third_party/protobuf: Update to HEAD (83d681ee2c)

third_party/protobuf/python/google/protobuf/pyext/message_factory.h

+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// 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.
+
+#ifndef GOOGLE_PROTOBUF_PYTHON_CPP_MESSAGE_FACTORY_H__
+#define GOOGLE_PROTOBUF_PYTHON_CPP_MESSAGE_FACTORY_H__
+
+#include <Python.h>
+
+#include <google/protobuf/stubs/hash.h>
+#include <google/protobuf/descriptor.h>
+#include <google/protobuf/pyext/descriptor_pool.h>
+
+namespace google {
+namespace protobuf {
+class MessageFactory;
+
+namespace python {
+
+// The (meta) type of all Messages classes.
+struct CMessageClass;
+
+struct PyMessageFactory {
+  PyObject_HEAD
+
+  // DynamicMessageFactory used to create C++ instances of messages.
+  // This object cache the descriptors that were used, so the DescriptorPool
+  // needs to get rid of it before it can delete itself.
+  //
+  // Note: A C++ MessageFactory is different from the PyMessageFactory.
+  // The C++ one creates messages, when the Python one creates classes.
+  MessageFactory* message_factory;
+
+  // borrowed reference to a Python DescriptorPool.
+  // TODO(amauryfa): invert the dependency: the MessageFactory owns the
+  // DescriptorPool, not the opposite.
+  PyDescriptorPool* pool;
+
+  // Make our own mapping to retrieve Python classes from C++ descriptors.
+  //
+  // Descriptor pointers stored here are owned by the DescriptorPool above.
+  // Python references to classes are owned by this PyDescriptorPool.
+  typedef hash_map<const Descriptor*, CMessageClass*> ClassesByMessageMap;
+  ClassesByMessageMap* classes_by_descriptor;
+};
+
+extern PyTypeObject PyMessageFactory_Type;
+
+namespace message_factory {
+
+// Creates a new MessageFactory instance.
+PyMessageFactory* NewMessageFactory(PyTypeObject* type, PyDescriptorPool* pool);
+
+// Registers a new Python class for the given message descriptor.
+// On error, returns -1 with a Python exception set.
+int RegisterMessageClass(PyMessageFactory* self,
+                         const Descriptor* message_descriptor,
+                         CMessageClass* message_class);
+// Retrieves the Python class registered with the given message descriptor, or
+// fail with a TypeError. Returns a *borrowed* reference.
+CMessageClass* GetMessageClass(PyMessageFactory* self,
+                               const Descriptor* message_descriptor);
+// Retrieves the Python class registered with the given message descriptor.
+// The class is created if not done yet. Returns a *new* reference.
+CMessageClass* GetOrCreateMessageClass(PyMessageFactory* self,
+                                       const Descriptor* message_descriptor);
+}  // namespace message_factory
+
+// Initialize objects used by this module.
+// On error, returns false with a Python exception set.
+bool InitMessageFactory();
+
+}  // namespace python
+}  // namespace protobuf
+
+}  // namespace google
+#endif  // GOOGLE_PROTOBUF_PYTHON_CPP_MESSAGE_FACTORY_H__