Add deflate compression algorithm

README.md

@@ -5,7 +5,7 @@
 [![Coverage](https://coveralls.io/repos/libwilliam/flask-compress/badge.svg)](https://coveralls.io/github/libwilliam/flask-compress)
 [![License](https://img.shields.io/pypi/l/flask-compress.svg)](https://github.com/libwilliam/flask-compress/blob/master/LICENSE.txt)
 
-Flask-Compress allows you to easily compress your [Flask](http://flask.pocoo.org/) application's responses with gzip.
+Flask-Compress allows you to easily compress your [Flask](http://flask.pocoo.org/) application's responses with gzip, deflate or brotli.
 
 The preferred solution is to have a server (like [Nginx](http://wiki.nginx.org/Main)) automatically compress the static files for you. If you don't have that option Flask-Compress will solve the problem for you.
 
@@ -49,7 +49,7 @@ $ easy_install flask-compress
 
 ## Using Flask-Compress
 
-Flask-Compress is incredibly simple to use. In order to start gzip'ing your Flask application's assets, the first thing to do is let Flask-Compress know about your [`flask.Flask`](http://flask.pocoo.org/docs/latest/api/#flask.Flask) application object.
+Flask-Compress is incredibly simple to use. In order to start compressing your Flask application's assets, the first thing to do is let Flask-Compress know about your [`flask.Flask`](http://flask.pocoo.org/docs/latest/api/#flask.Flask) application object.
 
 ```python
 from flask import Flask
@@ -73,7 +73,7 @@ def start_app():
     return app
 ```
 
-In terms of automatically compressing your assets using gzip, passing your [`flask.Flask`](http://flask.pocoo.org/docs/latest/api/#flask.Flask) object to the `flask_compress.Compress` object is all that needs to be done.
+In terms of automatically compressing your assets, passing your [`flask.Flask`](http://flask.pocoo.org/docs/latest/api/#flask.Flask) object to the `flask_compress.Compress` object is all that needs to be done.
 
 
 ## Options
@@ -84,11 +84,12 @@ Within your Flask application's settings you can provide the following settings
 | ------ | ----------- | ------- |
 | `COMPRESS_MIMETYPES` | Set the list of mimetypes to compress here. | `[`<br>`'text/html',`<br>`'text/css',`<br>`'text/xml',`<br>`'application/json',`<br>`'application/javascript'`<br>`]` |
 | `COMPRESS_LEVEL` | Specifies the gzip compression level. | `6` |
+| `COMPRESS_DEFLATE_LEVEL` | Specifies the deflate compression level. | `-1` |
 | `COMPRESS_MIN_SIZE` | Specifies the minimum file size threshold for compressing files. | `500` |
 | `COMPRESS_CACHE_KEY` | Specifies the cache key method for lookup/storage of response data. | `None` |
 | `COMPRESS_CACHE_BACKEND` | Specified the backend for storing the cached response data. | `None` |
 | `COMPRESS_REGISTER` | Specifies if compression should be automatically registered. | `True` |
-| `COMPRESS_ALGORITHM` | Supported compression algorithms. | `['br', 'gzip']` |
+| `COMPRESS_ALGORITHM` | Supported compression algorithms. | `['br', 'gzip', 'deflate']` |
 | `COMPRESS_BR_MODE` | For Brotli, the compression mode. The options are 0, 1, or 2. These correspond to "generic", "text" (for UTF-8 input), and "font" (for WOFF 2.0). | `0` |
 | `COMPRESS_BR_QUALITY` | For Brotli, the desired compression level. Proivdes control over the speed/compression density tradeoff. Higher values provide better compression at the cost of compression time. Ranges from 0 to 11. | `4` |
 | `COMPRESS_BR_WINDOW` | For Brotli, this specifies the base-2 logarithm of the sliding window size. Ranges from 10 to 24. | `22` |

