liujisi@google.com | 33165fe | 2010-11-02 13:14:58 +0000 | [diff] [blame^] | 1 | # Protocol Buffers - Google's data interchange format |
| 2 | # Copyright 2008 Google Inc. All rights reserved. |
| 3 | # http://code.google.com/p/protobuf/ |
| 4 | # |
| 5 | # Redistribution and use in source and binary forms, with or without |
| 6 | # modification, are permitted provided that the following conditions are |
| 7 | # met: |
| 8 | # |
| 9 | # * Redistributions of source code must retain the above copyright |
| 10 | # notice, this list of conditions and the following disclaimer. |
| 11 | # * Redistributions in binary form must reproduce the above |
| 12 | # copyright notice, this list of conditions and the following disclaimer |
| 13 | # in the documentation and/or other materials provided with the |
| 14 | # distribution. |
| 15 | # * Neither the name of Google Inc. nor the names of its |
| 16 | # contributors may be used to endorse or promote products derived from |
| 17 | # this software without specific prior written permission. |
| 18 | # |
| 19 | # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 20 | # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 21 | # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 22 | # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 23 | # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 24 | # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| 25 | # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 26 | # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 27 | # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 28 | # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| 29 | # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 30 | |
| 31 | """ |
| 32 | This module is the central entity that determines which implementation of the |
| 33 | API is used. |
| 34 | """ |
| 35 | |
| 36 | __author__ = 'petar@google.com (Petar Petrov)' |
| 37 | |
| 38 | import os |
| 39 | # This environment variable can be used to switch to a certain implementation |
| 40 | # of the Python API. Right now only 'python' and 'cpp' are valid values. Any |
| 41 | # other value will be ignored. |
| 42 | _implementation_type = os.getenv('PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION', |
| 43 | 'python') |
| 44 | |
| 45 | |
| 46 | if _implementation_type != 'python': |
| 47 | # For now, by default use the pure-Python implementation. |
| 48 | # The code below checks if the C extension is available and |
| 49 | # uses it if it is available. |
| 50 | _implementation_type = 'cpp' |
| 51 | ## Determine automatically which implementation to use. |
| 52 | #try: |
| 53 | # from google.protobuf.internal import cpp_message |
| 54 | # _implementation_type = 'cpp' |
| 55 | #except ImportError, e: |
| 56 | # _implementation_type = 'python' |
| 57 | |
| 58 | |
| 59 | # Usage of this function is discouraged. Clients shouldn't care which |
| 60 | # implementation of the API is in use. Note that there is no guarantee |
| 61 | # that differences between APIs will be maintained. |
| 62 | # Please don't use this function if possible. |
| 63 | def Type(): |
| 64 | return _implementation_type |