diff options
Diffstat (limited to 'generator/google/protobuf/internal/api_implementation.py')
| -rw-r--r-- | generator/google/protobuf/internal/api_implementation.py | 84 |
1 files changed, 29 insertions, 55 deletions
diff --git a/generator/google/protobuf/internal/api_implementation.py b/generator/google/protobuf/internal/api_implementation.py index 460a4a6..ce02a32 100644 --- a/generator/google/protobuf/internal/api_implementation.py +++ b/generator/google/protobuf/internal/api_implementation.py @@ -1,6 +1,6 @@ # Protocol Buffers - Google's data interchange format # Copyright 2008 Google Inc. All rights reserved. -# https://developers.google.com/protocol-buffers/ +# 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 @@ -28,78 +28,53 @@ # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. -"""Determine which implementation of the protobuf API is used in this process. +""" +This module is the central entity that determines which implementation of the +API is used. """ -import os -import warnings -import sys - -try: - # pylint: disable=g-import-not-at-top - from google.protobuf.internal import _api_implementation - # The compile-time constants in the _api_implementation module can be used to - # switch to a certain implementation of the Python API at build time. - _api_version = _api_implementation.api_version - _proto_extension_modules_exist_in_build = True -except ImportError: - _api_version = -1 # Unspecified by compiler flags. - _proto_extension_modules_exist_in_build = False - -if _api_version == 1: - raise ValueError('api_version=1 is no longer supported.') -if _api_version < 0: # Still unspecified? - try: - # The presence of this module in a build allows the proto implementation to - # be upgraded merely via build deps rather than a compiler flag or the - # runtime environment variable. - # pylint: disable=g-import-not-at-top - from google.protobuf import _use_fast_cpp_protos - # Work around a known issue in the classic bootstrap .par import hook. - if not _use_fast_cpp_protos: - raise ImportError('_use_fast_cpp_protos import succeeded but was None') - del _use_fast_cpp_protos - _api_version = 2 - except ImportError: - if _proto_extension_modules_exist_in_build: - if sys.version_info[0] >= 3: # Python 3 defaults to C++ impl v2. - _api_version = 2 - # TODO(b/17427486): Make Python 2 default to C++ impl v2. - -_default_implementation_type = ( - 'python' if _api_version <= 0 else 'cpp') +__author__ = 'petar@google.com (Petar Petrov)' +import os # This environment variable can be used to switch to a certain implementation -# of the Python API, overriding the compile-time constants in the -# _api_implementation module. Right now only 'python' and 'cpp' are valid -# values. Any other value will be ignored. +# of the Python API. Right now only 'python' and 'cpp' are valid values. Any +# other value will be ignored. _implementation_type = os.getenv('PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION', - _default_implementation_type) + 'python') + if _implementation_type != 'python': + # For now, by default use the pure-Python implementation. + # The code below checks if the C extension is available and + # uses it if it is available. _implementation_type = 'cpp' + ## Determine automatically which implementation to use. + #try: + # from google.protobuf.internal import cpp_message + # _implementation_type = 'cpp' + #except ImportError, e: + # _implementation_type = 'python' -if 'PyPy' in sys.version and _implementation_type == 'cpp': - warnings.warn('PyPy does not work yet with cpp protocol buffers. ' - 'Falling back to the python implementation.') - _implementation_type = 'python' # This environment variable can be used to switch between the two -# 'cpp' implementations, overriding the compile-time constants in the -# _api_implementation module. Right now only '2' is supported. Any other -# value will cause an error to be raised. +# 'cpp' implementations. Right now only 1 and 2 are valid values. Any +# other value will be ignored. _implementation_version_str = os.getenv( - 'PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION_VERSION', '2') + 'PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION_VERSION', + '1') + -if _implementation_version_str != '2': +if _implementation_version_str not in ('1', '2'): raise ValueError( - 'unsupported PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION_VERSION: "' + - _implementation_version_str + '" (supported versions: 2)' + "unsupported PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION_VERSION: '" + + _implementation_version_str + "' (supported versions: 1, 2)" ) + _implementation_version = int(_implementation_version_str) + # Usage of this function is discouraged. Clients shouldn't care which # implementation of the API is in use. Note that there is no guarantee # that differences between APIs will be maintained. @@ -107,7 +82,6 @@ _implementation_version = int(_implementation_version_str) def Type(): return _implementation_type - # See comment on 'Type' above. def Version(): return _implementation_version |