[Django] Ease disabling gzip support

[hartwork]

Hi!

I'm very happy I ran into WhiteNoise, happy user, thanks for sharing it as software libre.
I started using brotli (with brotli_static on;) at some point and noticed that compressing all the files with both gzip and brotli takes a few seconds. So I played with getting rid of gzip compression like this:

# Copyright (c) 2018 Sebastian Pipping
# Copyright (c) 2013 David Evans
# License under the MIT license

from django.conf import settings
from whitenoise.compress import Compressor
from whitenoise.storage import CompressedManifestStaticFilesStorage


class WhiteNoiseWithoutGzipStorage(CompressedManifestStaticFilesStorage):

    def create_compressor(self, extensions):
        return Compressor(extensions=extensions, quiet=True, use_gzip=False)

    def compress_files(self, names):
        extensions = getattr(settings,
                             'WHITENOISE_SKIP_COMPRESS_EXTENSIONS', None)
        compressor = self.create_compressor(extensions)
        for name in names:
            if compressor.should_compress(name):
                path = self.path(name)
                prefix_len = len(path) - len(name)
                for compressed_path in compressor.compress(path):
                    compressed_name = compressed_path[prefix_len:]
                    yield name, compressed_name

(and then STATICFILES_STORAGE = 'foo.bar.storage.WhiteNoiseWithoutGzipStorage' in settings to activate, for completeness)

As you can see, to make that work, I currently need to duplicate 100% of CompressedManifestStaticFilesStorage.compress_files, which is not ideal.

So I wonder about how to best ease that case. One way would be to extract a new public-API method create_compressor similar to the one above, except without use_gzip=False. Would you except a pull request in that direction? Would you want to do it yourself? Other ideas?

Thanks and best, Sebastian

[edmorley]

Hi :-)

In #148 I found that Brotli took 95%+ of the total time to compress, so disabling gzip probably wouldn't help reduce the duration by much. Instead concurrency is likely the best way forwards - I keep meaning to find time to dust off the WIP I have locally.

[hartwork]

Hi! Good analysis at #148. I think we can have both at the same time: Getting wanted things faster (Brotli) and unwanted things (gzip for me) not be done at all.

[hartwork]

With #208 merged and with WhiteNoise 4.1.2 around the above code can now be simplified to:

# Copyright (c) 2018 Sebastian Pipping
# License under the MIT license

from whitenoise.compress import Compressor
from whitenoise.storage import CompressedManifestStaticFilesStorage


class WhiteNoiseWithoutGzipStorage(CompressedManifestStaticFilesStorage):

    def create_compressor(self, **kwargs):
        kwargs['use_gzip'] = False
        return Compressor(**kwargs)

Closing, "bug" fixed in my eyes. Thanks again!