Add example project showing how to use BrotliCFFI

Author: sethmlarson

README.rst

@@ -17,6 +17,19 @@ More information can be found `in the documentation`_.
 .. _available here: https://github.com/google/brotli
 .. _in the documentation: https://brotlipy.readthedocs.org
 
+Using BrotliCFFI in Projects
+----------------------------
+
+The API is 100% compatible with the `Brotli Python C bindings`_.
+We recommend installing the C bindings on CPython and the CFFI
+bindings everywhere else (PyPy, etc)
+
+We provide an `example project`_ that shows how to use both
+libraries together to support Brotli with multiple Python implementations.
+
+.. _Brotli Python C bindings: https://pypi.org/project/Brotli
+.. _example project: https://github.com/python-hyper/brotlipy/tree/master/example
+
 License
 -------
 

example/README.md

@@ -0,0 +1,120 @@
+# Example Project using C and CFFI Brotli Bindings
+
+This simple example project shows how to include
+`brotlicffi` into projects supporting both CPython
+and other Python implementations like PyPy.
+
+Basically it boils down to these two steps:
+
+Include the two dependencies in your `install_requires`/`requirements.txt`:
+
+```python
+# install_requires:
+from setuptools import setup
+
+setup(
+    ...,
+    install_requires=[
+        "brotli; implementation_name == 'cpython'",
+        "brotlicffi; implementation_name != 'cpython'"
+    ]
+)
+```
+
+```
+# requirements.txt:
+brotli; implementation_name == 'cpython'
+brotlicffi; implementation_name != 'cpython'
+```
+
+...then you can import the bindings in your project like so:
+
+```python
+try:
+    import brotlicffi as brotli
+except ImportError:
+    import brotli
+```
+
+It should be that simple! Now let's see our example project in action:
+
+## Installing on CPython and PyPy
+
+Build the project sdist locally
+
+```
+$ cd example/
+$ python setup.py sdist
+$ ls dist/
+example-brotli-project-0.1.0.tar.gz
+```
+
+### Installing on CPython
+
+Run `python:3.7-slim` Docker image to test against CPython
+
+```
+$ docker run --rm -it -v $(pwd)/dist:/dist python:3.7-slim /bin/bash
+```
+
+Install the example project
+
+```
+$ python -m pip install /dist/example-brotli-project-0.1.0.tar.gz
+Processing /dist/example-brotli-project-0.1.0.tar.gz
+Collecting brotli
+  Downloading Brotli-1.0.9-cp37-cp37-manylinux1_x86_64.whl (357 kB)
+     |████████████████████████████████| 357 kB 1.9 MB/s 
+Building wheels for collected packages: example-brotli-project
+  Building wheel for example-brotli-project (setup.py) ... done
+  Created wheel for example-brotli-project: filename=example_brotli_project-0.1.0-py3-none-any.whl size=1976 sha256=b94975444c08cf82f395c8277e29b5b6f3b3270dd4f7d224482e4493be89c6bd
+  Stored in directory: /root/.cache/pip/wheels/be/67/36/911a88789436560de345984e6c4c3785098e98b92dcbab5980
+Successfully built example-brotli-project
+Installing collected packages: brotli, example-brotli-project
+Successfully installed brotli-1.0.9 example-brotli-project-0.1.0
+```
+
+Notice that `Brotli` is installed from PyPI instead of `brotlicffi` on CPython.
+
+Now run the program and see the output:
+
+```
+$ example-brotli-project "Hello, world!"
+Compressing data: b'Hello, world!'
+Compressed data: b'\x0b\x06\x80Hello, world!\x03'
+Decompressed data: b'Hello, world!'
+```
+
+### Installing on PyPy
+
+Run `pypy:3.7-slim` Docker image to test against PyPy
+
+```
+$ docker run --rm -it -v $(pwd)/dist:/dist pypy:3.7-slim /bin/bash
+$ pypy -m pip install /dist/example-brotli-project-0.1.0.tar.gz
+Processing /dist/example-brotli-project-0.1.0.tar.gz
+Collecting brotlicffi
+  Downloading brotlicffi-0.8.0-pp37-pypy37_pp73-manylinux1_x86_64.whl (341 kB)
+     |████████████████████████████████| 341 kB 2.8 MB/s 
+Requirement already satisfied: cffi>=1.0.0 in /opt/pypy/lib_pypy (from brotlicffi->example-brotli-project==0.1.0) (1.14.2)
+Building wheels for collected packages: example-brotli-project
+  Building wheel for example-brotli-project (setup.py) ... done
+  Created wheel for example-brotli-project: filename=example_brotli_project-0.1.0-py3-none-any.whl size=1976 sha256=566f5bfb3a0d74d11485b02b929a09d6e6cc8bab7c409cf30ff50f2067692356
+  Stored in directory: /root/.cache/pip/wheels/cb/e1/0f/337346ea74252e5b652824bb0f2fc82e81208f9f8e3de42465
+Successfully built example-brotli-project
+Installing collected packages: brotlicffi, example-brotli-project
+Successfully installed brotlicffi-0.8.0 example-brotli-project-0.1.0
+```
+
+Notice now that `brotlicffi` is installed from PyPI instead of `Brotli` on CPython.
+
+Now run the program and see the output:
+
+```
+$ example-brotli-project "Hello, world!"
+Compressing data: b'Hello, world!'
+Compressed data: b'\x0b\x06\x80Hello, world!\x03'
+Decompressed data: b'Hello, world!'
+```
+
+Identical output compared to CPython! :tada:

example/example_brotli_project.py

@@ -0,0 +1,27 @@
+"""A simple project that is compatible with both
+'brotli' C bindings and 'brotlicffi' CFFI bindings
+"""
+
+import sys
+
+try:
+    import brotlicffi as brotli
+except ImportError:
+    import brotli
+
+
+def main():
+    data = sys.argv[1].encode("utf-8")
+    print(f"Compressing data: {data}")
+
+    compressor = brotli.Compressor(mode=brotli.MODE_TEXT)
+    compressed = compressor.process(data) + compressor.finish()
+    print(f"Compressed data: {compressed}")
+
+    decompressor = brotli.Decompressor()
+    decompressed = decompressor.process(compressed) + decompressor.finish()
+    print(f"Decompressed data: {decompressed}")
+
+
+if __name__ == "__main__":
+    main()

example/setup.py

@@ -0,0 +1,17 @@
+from setuptools import setup
+
+
+setup(
+    name="example-brotli-project",
+    version="0.1.0",
+    py_modules=["example_brotli_project"],
+    install_requires=[
+        "brotli; implementation_name == 'cpython'",
+        "brotlicffi; implementation_name != 'cpython'"
+    ],
+    entry_points={
+        "console_scripts": [
+            "example-brotli-project=example_brotli_project:main"
+        ]
+    }
+)