framework/caching/Cache.php
<?php
/**
* @link https://www.yiiframework.com/
* @copyright Copyright (c) 2008 Yii Software LLC
* @license https://www.yiiframework.com/license/
*/
namespace yii\caching;
use Yii;
use yii\base\Component;
use yii\helpers\StringHelper;
/**
* Cache is the base class for cache classes supporting different cache storage implementations.
*
* A data item can be stored in the cache by calling [[set()]] and be retrieved back
* later (in the same or different request) by [[get()]]. In both operations,
* a key identifying the data item is required. An expiration time and/or a [[Dependency|dependency]]
* can also be specified when calling [[set()]]. If the data item expires or the dependency
* changes at the time of calling [[get()]], the cache will return no data.
*
* A typical usage pattern of cache is like the following:
*
* ```php
* $key = 'demo';
* $data = $cache->get($key);
* if ($data === false) {
* // ...generate $data here...
* $cache->set($key, $data, $duration, $dependency);
* }
* ```
*
* Because Cache implements the [[\ArrayAccess]] interface, it can be used like an array. For example,
*
* ```php
* $cache['foo'] = 'some data';
* echo $cache['foo'];
* ```
*
* Derived classes should implement the following methods which do the actual cache storage operations:
*
* - [[getValue()]]: retrieve the value with a key (if any) from cache
* - [[setValue()]]: store the value with a key into cache
* - [[addValue()]]: store the value only if the cache does not have this key before
* - [[deleteValue()]]: delete the value with the specified key from cache
* - [[flushValues()]]: delete all values from cache
*
* For more details and usage information on Cache, see the [guide article on caching](guide:caching-overview).
*
* @author Qiang Xue <qiang.xue@gmail.com>
* @since 2.0
*/
abstract class Cache extends Component implements CacheInterface
{
/**
* @var string a string prefixed to every cache key so that it is unique globally in the whole cache storage.
* It is recommended that you set a unique cache key prefix for each application if the same cache
* storage is being used by different applications.
*
* To ensure interoperability, only alphanumeric characters should be used.
*/
public $keyPrefix;
/**
* @var array|null|false the functions used to serialize and unserialize cached data. Defaults to null, meaning
* using the default PHP `serialize()` and `unserialize()` functions. If you want to use some more efficient
* serializer (e.g. [igbinary](https://pecl.php.net/package/igbinary)), you may configure this property with
* a two-element array. The first element specifies the serialization function, and the second the deserialization
* function. If this property is set false, data will be directly sent to and retrieved from the underlying
* cache component without any serialization or deserialization. You should not turn off serialization if
* you are using [[Dependency|cache dependency]], because it relies on data serialization. Also, some
* implementations of the cache can not correctly save and retrieve data different from a string type.
*/
public $serializer;
/**
* @var int default duration in seconds before a cache entry will expire. Default value is 0, meaning infinity.
* This value is used by [[set()]] if the duration is not explicitly given.
* @since 2.0.11
*/
public $defaultDuration = 0;
/**
* @var bool whether [igbinary serialization](https://pecl.php.net/package/igbinary) is available or not.
*/
private $_igbinaryAvailable = false;
/**
* {@inheritdoc}
*/
public function init()
{
parent::init();
$this->_igbinaryAvailable = \extension_loaded('igbinary');
}
/**
* Builds a normalized cache key from a given key.
*
* If the given key is a string containing alphanumeric characters only and no more than 32 characters,
* then the key will be returned back prefixed with [[keyPrefix]]. Otherwise, a normalized key
* is generated by serializing the given key, applying MD5 hashing, and prefixing with [[keyPrefix]].
*
* @param mixed $key the key to be normalized
* @return string the generated cache key
*/
public function buildKey($key)
{
if (is_string($key)) {
$key = ctype_alnum($key) && StringHelper::byteLength($key) <= 32 ? $key : md5($key);
} else {
if ($this->_igbinaryAvailable) {
$serializedKey = igbinary_serialize($key);
} else {
$serializedKey = serialize($key);
}
$key = md5($serializedKey);
}
return $this->keyPrefix . $key;
}
/**
* Retrieves a value from cache with a specified key.
* @param mixed $key a key identifying the cached value. This can be a simple string or
* a complex data structure consisting of factors representing the key.
