Cache and Locks

Cache

use plato\cache\cache;

cache::set('user:7', $user, 300);
$user = cache::get('user:7');
$exists = cache::has('user:7');

$user = cache::remember('user:7', 300, fn () => load_user(7));
cache::tags(['user', 'tenant:3'])->set('user:7', $user, 300);
cache::tags(['user'])->flush();

Stores are redis, file, memcached, and memory. Memory is local to the current process; file is suitable for ordinary single-host caching; atomic counters across workers require Redis.

A get() result alone cannot prove a key exists because false, 0, empty strings, and empty arrays are valid values. Use has() when the distinction matters.

PSR-16

With psr/simple-cache installed, pass plato\psr\cache to libraries requiring Psr\SimpleCache\CacheInterface.

Distributed locks

use plato\lock;

$result = lock::guard('invoice:42', function () {
    return issue_invoice(42);
}, timeout: 3, expire: 15);

plato\lock uses Redis only. Values include holder tokens, and unlock or renewal operations use atomic scripts. The lock server must not use a maxmemory policy that can arbitrarily evict lock keys.