Squashed 'third_party/protobuf/' content from commit e35e248
Change-Id: I6cbe123d09fe50fdcad0e51466665daeee7433c7
git-subtree-dir: third_party/protobuf
git-subtree-split: e35e24800fb8d694bdeea5fd63dc7d1b14d68723
diff --git a/python/google/protobuf/internal/api_implementation.py b/python/google/protobuf/internal/api_implementation.py
new file mode 100755
index 0000000..ffcf751
--- /dev/null
+++ b/python/google/protobuf/internal/api_implementation.py
@@ -0,0 +1,107 @@
+# 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 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'
+
+# 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)
+
+
+# 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