Implement interface to Rietveld.

reviewbot/util.py

+# Copyright (c) 2013 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 email.utils
+
+
+def lazy_property(func):
+  """A decorator for lazy properties."""
+  name = '__lazy_' + func.__name__
+
+  def get_property(self, *args, **kwargs):
+    if not hasattr(self, name):
+      setattr(self, name, func(self, *args, **kwargs))
+    return getattr(self, name)
+
+  return property(get_property)
+
+
+class LazyDict(object):
+  """A simple immutable and lazy dictionary.
+
+  This looks up the actual key values on first access to the key and caches the
+  value to speed up subsequent accesses.
+  """
+
+  def __init__(self, lookup_fn):
+    self.items = {}
+    self.lookup = lookup_fn
+
+  def __getitem__(self, name):
+    if name not in self.items.keys():
+      self.items[name] = self.lookup(name)
+    return self.items[name]
+
+
+class ObjectDict(object):
+  """Wraps a dictionary to allow value retrieval in dot notation."""
+
+  def __init__(self, data):
+    self.data = data
+
+  def __getitem__(self, name):
+    val = self.data[name]
+    if type(val) == dict:
+      return ObjectDict(val)
+    return val
+
+  def __getattr__(self, name):
+    try:
+      return self[name]
+    except KeyError as e:
+      raise AttributeError(e)
+
+  def __iter__(self):
+    return self.data.iterkeys()
+
+
+def get_emails(string):
+  """Normalizes a string containing a list of email recepients.
+
+  Takes a string in the format present in mail headers and returns a list of
+  email addresses. For example, the input
+      'test@example.com, committers <committers@chromium.org>
+  will produce this return value:
+      [ 'test@example.com', 'committers@chromium.org' ]
+  """
+  return [entry[1] for entry in email.utils.getaddresses([string])]