BC
Flexihash
Flexihash is a small PHP library which implements consistent hashing, which is most useful in distributed caching.
Note
This repo is a fork of https://github.com/pda/flexihash which had no release since 2020.
Originally authored by @pda, @dmnc and @serima
Installation
Composer is the recommended installation technique. You can find flexihash on Packagist so installation is as easy as
composer require bcremer/flexihash
or in your composer.json
{
"require": {
"bcremer/flexihash": "^5.0.0"
}
}Usage
$hash = new Flexihash();
// bulk add
$hash->addTargets(['cache-1', 'cache-2', 'cache-3']);
// simple lookup
$hash->lookup('object-a'); // "cache-1"
$hash->lookup('object-b'); // "cache-2"
// add and remove
$hash->addTarget('cache-4');
$hash->removeTarget('cache-1');
// lookup with next-best fallback (for redundant writes)
$hash->lookupList('object', 2); // ["cache-2", "cache-4"]
// remove cache-2, expect object to hash to cache-4
$hash->removeTarget('cache-2');
$hash->lookup('object'); // "cache-4"Benchmarks
Performance can be tested with PHPBench.
git checkout main
./vendor/bin/phpbench run --report=aggregate --iterations=4 --tag=branch_main
git checkout some-branch
./vendor/bin/phpbench run --report=aggregate --iterations=4 --ref=branch_mainTests
Unit Test
composer testBenchmark Test
vendor/bin/phpunit tests/BenchmarkTest.phpFurther Reading
On this page
MIT License
Created November 20, 2024
Updated May 26, 2025