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Diffstat (limited to 'third_party/protobuf/3.4.0/python/google/protobuf/internal/api_implementation.py')
-rwxr-xr-x | third_party/protobuf/3.4.0/python/google/protobuf/internal/api_implementation.py | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/third_party/protobuf/3.4.0/python/google/protobuf/internal/api_implementation.py b/third_party/protobuf/3.4.0/python/google/protobuf/internal/api_implementation.py new file mode 100755 index 0000000000..422af5902d --- /dev/null +++ b/third_party/protobuf/3.4.0/python/google/protobuf/internal/api_implementation.py @@ -0,0 +1,139 @@ +# 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. + +"""Determine which implementation of the protobuf API is used in this process. +""" + +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') + +# 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. +_implementation_type = os.getenv('PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION', + _default_implementation_type) + +if _implementation_type != 'python': + _implementation_type = 'cpp' + +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. +_implementation_version_str = os.getenv( + 'PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION_VERSION', '2') + +if _implementation_version_str != '2': + raise ValueError( + 'unsupported PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION_VERSION: "' + + _implementation_version_str + '" (supported versions: 2)' + ) + +_implementation_version = int(_implementation_version_str) + + +# Detect if serialization should be deterministic by default +try: + # The presence of this module in a build allows the proto implementation to + # be upgraded merely via build deps. + # + # NOTE: Merely importing this automatically enables deterministic proto + # serialization for C++ code, but we still need to export it as a boolean so + # that we can do the same for `_implementation_type == 'python'`. + # + # NOTE2: It is possible for C++ code to enable deterministic serialization by + # default _without_ affecting Python code, if the C++ implementation is not in + # use by this module. That is intended behavior, so we don't actually expose + # this boolean outside of this module. + # + # pylint: disable=g-import-not-at-top,unused-import + from google.protobuf import enable_deterministic_proto_serialization + _python_deterministic_proto_serialization = True +except ImportError: + _python_deterministic_proto_serialization = False + + +# 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. +# Please don't use this function if possible. +def Type(): + return _implementation_type + + +# See comment on 'Type' above. +def Version(): + return _implementation_version + + +# For internal use only +def IsPythonDefaultSerializationDeterministic(): + return _python_deterministic_proto_serialization |