predis-commands

Adds some Lua-based atomic commands to Predis.

Motivation

Any individual Redis command is always atomic because Redis is single threaded. In some cases you may want to run several Redis commands atomically.

There are two common ways to achieve this:

• Redis transactions. It utilizes MULTI/EXEC Redis commands to run some commands in sequence It also uses WATCH/DISCARD Redis commands for CAS optimistic concurrency.
• Redis scripts. This one is transactional by definition: Redis uses the same Lua interpreter to run all the commands and guarantees that no other script or Redis command will be executed while a script is being executed.

This project uses Lua Scripting approach as it's usually both simpler and faster.

Installation

composer require angyvolin/predis-commands

What's included?

As of now, the predis-commands project extends Predis with following commands:

ZPOP - Removes and returns the top value in a zset, with its score.
ZRPOP - Removes and returns the bottom value in a zset, with its score.

How to use predis-commands ...

... in plain PHP

Code snippet below demonstrates how to use predis-commands regardless of any framework

<?php

require __DIR__.'/../vendor/autoload.php';

use Angyvolin\Predis\Command;

$client = new Predis\Client();
$client->getProfile()->defineCommand('zpop', Command\ZSetPop::class);
$client->getProfile()->defineCommand('zrpop', Command\ZSetReversePop::class);

... in Silex application

Code snippet below demonstrates integration with Silex application

<?php

use Pimple\Container;
use Pimple\ServiceProviderInterface;
use Angyvolin\Predis\Command;

class PredisCommandsServiceProvider implements ServiceProviderInterface
{
    public function register(Container $app)
    {
        $app->extend('redis', function ($redis) {
            /* @var \Predis\Client $redis */
            $redis->getProfile()->defineCommand('zpop', Command\ZSetPop::class);
            $redis->getProfile()->defineCommand('zrpop', Command\ZSetReversePop::class);
        
            return $redis;
        });
    }
}

Tests:

Tu run tests execute following command in a root directory of the predis-commands project:

phpunit

License

MIT License