Recipe package system.

recipe_engine/third_party/google/protobuf/message_factory.py

+# Protocol Buffers - Google's data interchange format
+# Copyright 2008 Google Inc.  All rights reserved.
+# http://code.google.com/p/protobuf/
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Provides a factory class for generating dynamic messages."""
+
+__author__ = 'matthewtoia@google.com (Matt Toia)'
+
+from google.protobuf import descriptor_database
+from google.protobuf import descriptor_pool
+from google.protobuf import message
+from google.protobuf import reflection
+
+
+class MessageFactory(object):
+  """Factory for creating Proto2 messages from descriptors in a pool."""
+
+  def __init__(self):
+    """Initializes a new factory."""
+    self._classes = {}
+
+  def GetPrototype(self, descriptor):
+    """Builds a proto2 message class based on the passed in descriptor.
+
+    Passing a descriptor with a fully qualified name matching a previous
+    invocation will cause the same class to be returned.
+
+    Args:
+      descriptor: The descriptor to build from.
+
+    Returns:
+      A class describing the passed in descriptor.
+    """
+
+    if descriptor.full_name not in self._classes:
+      result_class = reflection.GeneratedProtocolMessageType(
+          descriptor.name.encode('ascii', 'ignore'),
+          (message.Message,),
+          {'DESCRIPTOR': descriptor})
+      self._classes[descriptor.full_name] = result_class
+      for field in descriptor.fields:
+        if field.message_type:
+          self.GetPrototype(field.message_type)
+    return self._classes[descriptor.full_name]
+
+
+_DB = descriptor_database.DescriptorDatabase()
+_POOL = descriptor_pool.DescriptorPool(_DB)
+_FACTORY = MessageFactory()
+
+
+def GetMessages(file_protos):
+  """Builds a dictionary of all the messages available in a set of files.
+
+  Args:
+    file_protos: A sequence of file protos to build messages out of.
+
+  Returns:
+    A dictionary containing all the message types in the files mapping the
+    fully qualified name to a Message subclass for the descriptor.
+  """
+
+  result = {}
+  for file_proto in file_protos:
+    _DB.Add(file_proto)
+  for file_proto in file_protos:
+    for desc in _GetAllDescriptors(file_proto.message_type, file_proto.package):
+      result[desc.full_name] = _FACTORY.GetPrototype(desc)
+  return result
+
+
+def _GetAllDescriptors(desc_protos, package):
+  """Gets all levels of nested message types as a flattened list of descriptors.
+
+  Args:
+    desc_protos: The descriptor protos to process.
+    package: The package where the protos are defined.
+
+  Yields:
+    Each message descriptor for each nested type.
+  """
+
+  for desc_proto in desc_protos:
+    name = '.'.join((package, desc_proto.name))
+    yield _POOL.FindMessageTypeByName(name)
+    for nested_desc in _GetAllDescriptors(desc_proto.nested_type, name):
+      yield nested_desc