[PATCH 2 of 3] revlog: drop local assignment of cache variable

[Gregory Szorc]

# HG changeset patch
# User Gregory Szorc <gregory.szorc at gmail.com>
# Date 1442096207 25200
#      Sat Sep 12 15:16:47 2015 -0700
# Node ID 9b0f250a7ac06af053725d735aa551eed9d3e66b
# Parent  40de7615bcdb6715732f3ac64b76c62bfe954387
revlog: drop local assignment of cache variable

The purpose of this code was to provide thread safety. With the
conversion of hgweb to use separate localrepository instances per
request/thread, we should no longer have any consumers that need to
access revlog instances from multiple threads. Remove the code.

diff --git a/mercurial/revlog.py b/mercurial/revlog.py
--- a/mercurial/revlog.py
+++ b/mercurial/revlog.py
@@ -1048,16 +1048,15 @@ class revlog(object):
         else:
             node = nodeorrev
             rev = None
 
-        _cache = self._cache # grab local copy of cache to avoid thread race
         cachedrev = None
         if node == nullid:
             return ""
-        if _cache:
-            if _cache[0] == node:
-                return _cache[2]
-            cachedrev = _cache[1]
+        if self._cache:
+            if self._cache[0] == node:
+                return self._cache[2]
+            cachedrev = self._cache[1]
 
         # look up what we need to read
         text = None
         if rev is None:
@@ -1083,9 +1082,9 @@ class revlog(object):
             e = index[iterrev]
 
         if iterrev == cachedrev:
             # cache hit
-            text = _cache[2]
+            text = self._cache[2]
         else:
             chain.append(iterrev)
         chain.reverse()