python/google/protobuf/pyext/message_module.cc

// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc.  All rights reserved.
// https://developers.google.com/protocol-buffers/
//
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// 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
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// 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.

#include <Python.h>

#include <google/protobuf/message_lite.h>
#include <google/protobuf/pyext/descriptor.h>
#include <google/protobuf/pyext/descriptor_pool.h>
#include <google/protobuf/pyext/message.h>
#include <google/protobuf/pyext/message_factory.h>
#include <google/protobuf/proto_api.h>

namespace {

// C++ API.  Clients get at this via proto_api.h
struct ApiImplementation : google::protobuf::python::PyProto_API {
  const google::protobuf::Message* GetMessagePointer(PyObject* msg) const override {
    return google::protobuf::python::PyMessage_GetMessagePointer(msg);
  }
  google::protobuf::Message* GetMutableMessagePointer(PyObject* msg) const override {
    return google::protobuf::python::PyMessage_GetMutableMessagePointer(msg);
  }
  const google::protobuf::Descriptor* MessageDescriptor_AsDescriptor(
      PyObject* desc) const override {
    return google::protobuf::python::PyMessageDescriptor_AsDescriptor(desc);
  }
  const google::protobuf::EnumDescriptor* EnumDescriptor_AsDescriptor(
      PyObject* enum_desc) const override {
    return google::protobuf::python::PyEnumDescriptor_AsDescriptor(enum_desc);
  }

  const google::protobuf::DescriptorPool* GetDefaultDescriptorPool() const override {
    return google::protobuf::python::GetDefaultDescriptorPool()->pool;
  }

  google::protobuf::MessageFactory* GetDefaultMessageFactory() const override {
    return google::protobuf::python::GetDefaultDescriptorPool()
        ->py_message_factory->message_factory;
  }
  PyObject* NewMessage(const google::protobuf::Descriptor* descriptor,
                       PyObject* py_message_factory) const override {
    return google::protobuf::python::PyMessage_New(descriptor, py_message_factory);
  }
  PyObject* NewMessageOwnedExternally(
      google::protobuf::Message* msg, PyObject* py_message_factory) const override {
    return google::protobuf::python::PyMessage_NewMessageOwnedExternally(
        msg, py_message_factory);
  }
  PyObject* DescriptorPool_FromPool(
      const google::protobuf::DescriptorPool* pool) const override {
    return google::protobuf::python::PyDescriptorPool_FromPool(pool);
  }
};

}  // namespace

static const char module_docstring[] =
    "python-proto2 is a module that can be used to enhance proto2 Python API\n"
    "performance.\n"
    "\n"
    "It provides access to the protocol buffers C++ reflection API that\n"
    "implements the basic protocol buffer functions.";

static PyMethodDef ModuleMethods[] = {
    {"SetAllowOversizeProtos",
     (PyCFunction)google::protobuf::python::cmessage::SetAllowOversizeProtos, METH_O,
     "Enable/disable oversize proto parsing."},
    // DO NOT USE: For migration and testing only.
    {NULL, NULL}};

#if PY_MAJOR_VERSION >= 3
static struct PyModuleDef _module = {PyModuleDef_HEAD_INIT,
                                     "_message",
                                     module_docstring,
                                     -1,
                                     ModuleMethods, /* m_methods */
                                     NULL,
                                     NULL,
                                     NULL,
                                     NULL};
#define INITFUNC PyInit__message
#define INITFUNC_ERRORVAL NULL
#else  // Python 2
#define INITFUNC init_message
#define INITFUNC_ERRORVAL
#endif

PyMODINIT_FUNC INITFUNC() {
  PyObject* m;
#if PY_MAJOR_VERSION >= 3
  m = PyModule_Create(&_module);
#else
  m = Py_InitModule3("_message", ModuleMethods, module_docstring);
#endif
  if (m == NULL) {
    return INITFUNC_ERRORVAL;
  }

  if (!google::protobuf::python::InitProto2MessageModule(m)) {
    Py_DECREF(m);
    return INITFUNC_ERRORVAL;
  }

  // Adds the C++ API
  if (PyObject* api = PyCapsule_New(
          new ApiImplementation(), google::protobuf::python::PyProtoAPICapsuleName(),
          [](PyObject* o) {
            delete (ApiImplementation*)PyCapsule_GetPointer(
                o, google::protobuf::python::PyProtoAPICapsuleName());
          })) {
    PyModule_AddObject(m, "proto_API", api);
  } else {
    return INITFUNC_ERRORVAL;
  }

#if PY_MAJOR_VERSION >= 3
  return m;
#endif
}