eZ\Publish\Core\Persistence\Cache\InMemory\MetadataCachePool

Complexity

Total Complexity

10

Size/Duplication

Total Lines	109
Duplicated Lines	0 %

Coupling/Cohesion

Components	1
Dependencies	0

Importance

Changes

0

5 Methods

Rating	Name	Duplication	Size	Complexity
A	__construct()	0	4	1
A	get()	0	18	4
A	set()	0	9	2
A	delete()	0	8	2
A	clear()	0	4	1

<?php

/**
 * File containing MetadataCachePool class.
 *
 * @copyright Copyright (C) eZ Systems AS. All rights reserved.
 * @license For full copyright and license information view LICENSE file distributed with this source code.
 */
declare(strict_types=1);

namespace eZ\Publish\Core\Persistence\Cache\InMemory;

/**
 * InMemory Metadata Cache Pool.
 *
 * Burst cache for use on meta data only, meaning:
 * - data with in-frequently changes done on other threads/processes/requests
 * - when they do the system unlikely to crash from it
 *
 * Assuming cache is kept with low TTL (for up to slow request lengths like )
 *
 * E.g can be used for SPI data for Sections, ContentTypes, ObjectStates, ..
 * But not Content, Locations, (...).
 *
 * Design here is aligned with PSR-16 (but further simplified).
 *
 * @internal Only for use in eZ\Publish\Core\Persistence\Cache.
 */
class MetadataCachePool
{
    private const DEFAULT_CACHE_TTL = 4;

    /**
     * @var int Cache Time to Live, in seconds. This is only for how long we keep cache object around in-memory.
     */
    private $cacheTTL;

    /**
     * Cache objects by primary key.
     *
     * @TODO set to use WeakMap if present in __construct() ??
     *       https://secure.php.net/manual/en/class.weakmap.php
     *       At least very relevant for possible burst cache impl for Content.
     *
     * @var object[]
     */
    private $cache = [];

    /**
     * Secondary keys to primary key map.
     *
     * @var string[]
     */
    private $cacheSecondaryIndex = [];

    /**
     * @var int[] Timestamp for individual cache by primary key.
     */
    private $cacheTime = [];

    /**
     * Language Cache constructor.
     *
     * @param int $cacheTTL Seconds for the cache to live.
     */
    public function __construct(int $cacheTTL = self::DEFAULT_CACHE_TTL)
    {
        $this->cacheTTL = $cacheTTL;
    }

    /**
     * Returns a cache value.
     *
     * @param string $key Primary or secondary key to look for cache on.
     *
     * @return object|null Cache object if there is one and if not expired.
     */
    public function get($key): ?object
    {
        if (isset($this->cacheSecondaryIndex[$key])) {
            $key = $this->cacheSecondaryIndex[$key];
        }

        if (!isset($this->cache[$key])) {
            return null;
        }

        if ($this->cacheTime[$key] + $this->cacheTTL > time()) {
            $this->delete($key);

            return null;
        }

        return $this->cache[$key];
    }

    /**
     * Set object in in-memory cache.
     *
     * Should only set Cache hits here!
     *
     * @param string $key
     * @param object $object
     * @param array $secondaryIndexes
     */
    public function set(string $key, object $object, array $secondaryIndexes = []): void
    {
        $this->cache[$key] = $object;
        $this->cacheTime[$key] = time();

        foreach ($secondaryIndexes as $index) {
            $this->cacheSecondaryIndex[$index] = $key;
        }
    }

    /**
     * Removes multiple in-memory cache from the pool.
     *
     * @param string[] $keys An array of keys that should be removed from the pool.

There is no parameter named $keys. Was it maybe removed?

     */
    public function delete(string $key): void
    {
        unset($this->cache[$key], $this->cacheTime[$key]);

        if ($index = $this->cacheSecondaryIndex[$key] ?? null) {
            unset($this->cacheSecondaryIndex[$key], $this->cache[$index], $this->cacheTime[$index]);
        }
    }

    /**
     * Deletes all cache in the in-memory pool.
     */
    public function clear(): void
    {
        $this->cache = $this->cacheSecondaryIndex = $this->cacheTime = [];
    }
}