predis-commands

Adds some [Lua][4]-based atomic commands to Predis., _(*1)

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., _(*2)

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., _(*3)

This project uses Lua Scripting approach as it's usually both simpler and faster., _(*4)

Installation

composer require angyvolin/predis-commands

What's included?

As of now, the predis-commands project extends Predis with following commands:, _(*5)

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, _(*6)

<?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, _(*7)

<?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;
        });
    }
}