Protocol buffer code generation (protobuf)

Description

The protobuf module supports code generation for protocol buffers.

To use the module in inline code generation import it by:

cogeno.import_module('protobuf')

In case you want to use the protobuf module in another Python project import it by:

import cogeno.modules.protobuf

Cogeno invocation options

--protobuf:db-dir DIR

Write or read protocol buffer code databases to/ from DIR.

--protobuf:sources FILE [FILE ...]

The *.proto source FILE(s) to generate the protocol buffer code for.

--protobuf:include-dirs DIR [DIR ...]

Search for *.proto import files in the protocol buffer include DIR(s).

Code generation functions

cogeno.modules.protobuf.proto_gen(generator='nanopb', force_generate=False)

Get protocol buffer code prepared for cogeno use.

Return

Protocol buffer code database

Parameters

  • generator: The protocol buffer generator to use to generate the protocol buffer code. One of ‘nanopb’, ‘pbtools’, ‘protobluff’, ‘cpp’, ‘python’. Default is ‘nanopb’.

  • force_generate: Force generation of the protocol buffer code, even if already generated. Default is False.

Generate code with protobuf

Protocol buffers are a language-neutral, platform-neutral extensible mechanism for serializing structured data. There exist several implementations for a lot of programming languages.

The protobuf module supports the following code generators:

Language

Generator

C

nanopb

C

pbtools

C

protobluff

C++

cpp

Python

python

The protocol buffer code that is generated by a generator is added to the protocol buffer code database.

cogeno.modules.protobuf.ProtoCodeDb : public MutableMapping

Protocol buffers code database.

All generated code is cached in dictionary.

Usage: 

cogeno.module_import('protobuf')
db = protobuf.protodb("nanopb")
db2 = protobuf.protodb("py")
cogeno.out(db['my_message.pb.h'])
cogeno.out(db('pb_encode.c'])

Public Functions

__init__(self, generator=None, sources=None, include_dirs=None, dst_dir=None)

Initialize protocol buffer code database.

Parameters

  • generator: Any of ‘nonopb’, …

  • sources: *.proto sources

  • include_dirs: Directories to search for *.proto import

  • dst_dir: Destination directory for generated code

__getitem__(self, key)
__setitem__(self, key, value)
__delitem__(self, key)
__iter__(self)
__len__(self)
add_sources(self, sources)

Add sources to the list of sources for generation.

Return

True in case new sources were added, False otherwise.

Parameters

  • sources: List of source file pathes

add_include_dirs(self, include_dirs)

Add include directories to the list for generation.

Return

True in case new include dirs were added, False otherwise.

Parameters

  • include_dirs: List of include dir pathes

load(self)

Load generated code into database.

generate(self)

Generate protocol buffer code.

Note

This routine will use grpcio-provided protoc if it exists, and is using the system-installed protoc as a fallback.

Return

protoc invocation return value

Public Static Functions

protoc_gen_nanopb_path()
has_grpcio_protoc()

Check if grpcio-tools protoc is installed.

Return

True if installed, False otherwise

Generate protobuf code using protobluff

There is no uptodate PyPI package available for protobluff. The protobluff plugin for protoc has to be build and installed from source as described in the protobluff documentation. The source code is available on GitHub.

On Ubuntu you might use this script (setup_protobluff.sh):

#! /usr/bin/env sh
# Install protobluff to user local

# Ubuntu
sudo apt install git gcc automake libtool protobuf-compiler libprotoc-dev libprotobuf-dev check

# get the sources
git clone https://github.com/squidfunk/protobluff protobluff.git
cd protobluff.git

# configure
./autogen.sh
./configure --prefix ${HOME}/.local

# build & test & install to user dir
make
make test
make install

# remove the git repository
cd ..
rm -rf protobluff.git

The protobuf module searches the pathes defined in the environment for protoc-gen-protobluff.