1 files changed, 87 insertions, 0 deletions
diff --git a/chromium/third_party/catapult/common/py_trace_event/py_trace_event/trace_event_impl/decorators.py b/chromium/third_party/catapult/common/py_trace_event/py_trace_event/trace_event_impl/decorators.py
new file mode 100644
index 00000000000..dc753f1f61b
--- /dev/null
+++ b/chromium/third_party/catapult/common/py_trace_event/py_trace_event/trace_event_impl/decorators.py
@@ -0,0 +1,87 @@
+# Copyright 2016 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.
+import contextlib
+import inspect
+import time
+import functools
+
+import log
+from py_trace_event import trace_time
+
+
+@contextlib.contextmanager
+def trace(name, **kwargs):
+  category = "python"
+  start = trace_time.Now()
+  args_to_log = {key: repr(value) for key, value in kwargs.iteritems()}
+  log.add_trace_event("B", start, category, name, args_to_log)
+  try:
+    yield
+  finally:
+    end = trace_time.Now()
+    log.add_trace_event("E", end, category, name)
+
+def traced(*args):
+  def get_wrapper(func):
+    if inspect.isgeneratorfunction(func):
+      raise Exception("Can not trace generators.")
+
+    category = "python"
+
+    arg_spec = inspect.getargspec(func)
+    is_method = arg_spec.args and arg_spec.args[0] == "self"
+
+    def arg_spec_tuple(name):
+      arg_index = arg_spec.args.index(name)
+      defaults_length = len(arg_spec.defaults) if arg_spec.defaults else 0
+      default_index = arg_index + defaults_length - len(arg_spec.args)
+      if default_index >= 0:
+        default = arg_spec.defaults[default_index]
+      else:
+        default = None
+      return (name, arg_index, default)
+
+    args_to_log = map(arg_spec_tuple, arg_names)
+
+    @functools.wraps(func)
+    def traced_function(*args, **kwargs):
+      # Everything outside traced_function is done at decoration-time.
+      # Everything inside traced_function is done at run-time and must be fast.
+      if not log._enabled:  # This check must be at run-time.
+        return func(*args, **kwargs)
+
+      def get_arg_value(name, index, default):
+        if name in kwargs:
+          return kwargs[name]
+        elif index < len(args):
+          return args[index]
+        else:
+          return default
+
+      if is_method:
+        name = "%s.%s" % (args[0].__class__.__name__, func.__name__)
+      else:
+        name = "%s.%s" % (func.__module__, func.__name__)
+
+      # Be sure to repr before calling func. Argument values may change.
+      arg_values = {
+          name: repr(get_arg_value(name, index, default))
+          for name, index, default in args_to_log}
+
+      start = trace_time.Now()
+      log.add_trace_event("B", start, category, name, arg_values)
+      try:
+        return func(*args, **kwargs)
+      finally:
+        end = trace_time.Now()
+        log.add_trace_event("E", end, category, name)
+    return traced_function
+
+  no_decorator_arguments = len(args) == 1 and callable(args[0])
+  if no_decorator_arguments:
+    arg_names = ()
+    return get_wrapper(args[0])
+  else:
+    arg_names = args
+    return get_wrapper