| // 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. |
| |
| // This file can be included by other C++ libraries, typically extension modules |
| // which want to interact with the Python Messages coming from the "cpp" |
| // implementation of protocol buffers. |
| // |
| // Usage: |
| // Declare a (probably static) variable to hold the API: |
| // const PyProto_API* py_proto_api; |
| // In some initialization function, write: |
| // py_proto_api = static_cast<const PyProto_API*>(PyCapsule_Import( |
| // PyProtoAPICapsuleName(), 0)); |
| // if (!py_proto_api) { ...handle ImportError... } |
| // Then use the methods of the returned class: |
| // py_proto_api->GetMessagePointer(...); |
| |
| #ifndef GOOGLE_PROTOBUF_PYTHON_PROTO_API_H__ |
| #define GOOGLE_PROTOBUF_PYTHON_PROTO_API_H__ |
| |
| #include <Python.h> |
| |
| #include <google/protobuf/descriptor_database.h> |
| #include <google/protobuf/message.h> |
| |
| namespace google { |
| namespace protobuf { |
| namespace python { |
| |
| // Note on the implementation: |
| // This API is designed after |
| // https://docs.python.org/3/extending/extending.html#providing-a-c-api-for-an-extension-module |
| // The class below contains no mutable state, and all methods are "const"; |
| // we use a C++ class instead of a C struct with functions pointers just because |
| // the code looks more readable. |
| struct PyProto_API { |
| // The API object is created at initialization time and never freed. |
| // This destructor is never called. |
| virtual ~PyProto_API() {} |
| |
| // Operations on Messages. |
| |
| // If the passed object is a Python Message, returns its internal pointer. |
| // Otherwise, returns NULL with an exception set. |
| virtual const Message* GetMessagePointer(PyObject* msg) const = 0; |
| |
| // If the passed object is a Python Message, returns a mutable pointer. |
| // Otherwise, returns NULL with an exception set. |
| // This function will succeed only if there are no other Python objects |
| // pointing to the message, like submessages or repeated containers. |
| // With the current implementation, only empty messages are in this case. |
| virtual Message* GetMutableMessagePointer(PyObject* msg) const = 0; |
| |
| // Expose the underlying DescriptorPool and MessageFactory to enable C++ code |
| // to create Python-compatible message. |
| virtual const DescriptorPool* GetDefaultDescriptorPool() const = 0; |
| virtual MessageFactory* GetDefaultMessageFactory() const = 0; |
| }; |
| |
| inline const char* PyProtoAPICapsuleName() { |
| static const char kCapsuleName[] = |
| "google.protobuf.pyext._message.proto_API"; |
| return kCapsuleName; |
| } |
| |
| } // namespace python |
| } // namespace protobuf |
| } // namespace google |
| |
| #endif // GOOGLE_PROTOBUF_PYTHON_PROTO_API_H__ |