Error handling

Every public method on the cache runs its underlying Redis call through RedisUtil::wrap(). That wrapper catches the extension's RedisException and rethrows it as a typed Raxos exception, so callers never have to deal with the raw extension errors.

The wrapper

RedisUtil::wrap() invokes a callable and converts any RedisException into a RedisErrorException.

<?php
declare(strict_types=1);

use Raxos\Cache\Redis\RedisUtil;

$value = RedisUtil::wrap($connection->get(...), 'user:42');

Exception types

All cache exceptions live in Raxos\Cache\Redis\Error, extend the base Exception from raxos/error and implement RedisCacheExceptionInterface from raxos/contract.

Exception	Thrown when
RedisErrorException	A RedisException from the extension is caught during any wrapped call.
RedisConnectionFailedException	The initial connect() call from the constructor fails.
RedisImplementationMissingException	The Redis class is not available on the system.
RedisCommandFailedException	A command level failure, such as an empty tag list or a database that cannot be selected.

Catching failures

Because every one of these exceptions implements RedisCacheExceptionInterface, you can catch a single interface to handle any cache failure.

<?php
declare(strict_types=1);

use Raxos\Cache\Redis\RedisCache;
use Raxos\Contract\Cache\RedisCacheExceptionInterface;

try {
    $cache = new RedisCache(prefix: 'app:');
    $cache->selectDatabase(1);
    $value = $cache->get('user:42');
} catch (RedisCacheExceptionInterface $err) {
    // Every cache failure ends up here.
}

When you extend RedisCache with additional raw Redis calls, route them through RedisUtil::wrap() too so they follow the same error convention.