Prefixed cache decorators

This package adds a fixed prefix to keys sent to an existing PSR-6 or PSR-16 cache.

Unlike NamespacedCachePool, clearing a prefixed cache clears the entire underlying pool. Use the namespaced package when you need isolated clearing.

Installation

composer require cache/prefixed-cache:^2.0

Usage

use Cache\Adapter\PHPArray\ArrayCachePool;
use Cache\Prefixed\PrefixedCachePool;

$sharedPool = new ArrayCachePool();
$pool = PrefixedCachePool::create($sharedPool, 'billing.');

create() returns a taggable decorator when the wrapped PSR-6 pool supports native tags. Its cache items keep setTags(), and tag invalidation uses the wrapped pool.

The public constructor remains available. It always returns the basic PrefixedCachePool type, so use create() when you need tag support.

Use PrefixedSimpleCache to decorate a PSR-16 cache.

Prefixes are encoded before they are joined to public keys. The reversible _xHH_ format leaves ASCII letters, digits, _, and . unchanged. Every other byte is encoded, including each byte in non-ASCII text. A literal lowercase _x sequence is also encoded so it cannot look like an encoded byte.

Before upgrading to version 2 or rolling back from it, clear affected caches when a prefix contains bytes outside [A-Za-z0-9_.] or a lowercase _x sequence. Those prefixes use different storage keys in version 2.

Contributing

Send pull requests to the main repository. Report issues on the GitHub issue tracker.