README

This is a trivial implementation of PSR CacheInterface using an in-memory array.

PSR Cache implementations are frequently heavyweight. They can provide a ton of backend options that the user may not need or they might be closely tied to a specific framework that the user doesn't use.

This library is designed to provide a simple, lightweight, and (nearly) dependency-free PSR cache implementation that can be used as a default or placeholder.

For example, this is useful in libraries where a cache is necessary but the implementation will be chosen by the library's users. It can also be used as a development dependency to provide a cache implementation for testing.

The cache has a fully-tested implementation of TTLs with microsecond precision, so if you set something to expire in one second, it will expire in one second, not 0-2 seconds.

The cache can be prepopulated with a JSON string or an array of data. It also supports JSON serialization so you can persist the cache or inspect its contents if necessary. (Also useful for testing.)

Requirements

This library requires PHP 8.0 or later. psr/simple-cache is the only runtime dependency.

Installation

composer require jdwx/array-cache

Usage

The ArrayCache class implements the PSR-16 CacheInterface.

In addition, it can be preloaded with data:

use JDWX\ArrayCache\ArrayCache;


$cache = new ArrayCache([ 'foo' => 'bar', 'baz' => 'qux' ]);

It can be serialized to JSON, which will preserve the TTLs:

$cache = new ArrayCache();
$cache->set( 'foo', 'bar' );
$cache->set( 'baz', 'qux', 5 );
$json = json_encode($cache);

It can also be preloaded with JSON:

$st = '{"foo":"bar","baz":"qux"}';
$cache = new ArrayCache($st);
assert( $cache->get('foo') === 'bar' );
assert( $cache->get('baz') === 'qux' );

// or

$cache = new ArrayCache();
$cache->set( 'foo', 'bar' );
$cache->set( 'baz', 'qux', 5 );
$cache->set( 'quux', 'corge' );

$st = json_encode($cache);

$cache = new ArrayCache($st);
assert( $cache->get('foo') === 'bar' );

Both importing and exporting JSON will drop expired items.

Stability

This library is stable and has a full suite of unit tests. It is considered suitable for production use within its problem domain. I.e., don't use this where you should be using something like Redis or symfony/cache.

History

This library was created in 2024 because (the otherwise excellent) cache/array-adapter is no longer maintained.

jdwx / array-cache

Maintainers

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