README

Yii Cache Library - APCu Handler

This package uses the PHP APCu extension and implements PSR-16 cache.

This option can be considered as the fastest one when dealing with a cache for a centralized thick application (e.g. one server, no dedicated load balancers, etc.).

Requirements

PHP 8.0 or higher.
APCu PHP extension.

Installation

The package could be installed with Composer:

composer require yiisoft/cache-apcu

General usage

The package does not contain any additional functionality for interacting with the cache, except those defined in the PSR-16 interface.

$cache = new \Yiisoft\Cache\Apcu\ApcuCache();
$parameters = ['user_id' => 42];
$key = 'demo';

// try retrieving $data from cache
$data = $cache->get($key);

if ($data === null) {
    // $data is not found in cache, calculate it from scratch
    $data = calculateData($parameters);
    
    // store $data in cache for an hour so that it can be retrieved next time
    $cache->set($key, $data, 3600);
}

// $data is available here

In order to delete value you can use:

$cache->delete($key);
// Or all cache
$cache->clear();

To work with values in a more efficient manner, batch operations should be used:

getMultiple()
setMultiple()
deleteMultiple()

This package can be used as a cache handler for the Yii Caching Library.

Cleaning up APCu cache

Typically the web processes are separate from CLI so these do not share the same cache instance. Thus, special handling in the web is needed for the case. First, a web-acessible script apc_clear.php like the following:

<?php
if (in_array(@$_SERVER['REMOTE_ADDR'], ['127.0.0.1', '::1'])) {
  apc_clear_cache();
  apc_clear_cache('user');
  apc_clear_cache('opcode');
  echo json_encode(['success' => true]);
}

And finally, you need some code that calls it:

$url = 'http://localhost/apc_clear.php';
$result = json_decode(file_get_contents($url));

if (empty($result['success'])) {
  echo "There was an error cleaning up APCu cache.\n".
}