[NaCl SDK] Refactor sdk_update*.

native_client_sdk/src/build_tools/sdk_tools/config.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.
+
+import json
+import logging
+import urlparse
+
+SOURCE_WHITELIST = [
+  'https://commondatastorage.googleapis.com/nativeclient-mirror/nacl/nacl_sdk',
+]
+
+def IsSourceValid(url):
+  scheme, host, path, _, _, _ = urlparse.urlparse(url)
+  for allowed_url in SOURCE_WHITELIST:
+    allowed_scheme, allowed_host, allowed_path_prefix, _, _, _ = \
+        urlparse.urlparse(allowed_url)
+    if (scheme == allowed_scheme and host == allowed_host and
+        path.startswith(allowed_path_prefix)):
+      return True
+  return False
+
+
+class Config(dict):
+  def __init__(self, data=None):
+    dict.__init__(self)
+    if data:
+      self.update(data)
+    else:
+      self.sources = []
+
+  def ToJson(self):
+    return json.dumps(self, sort_keys=False, indent=2)
+
+  def __getattr__(self, name):
+    return self.__getitem__(name)
+
+  def __setattr__(self, name, value):
+    return self.__setitem__(name, value)
+
+  def AddSource(self, source):
+    if not IsSourceValid(source):
+      logging.warn('Only whitelisted sources are allowed. Ignoring \"%s\".' % (
+          source,))
+      return
+
+    if source in self.sources:
+      logging.info('Source \"%s\" already in Config.' % (source,))
+      return
+    self.sources.append(source)
+
+  def RemoveSource(self, source):
+    if source not in self.sources:
+      logging.warn('Source \"%s\" not in Config.' % (source,))
+      return
+    self.sources.remove(source)
+
+  def RemoveAllSources(self):
+    if not self.sources:
+      logging.info('No sources to remove.')
+      return
+    self.sources = []