flask_compress.py

@@ -5,6 +5,7 @@
 
 import sys
 from gzip import GzipFile
+import zlib
 from io import BytesIO
 
 from collections import defaultdict
@@ -70,11 +71,12 @@ def init_app(self, app):
             ('COMPRESS_BR_QUALITY', 4),
             ('COMPRESS_BR_WINDOW', 22),
             ('COMPRESS_BR_BLOCK', 0),
+            ('COMPRESS_DEFLATE_LEVEL', -1),
             ('COMPRESS_MIN_SIZE', 500),
             ('COMPRESS_CACHE_KEY', None),
             ('COMPRESS_CACHE_BACKEND', None),
             ('COMPRESS_REGISTER', True),
-            ('COMPRESS_ALGORITHM', ['br', 'gzip']),
+            ('COMPRESS_ALGORITHM', ['br', 'gzip', 'deflate']),
         ]
 
         for k, v in defaults:
@@ -102,7 +104,7 @@ def _choose_compress_algorithm(self, accept_encoding_header):
         means the client prefers that algorithm more).
 
         :param accept_encoding_header: Content of the `Accept-Encoding` header
-        :return: Name of a compression algorithm (e.g. `gzip` or `br`) or `None` if
+        :return: name of a compression algorithm (`gzip`, `deflate`, `br`) or `None` if
             the client and server don't agree on any.
         """
         # Map quality factors to requested algorithm names.
@@ -202,6 +204,9 @@ def compress(self, app, response, algorithm):
                           fileobj=gzip_buffer) as gzip_file:
                 gzip_file.write(response.get_data())
             return gzip_buffer.getvalue()
+        elif algorithm == 'deflate':
+            return zlib.compress(response.get_data(),
+                                 app.config['COMPRESS_DEFLATE_LEVEL'])
         elif algorithm == 'br':
             return brotli.compress(response.get_data(),
                                    mode=app.config['COMPRESS_BR_MODE'],

setup.py

@@ -10,7 +10,7 @@
     license='MIT',
     author='Thomas Mansencal',
     author_email='[email protected]',
-    description='Compress responses in your Flask app with gzip or brotli.',
+    description='Compress responses in your Flask app with gzip, deflate or brotli.',
     long_description=LONG_DESCRIPTION,
     long_description_content_type='text/markdown',
     py_modules=['flask_compress'],

tests/test_flask_compress.py

@@ -29,7 +29,11 @@ def test_min_size_default(self):
 
     def test_algorithm_default(self):
         """ Tests COMPRESS_ALGORITHM default value is correctly set. """
-        self.assertEqual(self.app.config['COMPRESS_ALGORITHM'], ['br', 'gzip'])
+        self.assertEqual(self.app.config['COMPRESS_ALGORITHM'], ['br', 'gzip', 'deflate'])
+
+    def test_default_deflate_settings(self):
+        """ Tests COMPRESS_DELATE_LEVEL default value is correctly set. """
+        self.assertEqual(self.app.config['COMPRESS_DEFLATE_LEVEL'], -1)
 
     def test_mode_default(self):
         """ Tests COMPRESS_BR_MODE default value is correctly set. """
@@ -145,6 +149,21 @@ def test_quality_level(self):
 
         self.assertNotEqual(response4_size, response11_size)
 
+    def test_deflate_compression_level(self):
+        """ Tests COMPRESS_DELATE_LEVEL correctly affects response data. """
+        self.app.config['COMPRESS_DEFLATE_LEVEL'] = -1
+        client = self.app.test_client()
+        response = client.get('/large/', headers=[('Accept-Encoding', 'deflate')])
+        response_size = len(response.data)
+
+        self.app.config['COMPRESS_DEFLATE_LEVEL'] = 1
+        client = self.app.test_client()
+        response = client.get('/large/', headers=[('Accept-Encoding', 'deflate')])
+        response1_size = len(response.data)
+
+        self.assertNotEqual(response_size, response1_size)
+
+
 class CompressionAlgoTests(unittest.TestCase):
     """
     Test different scenarios for compression algorithm negotiation between