:11:56 2014 +0900
@@ -1633,10 +1633,9 @@
 
         # keep this simple for now; just worry about p1
         pctx = self._parents[0]
-        pman = pctx.manifest()
         man = pctx.manifest().copy()
 
-        for f, fnode in pman.iteritems():
+        for f in self._status.modified:
             p1node = nullid
             p2node = nullid
             p = pctx[f].parents() # if file isn't in pctx, check p2?
@@ -1644,12 +1643,7 @@
                 p1node = p[0].node()
                 if len(p) > 1:
                     p2node = p[1].node()
-            fctx = self[f]
-            if fctx is None:
-                # removed file
-                del man[f]
-            else:
-                man[f] = revlog.hash(fctx.data(), p1node, p2node)
+            man[f] = revlog.hash(self[f].data(), p1node, p2node)
 
         for f in self._status.added:
             man[f] = revlog.hash(self[f].data(), nullid, nullid)