Rationalize the git config settings for index-pack performance.

gclient_scm.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.
 
 """Gclient-specific SCM-specific operations."""
 
 import logging
 import os
 import posixpath
 import re
@@ skipping 212 matching lines @@
 
     gclient_utils.CheckCallAndFilter(cmd4, **kwargs)
 
   def _FetchAndReset(self, revision, file_list, options):
     """Equivalent to git fetch; git reset."""
     quiet = []
     if not options.verbose:
       quiet = ['--quiet']
     self._UpdateBranchHeads(options, fetch=False)
 
-    fetch_cmd = [
-      '-c', 'core.deltaBaseCacheLimit=2g', 'fetch', self.remote, '--prune']
+    cfg = gclient_utils.DefaultIndexPackConfig()
+    fetch_cmd = cfg + ['fetch', self.remote, '--prune']
     self._Run(fetch_cmd + quiet, options, retry=True)
     self._Run(['reset', '--hard', revision] + quiet, options)
     self.UpdateSubmoduleConfig()
     if file_list is not None:
       files = self._Capture(['ls-files']).splitlines()
       file_list.extend([os.path.join(self.checkout_path, f) for f in files])
 
   def update(self, options, args, file_list):
     """Runs git to update or transparently checkout the working copy.
 
@@ skipping 449 matching lines @@
     revision is a branch head. If it is a tag or a specific commit, then we
     leave HEAD detached as it makes future updates simpler -- in this case the
     user should first create a new branch or switch to an existing branch before
     making changes in the repo."""
     if not options.verbose:
       # git clone doesn't seem to insert a newline properly before printing
       # to stdout
       print('')
     template_path = os.path.join(
         os.path.dirname(THIS_FILE_PATH), 'git-templates')
-    clone_cmd = ['-c', 'core.deltaBaseCacheLimit=2g', 'clone', '--no-checkout',
-                 '--progress', '--template=%s' % template_path]
+    cfg = gclient_utils.DefaultIndexPackConfig()
+    clone_cmd = cfg + [
+        'clone', '--no-checkout', '--progress', '--template=%s' % template_path]
     if self.cache_dir:
       clone_cmd.append('--shared')
     if options.verbose:
       clone_cmd.append('--verbose')
     clone_cmd.append(url)
     # If the parent directory does not exist, Git clone on Windows will not
     # create it, so we need to do it manually.
     parent_dir = os.path.dirname(self.checkout_path)
     gclient_utils.safe_makedirs(parent_dir)
     tmp_dir = tempfile.mkdtemp(
@@ skipping 189 matching lines @@
         cwd=cwd or self.checkout_path).strip()
 
   def _UpdateBranchHeads(self, options, fetch=False):
     """Adds, and optionally fetches, "branch-heads" refspecs if requested."""
     if hasattr(options, 'with_branch_heads') and options.with_branch_heads:
       config_cmd = ['config', 'remote.%s.fetch' % self.remote,
                     '+refs/branch-heads/*:refs/remotes/branch-heads/*',
                     '^\\+refs/branch-heads/\\*:.*$']
       self._Run(config_cmd, options)
       if fetch:
-        fetch_cmd = ['-c', 'core.deltaBaseCacheLimit=2g', 'fetch', self.remote]
+        cfg = gclient_utils.DefaultIndexPackConfig()
+        fetch_cmd =  cfg + ['fetch', self.remote]
         if options.verbose:
           fetch_cmd.append('--verbose')
         self._Run(fetch_cmd, options, retry=True)
 
   def _Run(self, args, options, **kwargs):
     kwargs.setdefault('cwd', self.checkout_path)
     git_filter = not options.verbose
     if git_filter:
       kwargs['filter_fn'] = gclient_utils.GitFilter(kwargs.get('filter_fn'))
       kwargs.setdefault('print_stdout', False)
@@ skipping 475 matching lines @@
       new_command.append('--force')
       if command[0] != 'checkout' and scm.SVN.AssertVersion('1.6')[0]:
         new_command.extend(('--accept', 'theirs-conflict'))
     elif options.manually_grab_svn_rev:
       new_command.append('--force')
       if command[0] != 'checkout' and scm.SVN.AssertVersion('1.6')[0]:
         new_command.extend(('--accept', 'postpone'))
     elif command[0] != 'checkout' and scm.SVN.AssertVersion('1.6')[0]:
       new_command.extend(('--accept', 'postpone'))
     return new_command