Add flushing to gclient revert.

gclient_scm.py

 # Copyright (c) 2010 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
 import subprocess
 import time
+import sys

[chase, 2010/08/18 16:59:57]

nit: move above 'import time'

 
 import scm
 import gclient_utils
 
 
 class DiffFilterer(object):
   """Simple class which tracks which file is being diffed and
   replaces instances of its file name in the original and
   working copy lines of the svn/git diff output."""
   index_string = "Index: "
@@ skipping 843 matching lines @@
     doesn't know about them.
     """
     path = os.path.join(self._root_dir, self.relpath)
     if not os.path.isdir(path):
       # svn revert won't work if the directory doesn't exist. It needs to
       # checkout instead.
       print("\n_____ %s is missing, synching instead" % self.relpath)
       # Don't reuse the args.
       return self.update(options, [], file_list)
 
+    # Do a flush of sys.stdout every 10 secs or so otherwise it may never be
+    # flushed fast enough for buildbot.
+    last_flushed_at = time.time()
+    sys.stdout.flush()
+
     for file_status in scm.SVN.CaptureStatus(path):
       file_path = os.path.join(path, file_status[1])
       if file_status[0][0] == 'X':
         # Ignore externals.
         logging.info('Ignoring external %s' % file_path)
         continue
 
       if logging.getLogger().isEnabledFor(logging.INFO):
         logging.info('%s%s' % (file[0], file[1]))
       else:
         print(file_path)
+        # Flush at least 10 seconds between line writes.  We wait at least 10
+        # seconds to avoid overloading the reader that called us with output,
+        # which can slow busy readers down.
+        if (time.time() - last_flushed_at) > 10:
+          last_flushed_at = time.time()
+          sys.stdout.flush()
+
       if file_status[0].isspace():
         logging.error('No idea what is the status of %s.\n'
                       'You just found a bug in gclient, please ping '
                       'maruel@chromium.org ASAP!' % file_path)
       # svn revert is really stupid. It fails on inconsistent line-endings,
       # on switched directories, etc. So take no chance and delete everything!
       try:
         if not os.path.exists(file_path):
           pass
         elif os.path.isfile(file_path) or os.path.islink(file_path):
@@ skipping 51 matching lines @@
 
     This method returns a new list to be used as a command."""
     new_command = command[:]
     if revision:
       new_command.extend(['--revision', str(revision).strip()])
     # --force was added to 'svn update' in svn 1.5.
     if ((options.force or options.manually_grab_svn_rev) and
         scm.SVN.AssertVersion("1.5")[0]):
       new_command.append('--force')
     return new_command