README

CompressionBuffer

CompressionBuffer provides easy access to zstd, brotli, and gzip output buffering with PHP on any web server. You can even get zstd output compression with the PHP development server.

Features

• Respects the Accept-Encoding header sent by the client, including the specified priority for each compression method.
• Allows zstd, brotli, gzip and deflate compression methods to be used on any web server.
• All included compression methods have been benchmarked with compression levels carefully selected for the ideal balance between speed and size reduction.
• Auto-selects the compression method based on client headers and available PHP extensions.
• Automatically sends the appropriate headers.

Requirements

• A PHP application using output buffering.
• PHP 8.0 or greater.
• ext-brotli if you want brotli compression.
• ext-zstdif you want zstd compression.
• ext-zlib if you want gzip / deflate compression.

Installation & Usage

Install via composer:

composer require hostbybelle/compressionbuffer

Enabling in your application:

<?php
use HostByBelle\CompressionBuffer;

require 'vendor/autoload.php';

CompressionBuffer::setUp(); // Have compressionBuffer detect & sort the compression methods
ob_start([CompressionBuffer::class, 'handler']); // Register it

// Send some content to the output buffer
echo "Lorem ipsum dolor sit amet, consectetur adipiscing elit,";

// Finally send it to the browser & let CompressionBuffer do it's magic.
ob_end_flush();

Toggling CompressionBuffer's status:

CompressionBuffer::enable(); // Enable output compression (enabled by default)
CompressionBuffer::disable(); // Disable output compression
CompressionBuffer::isEnabled(); // Check if it's currently enabled or not

Compression Method Tests & Results

Compression Methods, Ranked

1. zstd is the fastest, most efficient compression method. On it's lowest level it will be 4.5x faster than gzip while producing a 5% smaller output. When matching gzip on it's fastest setting, zstd will produce a 10% smaller output.
2. brotli is a good middle-ground between the two alternatives. It's lowest setting is still about 3x faster than gzip while producing a 5% smaller output. It will produce a similar overall compression level to zstd, but will do so at a slower pace. Still an overall great choice.
3. gzip is the longstanding, tried & true compression method, but is quite slow compared to the new alternatives and will produce larger outputs while doing so.

These stats are based off some simple testing we've performed on a 4mb HTML document containing the book war and peace. This choice was inspired by jab4/zstdtest & represents a large document a server might serve. Our testing with small documents shows all 3 compression methods have very similar compression levels and overall processing time.

The results of our testing can be found here on Google Sheets.

Compression Levels Used

• zstd: Level 3. Level 4 would also be a good option as it will still be faster than the rest, however at level 3 zstd far exceeds the other options for speed while matching them in overall compression level and level 4 is only 38% the speed of level 3 for for only .4% more compression.
• brotli: Level 3. Level 4 does come with a noticeable increase to compression level, but does so in 3x the time. At level 3 brotli provides a similar compression level to gzip, but at around 4.5x the speed.
• gzip: Level 4 was chosen as it's the highest level before gzip's speed quickly drops off to nearly unusable levels. This does come at a slight cost to overall compression level, but helps keep application response times quick.