Disabled threaded index-pack for known difficult repositories.

gclient_utils.py

 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Generic utils."""
 
 import codecs
 import cStringIO
 import logging
 import os
@@ skipping 12 matching lines @@
 import subprocess2
 
 
 RETRY_MAX = 3
 RETRY_INITIAL_SLEEP = 0.5
 
 
 _WARNINGS = []
 
 
+# These repos are known to cause OOM errors on 32-bit platforms, due the the
+# very large objects they contain.  It is not safe to use threaded index-pack
+# when cloning/fetching them.
+THREADED_INDEX_PACK_BLACKLIST = [
+  'https://chromium.googlesource.com/chromium/reference_builds/chrome_win.git'
+]
+
+
 class Error(Exception):
   """gclient exception class."""
   def __init__(self, msg, *args, **kwargs):
     index = getattr(threading.currentThread(), 'index', 0)
     if index:
       msg = '\n'.join('%d> %s' % (index, l) for l in msg.splitlines())
     super(Error, self).__init__(msg, *args, **kwargs)
 
 
 def PrintWarnings():
@@ skipping 940 matching lines @@
 
   The primary constraint is the address space of virtual memory.  The cache
   size limit is per-thread, and 32-bit systems can hit OOM errors if this
   parameter is set too high.
   """
   if platform.architecture()[0].startswith('64'):
     return '2g'
   else:
     return '512m'
 
-def DefaultIndexPackConfig():
+def DefaultIndexPackConfig(url=''):
   """Return reasonable default values for configuring git-index-pack.
 
   Experiments suggest that higher values for pack.threads don't improve
   performance."""
-  return ['-c', 'pack.threads=5', '-c',
-          'core.deltaBaseCacheLimit=%s' % DefaultDeltaBaseCacheLimit()]
+  cache_limit = DefaultDeltaBaseCacheLimit()
+  result = ['-c', 'core.deltaBaseCacheLimit=%s' % cache_limit]
+  if url in THREADED_INDEX_PACK_BLACKLIST:
+    result.extend(['-c', 'pack.threads=1'])
+  return result