Compress

The Compress filter's job is to provide a variety of compression implementations for compression and subsequent decompression of UDP data when sent between systems, such as a game client and game server.

Filter name

quilkin.filters.compress.v1alpha1.Compress

Configuration Examples

#![allow(unused)]
fn main() {
let yaml = "
version: v1alpha1
filters:
  - name: quilkin.filters.compress.v1alpha1.Compress
    config:
        on_read: COMPRESS
        on_write: DECOMPRESS
        mode: SNAPPY
clusters:
  - endpoints:
    - address: 127.0.0.1:7001
";
let config = quilkin::config::Config::from_reader(yaml.as_bytes()).unwrap();
assert_eq!(config.filters.load().len(), 1);
}

The above example shows a proxy that could be used with a typical game client, where the original client data is sent to the local listening port and then compressed when heading up to a dedicated game server, and then decompressed when traffic is returned from the dedicated game server before being handed back to game client.

It is worth noting that since the Compress filter modifies the entire packet, it is worth paying special attention to the order it is placed in your Filter configuration. Most of the time it will likely be the first or last Filter configured to ensure it is compressing the entire set of data being sent.

Configuration Options (Rust Doc)

$schema: http://json-schema.org/draft-07/schema#
title: Config
type: object
required:
- on_read
- on_write
properties:
  mode:
    default: SNAPPY
    allOf:
    - $ref: '#/definitions/Mode'
  on_read:
    $ref: '#/definitions/Action'
  on_write:
    $ref: '#/definitions/Action'
definitions:
  Action:
    description: Whether to do nothing, compress or decompress the packet.
    type: string
    enum:
    - DO_NOTHING
    - COMPRESS
    - DECOMPRESS
  Mode:
    description: The library to use when compressing.
    type: string
    enum:
    - SNAPPY
    - LZ4

Compression Modes

Snappy

Snappy is a compression/decompression library. It does not aim for maximum compression, or compatibility with any other compression library; instead, it aims for very high speeds and reasonable compression.

This compression method is provided by rust-snappy.

Due to the small size of packets, this only encodes and decodes the non-streaming version of the format described here.

- name: quilkin.filters.compress.v1alpha1.Compress
    config:
        on_read: COMPRESS
        on_write: DECOMPRESS
        mode: SNAPPY

LZ4

LZ4 is lossless compression algorithm, providing compression speed > 500 MB/s per core, scalable with multi-cores CPU. It features an extremely fast decoder, with speed in multiple GB/s per core, typically reaching RAM speed limits on multi-core systems.

This compression method is provided by lz4_flex.

Due to the small size of packets, this only encodes and decodes the block version of the format described. If your game client/server itself is performing LZ4 de/compression it needs to encode or decode a varint of the uncompressed packet size (maximum 2^16) since that is not part of the LZ4 block format. The varint is of the same exact form as that used by snappy.

- name: quilkin.filters.compress.v1alpha1.Compress
    config:
        on_read: COMPRESS
        on_write: DECOMPRESS
        mode: LZ4

Metrics

quilkin_filter_int_counter{label="compressed_bytes_total"} Total number of compressed bytes either received or sent.
quilkin_filter_int_counter{label="decompressed_bytes_total"} Total number of decompressed bytes either received or sent.

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