Remove the class StdoutAnnotated and clones the object instead.

The end goal is to remove options.stdout, to remove a lot of bookkeeping.

TEST=none
BUG=none

Review URL: http://codereview.chromium.org/3418014

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@59792 0039d316-1c4b-4281-b951-d872f2087c98

gclient.py

@@ -1170,6 +1170,10 @@ def Main(argv):
   """Doesn't parse the arguments here, just find the right subcommand to
   execute."""
   try:
+    # Make stdout auto-flush so buildbot doesn't kill us during lengthy
+    # operations. Python as a strong tendency to buffer sys.stdout.
+    sys.stdout = gclient_utils.MakeFileAutoFlush(sys.stdout)
+
     # Do it late so all commands are listed.
     CMDhelp.usage = ('\n\nCommands are:\n' + '\n'.join([
         '  %-10s %s' % (fn[3:], Command(fn[3:]).__doc__.split('\n')[0].strip())
@@ -1198,8 +1202,8 @@ def Main(argv):
       options.entries_filename = options.config_filename + '_entries'
       if options.jobs < 1:
         parser.error('--jobs must be 1 or higher')
-      # Always autoflush so buildbot doesn't kill us during lengthy operations.
-      options.stdout = gclient_utils.StdoutAutoFlush(sys.stdout)
+      # TODO(maruel): Temporary, to be removed.
+      options.stdout = sys.stdout
 
       # These hacks need to die.
       if not hasattr(options, 'revisions'):

gclient_utils.py

@@ -295,31 +295,48 @@ def CheckCallAndFilterAndHeader(args, always=False, **kwargs):
   return CheckCallAndFilter(args, **kwargs)
 
 
-class StdoutAutoFlush(object):
-  """Automatically flush after N seconds."""
-  def __init__(self, stdout, delay=10):
-    self.lock = threading.Lock()
-    self.stdout = stdout
-    self.delay = delay
-    self.last_flushed_at = time.time()
-    self.stdout.flush()
-
-  def write(self, out):
-    """Thread-safe."""
-    self.stdout.write(out)
+def SoftClone(obj):
+  """Clones an object. copy.copy() doesn't work on 'file' objects."""
+  class NewObject(object): pass
+  new_obj = NewObject()
+  for member in dir(obj):
+    if member.startswith('_'):
+      continue
+    setattr(new_obj, member, getattr(obj, member))
+  return new_obj
+
+
+def MakeFileAutoFlush(fileobj, delay=10):
+  """Creates a file object clone to automatically flush after N seconds."""
+  if hasattr(fileobj, 'last_flushed_at'):
+    # Already patched. Just update delay.
+    fileobj.delay = delay
+    return fileobj
+
+  new_fileobj = SoftClone(fileobj)
+  new_fileobj.lock = threading.Lock()
+  new_fileobj.last_flushed_at = time.time()
+  new_fileobj.delay = delay
+  new_fileobj.old_auto_flush_write = fileobj.write
+  # Silence pylint.
+  new_fileobj.flush = fileobj.flush
+
+  def auto_flush_write(out):
+    new_fileobj.old_auto_flush_write(out)
     should_flush = False
-    self.lock.acquire()
+    new_fileobj.lock.acquire()
     try:
-      if (time.time() - self.last_flushed_at) > self.delay:
+      if (new_fileobj.delay and
+          (time.time() - new_fileobj.last_flushed_at) > new_fileobj.delay):
         should_flush = True
-        self.last_flushed_at = time.time()
+        new_fileobj.last_flushed_at = time.time()
     finally:
-      self.lock.release()
+      new_fileobj.lock.release()
     if should_flush:
-      self.stdout.flush()
+      new_fileobj.flush()
 
-  def flush(self):
-    self.stdout.flush()
+  new_fileobj.write = auto_flush_write
+  return new_fileobj
 
 
 class StdoutAnnotated(object):

tests/gclient_utils_test.py

@@ -25,10 +25,10 @@ class GclientUtilsUnittest(GclientUtilBase):
         'CheckCall', 'CheckCallError', 'CheckCallAndFilter',
         'CheckCallAndFilterAndHeader', 'Error', 'ExecutionQueue', 'FileRead',
         'FileWrite', 'FindFileUpwards', 'FindGclientRoot',
-        'GetGClientRootAndEntries', 'GetNamedNodeText',
+        'GetGClientRootAndEntries', 'GetNamedNodeText', 'MakeFileAutoFlush',
         'GetNodeNamedAttributeText', 'PathDifference', 'ParseXML', 'Popen',
-        'PrintableObject', 'RemoveDirectory', 'SplitUrlRevision',
-        'StdoutAnnotated', 'StdoutAutoFlush', 'SyntaxErrorToError', 'WorkItem',
+        'PrintableObject', 'RemoveDirectory', 'SoftClone', 'SplitUrlRevision',
+        'StdoutAnnotated', 'SyntaxErrorToError', 'WorkItem',
         'copy', 'errno', 'logging', 'os', 'Queue', 're', 'stat', 'subprocess',
         'sys','threading', 'time', 'xml',
     ]