131 lines
3.8 KiB
Markdown
131 lines
3.8 KiB
Markdown
Protocol Buffers - Google's data interchange format
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===================================================
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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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https://developers.google.com/protocol-buffers/
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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 pure python performance is slow. For better performance please
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use python c++ implementation.
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Installation
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============
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1) Make sure you have Python 3.7 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](https://packaging.python.org/en/latest/installing.html#setup-for-installing-packages).
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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) Build and run the tests:
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$ python setup.py build
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$ python setup.py test
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To build, test, and use the C++ implementation, you must first compile
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`libprotobuf.so`:
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$ (cd .. && make)
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On OS X:
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If you are running a Homebrew-provided Python, you must make sure another
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version of protobuf is not already installed, as Homebrew's Python will
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search `/usr/local/lib` for `libprotobuf.so` before it searches
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`../src/.libs`.
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You can either unlink Homebrew's protobuf or install the `libprotobuf` you
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built earlier:
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$ brew unlink protobuf
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or
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$ (cd .. && make install)
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On other *nix:
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You must make `libprotobuf.so` dynamically available. You can either
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install libprotobuf you built earlier, or set `LD_LIBRARY_PATH`:
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$ export LD_LIBRARY_PATH=../src/.libs
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or
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$ (cd .. && make install)
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To build the C++ implementation run:
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$ python setup.py build --cpp_implementation
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Then run the tests like so:
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$ python setup.py test --cpp_implementation
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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
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Python](http://www.cygwin.com/ml/cygwin/2005-07/msg01378.html).
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We do not know if or when it might be 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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or:
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$ (cd .. && make install)
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$ python setup.py install --cpp_implementation
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This step may require superuser privileges.
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NOTE: To use C++ implementation, you need to export an environment
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variable before running your program. See the "C++ Implementation"
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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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https://developers.google.com/protocol-buffers/
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C++ Implementation
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==================
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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 install the C++ protobuf runtime
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library, please see instructions in the parent directory.
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