101 lines
3.5 KiB
Plaintext
101 lines
3.5 KiB
Plaintext
Protocol Buffers - Google's data interchange format
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Copyright 2008 Google Inc.
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This directory contains the Python Protocol Buffers runtime library.
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Normally, this directory comes as part of the protobuf package, available
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from:
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http://code.google.com/p/protobuf
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The complete package includes the C++ source code, which includes the
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Protocol Compiler (protoc). If you downloaded this package from PyPI
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or some other Python-specific source, you may have received only the
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Python part of the code. In this case, you will need to obtain the
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Protocol Compiler from some other source before you can use this
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package.
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Development Warning
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===================
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The Python implementation of Protocol Buffers is not as mature as the C++
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and Java implementations. It may be more buggy, and it is known to be
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pretty slow at this time. If you would like to help fix these issues,
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join the Protocol Buffers discussion list and let us know!
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Installation
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============
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1) Make sure you have Python 2.4 or newer. If in doubt, run:
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$ python -V
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2) If you do not have setuptools installed, note that it will be
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downloaded and installed automatically as soon as you run setup.py.
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If you would rather install it manually, you may do so by following
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the instructions on this page:
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http://peak.telecommunity.com/DevCenter/EasyInstall#installation-instructions
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3) Build the C++ code, or install a binary distribution of protoc. If
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you install a binary distribution, make sure that it is the same
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version as this package. If in doubt, run:
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$ protoc --version
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4) Run the tests:
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$ python setup.py test
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If some tests fail, this library may not work correctly on your
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system. Continue at your own risk.
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Please note that there is a known problem with some versions of
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Python on Cygwin which causes the tests to fail after printing the
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error: "sem_init: Resource temporarily unavailable". This appears
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to be a bug either in Cygwin or in Python:
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http://www.cygwin.com/ml/cygwin/2005-07/msg01378.html
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We do not know if or when it might me fixed. We also do not know
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how likely it is that this bug will affect users in practice.
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5) Install:
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$ python setup.py install
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This step may require superuser privileges.
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NOTE: To use C++ implementation, you need to install C++ protobuf runtime
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library of the same version and export the environment variable before this
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step. See the "C++ Implementation" section below for more details.
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Usage
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=====
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The complete documentation for Protocol Buffers is available via the
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web at:
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http://code.google.com/apis/protocolbuffers/
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C++ Implementation
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==================
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WARNING: This is EXPERIMENTAL and only available for CPython platforms.
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The C++ implementation for Python messages is built as a Python extension to
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improve the overall protobuf Python performance.
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To use the C++ implementation, you need to:
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1) Install the C++ protobuf runtime library, please see instructions in the
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parent directory.
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2) Export an environment variable:
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$ export PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION=cpp
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You need to export this variable before running setup.py script to build and
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install the extension. You must also set the variable at runtime, otherwise
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the pure-Python implementation will be used. In a future release, we will
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change the default so that C++ implementation is used whenever it is available.
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It is strongly recommended to run `python setup.py test` after setting the
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variable to "cpp", so the tests will be against C++ implemented Python
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messages.
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