ngx_brotli

Brotli is a generic-purpose lossless compression algorithm that compresses data using a combination of a modern variant of the LZ77 algorithm, Huffman coding and 2nd order context modeling, with a compression ratio comparable to the best currently available general-purpose compression methods. It is similar in speed with deflate but offers more dense compression.

ngx_brotli is a set of two nginx modules:

• ngx_brotli filter module - used to compress responses on-the-fly,
• ngx_brotli static module - used to serve pre-compressed files.

Status

Both Brotli library and nginx module are under active development.

Installation

$ cd nginx-1.x.x
$ ./configure --add-module=/path/to/ngx_brotli
$ make && make install

Configuration directives

brotli_static

• syntax: brotli_static on|off|always
• default: off
• context: http, server, location

Enables or disables checking of the existence of pre-compressed files with.br extension. With the always value, pre-compressed file is used in all cases, without checking if the client supports it.

brotli

• syntax: brotli on|off
• default: off
• context: http, server, location, if

Enables or disables on-the-fly compression of responses.

brotli_types

• syntax: brotli_types <mime_type> [..]
• default: text/html
• context: http, server, location

Enables on-the-fly compression of responses for the specified MIME types in addition to text/html. The special value * matches any MIME type. Responses with the text/html MIME type are always compressed.

brotli_buffers

• syntax: brotli_buffers <number> <size>
• default: 32 4k|16 8k
• context: http, server, location

Sets the number and size of buffers used to compress a response. By default, the buffer size is equal to one memory page. This is either 4k or 8k, depending on a platform.

brotli_comp_level

• syntax: brotli_comp_level <level>
• default: 6
• context: http, server, location

Sets Brotli quality (compression) level. Acceptable values are in the range from 0 to 11.

brotli_window

• syntax: brotli_window <size>
• default: 512k
• context: http, server, location

Sets Brotli window size. Acceptable values are 1k, 2k, 4k, 8k, 16k, 32k, 64k, 128k, 256k, 512k, 1m, 2m, 4m, 8m and 16m.

brotli_min_length

• syntax: brotli_min_length <length>
• default: 20
• context: http, server, location

Sets the minimum length of a response that will be compressed. The length is determined only from the Content-Length response header field.

Variables

$brotli_ratio

Achieved compression ratio, computed as the ratio between the original and compressed response sizes.

Contributing

See Contributing.

License

Copyright (C) 2002-2015 Igor Sysoev
Copyright (C) 2011-2015 Nginx, Inc.
Copyright (C) 2015 Google Inc.
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
   notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
   notice, this list of conditions and the following disclaimer in the
   documentation and/or other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.