NullRedis (file-backed Redis-like shim)

NullRedis is a tiny, dependency-free, file-backed shim that mimics a small subset of Redis commands:

• KV: get, set, setex, exists, expire
• Sets: sAdd, sMembers
• Sorted sets: zadd, zcard, zremrangebyscore
• Admin: flushAll

It’s useful as a drop-in fallback when Redis is unavailable, or as a lightweight cache/rate-limiter without running a server.

Install

Via Composer (recommended)

composer require officialaudite/nullredis

require __DIR__ . '/vendor/autoload.php';
use NullRedis\NullRedis;
$cache = new NullRedis(__DIR__.'/cache'); // optional custom cache dir

Manual (copy file)

Copy src/NullRedis.php into your project and include it.

require_once __DIR__.'/src/NullRedis.php';
$cache = new \NullRedis\NullRedis(__DIR__.'/cache');

Usage

Basic KV

use NullRedis\NullRedis;
$cache = new NullRedis(__DIR__.'/cache');
$cache->set('greeting', 'hello');
echo $cache->get('greeting'); // hello
$cache->setex('temp', 2, 'short');
sleep(3);
var_dump($cache->get('temp')); // NULL after expiry

Sets

$cache->sAdd('bad_agents', 'curl/7.88');
$cache->sAdd('bad_agents', 'bot');
print_r($cache->sMembers('bad_agents'));

Sorted sets (rate limiting)

$user = '127.0.0.1';
$key = 'rate:'.$user;
$now = time(); $window = 2; $max = 5;
$cache->zremrangebyscore($key, 0, $now - $window);
$cache->zadd($key, $now, (string)$now);
if ($cache->zcard($key) > $max) { http_response_code(429); exit('Too Many Requests'); }
$cache->expire($key, $window+1);

Development

Run tests

composer install
composer test

Roadmap

• KV basics: get, set, setex, exists, expire
• Admin: flushAll
• Sorted sets (MVP): zadd, zcard, zremrangebyscore
• Sets (MVP): sAdd/sMembers
• KV more: del, mset, mget, incr, decr, incrBy, decrBy, pexpire, ttl, pttl, persist, type, keys
• Sets more: sismember, srem, scard
• Sorted sets more: zrange, zrevrange, zrangebyscore, zrem, zscore, zcount
• Lists: lpush, rpush, lpop, rpop, llen, lrange
• Hashes: hset, hget, hmset, hmget, hgetall, hdel, hexists, hincrby
• DB/admin: select (db directories), dbsize, flushdb
• Docs: compatibility matrix vs phpredis
• Optional: PHPCS and coding-style CI

Non-goals (for now): Pub/Sub, Streams, Lua (eval), blocking ops (blpop, brpop), Cluster.

Notes

• Per-key JSON files under cache/, sharded by the first 2 chars of SHA1(key)
• Lazy TTL expiration on read
• Single-host, low-contention environments recommended

License

MIT — see LICENSE