src/Bridge.php
<?php
namespace Axm\CakePHPSimpleCacheBridge;
use Cake\Cache\Cache;
use Cake\Cache\CacheEngine;
use Psr\SimpleCache\CacheInterface;
/**
* Class Bridge
* Adds a SimpleCache interface on a Cake\Cache\CacheEngine
*/
class Bridge implements CacheInterface
{
const INVALID_KEY = 'Key provided must be a string';
const INVALID_KEYS = 'Keys provided must an array or Traversable with string keys';
const DURATION = 'duration';
/**
* @var string
*/
protected $cache_config;
/**
* @var CacheEngine
*/
protected $cache_engine;
/**
* @var int
*/
protected $original_duration;
/**
* Bridge constructor.
* @param string $cache_config
*/
public function __construct($cache_config)
{
$this->cache_config = $cache_config;
$this->cache_engine = Cache::engine($cache_config);
$this->original_duration = $this->cache_engine->getConfig(self::DURATION);
}
/**
* Fetches a value from the cache.
*
* @param string $key The unique key of this item in the cache.
* @param mixed $default Default value to return if the key does not exist.
*
* @return mixed The value of the item from the cache, or $default in case of cache miss.
*
* @throws InvalidArgumentException thrown if the $key is not a string
*/
public function get($key, $default = null)
{
if ($this->keyIsInvalid($key)) {
throw new InvalidArgumentException(self::INVALID_KEY);
}
$value = $this->getCacheEngineWithTTL()->read($key);
return $value === false
? $default
: $value;
}
/**
* Persists data in the cache, uniquely referenced by a key with an optional expiration TTL time.
*
* @param string $key The key of the item to store.
* @param mixed $value The value of the item to store, must be serializable.
* @param null|int|\DateInterval $ttl Optional. The TTL value of this item. If no value is sent then uses the Cake\Cache\Engine's duration
*
* @return bool True on success and false on failure.
*
* @throws InvalidArgumentException thrown if the $key is not a string
*/
public function set($key, $value, $ttl = null)
{
if ($this->keyIsInvalid($key)) {
throw new InvalidArgumentException(self::INVALID_KEY);
}
$engine = $this->getCacheEngineWithTTL($ttl);
$success = $engine->write($key, $value);
$this->restoreCacheEngineDuration($ttl);
return $success;
}
/**
* Delete an item from the cache by its unique key.
*
* @param string $key The unique cache key of the item to delete.
*
* @return bool True if the item was successfully removed. False if there was an error.
*
* @throws InvalidArgumentException thrown if the $key is not a string
*/
public function delete($key)
{
if ($this->keyIsInvalid($key)) {
throw new InvalidArgumentException(self::INVALID_KEY);
}
return $this->getCacheEngineWithTTL()->delete($key);
}
/**
* Wipes clean the entire cache's keys.
*
* @return bool True on success and false on failure.
*/
public function clear()
{
return $this->getCacheEngineWithTTL()->clear(false);
}
/**
* Obtains multiple cache items by their unique keys.
*
* NOTE: Cake\Cache\CacheEngine returns FALSE on cache misses making the use of $default unreliable
*
* @param iterable $keys A list of keys that can obtained in a single operation.
* @param mixed $default Default value to return for keys that do not exist.
*
* @return iterable A list of key => value pairs. Cache keys that do not exist or are stale will have $default as value.
*
* @throws InvalidArgumentException thrown if $keys is neither an array nor a Traversable,or if any of the $keys are not a legal value.
*/
public function getMultiple($keys, $default = null)
{
if ($this->keysAreInvalid($keys)) {
throw new InvalidArgumentException(self::INVALID_KEYS);
}
$values = $this->getCacheEngineWithTTL()->readMany($this->keysAsArray($keys));
foreach ($values as $key => $value) {
$values[$key] = ($value === false)
? $default
: $value;
}
return $values;
}
/**
* Persists a set of key => value pairs in the cache, with an optional TTL.
*
* @param iterable $values A list of key => value pairs for a multiple-set operation.
* @param null|int|\DateInterval $ttl Optional. The TTL value of this item. If no value is sent and
* the driver supports TTL then the library may set a default value
* for it or let the driver take care of that.
*
* @return bool True on success and false on failure.
*
* @throws InvalidArgumentException thrown if $values is neither an array nor a Traversable, or if any of the keys are not a legal value.
*/
public function setMultiple($values, $ttl = null)
{
if ($this->keysAreInvalid($values)) {
throw new InvalidArgumentException('Values provided must an array or Traversable with string keys');
}
return $this->getCacheEngineWithTTL($ttl)->writeMany($this->keysAsArray($values));
}
/**
* Deletes multiple cache items in a single operation.
*
* @param iterable $keys A list of string-based keys to be deleted.
*
* @return bool True if the items were successfully removed. False if there was an error.
*
* @throws InvalidArgumentException thrown if $keys is neither an array nor a Traversable, or if any of the $keys are not a legal value.
*/
public function deleteMultiple($keys)
{
if ($this->keysAreInvalid($keys)) {
throw new InvalidArgumentException(self::INVALID_KEYS);
}
return $this->getCacheEngineWithTTL()->deleteMany($this->keysAsArray($keys));
}
/**
* Determines whether an item is present in the cache.
*
* NOTE: It is recommended that has() is only to be used for cache warming type purposes
* and not to be used within your live applications operations for get/set, as this method
* is subject to a race condition where your has() will return true and immediately after,
* another script can remove it making the state of your app out of date.
*
* ALSO NOTE: Cake\Cache\CacheEngine returns FALSE on cache misses making this method unreliable
*
* @param string $key The cache item key.
*
* @return bool
*
* @throws InvalidArgumentException thrown if the $key is not a string
*/
public function has($key)
{
return (bool)$this->get($key, false);
}
protected function getCacheEngineWithTTL($ttl = null)
{
if (!is_null($ttl)) {
$duration = $this->ttlToDuration($ttl);
$this->cache_engine->setConfig(self::DURATION, $duration);
}
return $this->cache_engine;
}
protected function restoreCacheEngineDuration($ttl = null)
{
if (!is_null($ttl)) {
$this->cache_engine->setConfig(self::DURATION, $this->original_duration);
}
}
protected function ttlToDuration($ttl)
{
return ($ttl instanceof \DateInterval)
? $ttl->format('%s')
: (int)$ttl;
}
protected function keyIsInvalid($key)
{
return !is_string($key);
}
protected function keysAreInvalid($keys)
{
if (!is_array($keys) && !is_object($keys) && !($keys instanceof \Traversable)) {
return true;
}
foreach ($keys as $key) {
if ($this->keyIsInvalid($key)) {
return true;
}
}
return false;
}
protected function keysAsArray($keys)
{
if (is_array($keys)) {
return $keys;
}
return iterator_to_array($keys);
}
}