django-compression-middleware 0.4.0

Django middleware to compress responses using several algorithms.

This middleware implements compressed content encoding for HTTP. It is similar to Django’s GZipMiddleware (documentation), but additionally supports other compression methods. It is meant to be a drop-in replacement for Django’s GZipMiddleware. Its documentation — including security warnings — therefore apply here as well.

The middleware is focussed on the task of compressing typical Django responses such as HTML, JSON, etc. Both normal (bulk) and streaming responses are supported. For static file compression, have a look at other projects such as WhiteNoise.

Zstandard is a new method for compression with little client support so far. Most browsers now support Brotli compression (check support status on Can I use… Brotli). The middleware will choose the best compression method supported by the client as indicated in the request’s Accept-Encoding header. In order of preference:

• Zstandard (zstd)

• Brotli (br)

• gzip (gzip)

Summary of the project status:

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Installation and usage

The following requirements are supported and tested in all reasonable combinations:

• Python versions: 2.7, 3.4, 3.5, 3.6, 3.7, 3.8.

• Interpreters: CPython and PyPy.

• Django versions: 1.11 (LTS), 2.0, 2.1, 2.2 (LTS), 3.0.

pip install --upgrade django-compression-middleware

To apply compression to all the views served by Django, add compression_middleware.middleware.CompressionMiddleware to the MIDDLEWARE setting:

MIDDLEWARE = [
    # ...
    'compression_middleware.middleware.CompressionMiddleware',
    # ...
]

Remove GZipMiddleware and BrotliMiddleware if you used it before. Consult the Django documentation on the correct ordering of middleware.

Alternatively you can decorate views individually to serve them with compression:

from compression_middleware.decorators import compress_page

@compress_page
def index_view(request):
    ...

If you use the middleware, you can decorate views individually to disable compression:

from compression_middleware.decorators import nocompress_page

@nocompress_page
def pdf_view(request):
    ...

This will mark the response as having a content encoding of identity, i.e. no compression. Even without the middleware, this might be useful to indicate to intermediaries that no compression should be attempted for a particular response.

Note that your browser might not send the br entry in the Accept-Encoding header when you test without HTTPS (common on localhost). You can force it to send the header, though. In Firefox, visit about:config and set network.http.accept-encoding to indicate support. Note that you might encounter some problems on the web with such a setting (which is why Brotli is only supported on secure connections by default).

Credits and Resources

The code and tests in this project are based on Django’s GZipMiddleware and Vašek Dohnal’s django-brotli. For compression, it uses the following modules to bind to fast C modules:

• The zstandard bindings. It supports both a C module (for CPython) and CFFI which should be appropriate for PyPy. See the documentation for full details.

• The Brotli bindings or brotlipy. The latter is preferred on PyPy since it is implemented using cffi. But both should work on both Python implementations.

• Python’s builtin gzip module.

Further readding on Wikipedia:

• HTTP compression

• Zstandard

• Brotli

• gzip

Contributing

1. Clone this repository (git clone ...)

2. Create a virtualenv

3. Install package dependencies: pip install --upgrade -r requirements_dev.txt

4. Change some code

5. Run the tests: in the project root simply execute pytest, and afterwards preferably tox to test the full test matrix. Consider installing as many supported interpreters as possible (having them in your PATH is often sufficient).

6. Submit a pull request and check for any errors reported by the Continuous Integration service.

License

The MPL 2.0 License

Copyright (c) 2019-2020 Friedel Wolff.