* @return mixed the value stored in cache, false if the value is not in the cache, expired,
* or the dependency associated with the cached data has changed.
*/
public function get($key)
{
$key = $this->buildKey($key);
$value = $this->getValue($key);
if ($value === false || $this->serializer === false) {
return $value;
} elseif ($this->serializer === null) {
$value = unserialize((string)$value);
} else {
$value = call_user_func($this->serializer[1], $value);
}
if (is_array($value) && !($value[1] instanceof Dependency && $value[1]->isChanged($this))) {
return $value[0];
}
return false;
}
/**
* Checks whether a specified key exists in the cache.
* This can be faster than getting the value from the cache if the data is big.
* In case a cache does not support this feature natively, this method will try to simulate it
* but has no performance improvement over getting it.
* Note that this method does not check whether the dependency associated
* with the cached data, if there is any, has changed. So a call to [[get]]
* may return false while exists returns true.
* @param mixed $key a key identifying the cached value. This can be a simple string or
* a complex data structure consisting of factors representing the key.
* @return bool true if a value exists in cache, false if the value is not in the cache or expired.
*/
public function exists($key)
{
$key = $this->buildKey($key);
$value = $this->getValue($key);
return $value !== false;
}
/**
* Retrieves multiple values from cache with the specified keys.
* Some caches (such as memcache, apc) allow retrieving multiple cached values at the same time,
* which may improve the performance. In case a cache does not support this feature natively,
* this method will try to simulate it.
*
* @param string[] $keys list of string keys identifying the cached values
* @return array list of cached values corresponding to the specified keys. The array
* is returned in terms of (key, value) pairs.
* If a value is not cached or expired, the corresponding array value will be false.
* @deprecated This method is an alias for [[multiGet()]] and will be removed in 2.1.0.
*/
public function mget($keys)
{
return $this->multiGet($keys);
}
/**
* Retrieves multiple values from cache with the specified keys.
* Some caches (such as memcache, apc) allow retrieving multiple cached values at the same time,
* which may improve the performance. In case a cache does not support this feature natively,
* this method will try to simulate it.
* @param string[] $keys list of string keys identifying the cached values
* @return array list of cached values corresponding to the specified keys. The array
* is returned in terms of (key, value) pairs.
* If a value is not cached or expired, the corresponding array value will be false.
* @since 2.0.7
*/
public function multiGet($keys)
{
$keyMap = [];
foreach ($keys as $key) {
$keyMap[$key] = $this->buildKey($key);
}
$values = $this->getValues(array_values($keyMap));
$results = [];
foreach ($keyMap as $key => $newKey) {
$results[$key] = false;
if (isset($values[$newKey])) {
if ($this->serializer === false) {
$results[$key] = $values[$newKey];
} else {
$value = $this->serializer === null ? unserialize($values[$newKey])
: call_user_func($this->serializer[1], $values[$newKey]);
if (is_array($value) && !($value[1] instanceof Dependency && $value[1]->isChanged($this))) {
$results[$key] = $value[0];
}
}
}
}
return $results;
}
/**
* Stores a value identified by a key into cache.
* If the cache already contains such a key, the existing value and
* expiration time will be replaced with the new ones, respectively.
*
* @param mixed $key a key identifying the value to be cached. This can be a simple string or
* a complex data structure consisting of factors representing the key.
* @param mixed $value the value to be cached
* @param int|null $duration default duration in seconds before the cache will expire. If not set,
* default [[defaultDuration]] value is used.
* @param Dependency|null $dependency dependency of the cached item. If the dependency changes,
* the corresponding value in the cache will be invalidated when it is fetched via [[get()]].
* This parameter is ignored if [[serializer]] is false.
* @return bool whether the value is successfully stored into cache
*/
public function set($key, $value, $duration = null, $dependency = null)
{
if ($duration === null) {
$duration = $this->defaultDuration;
}
if ($dependency !== null && $this->serializer !== false) {
$dependency->evaluateDependency($this);
}
if ($this->serializer === null) {
$value = serialize([$value, $dependency]);
} elseif ($this->serializer !== false) {
$value = call_user_func($this->serializer[0], [$value, $dependency]);
}
$key = $this->buildKey($key);
return $this->setValue($key, $value, $duration);
}
/**
* Stores multiple items in cache. Each item contains a value identified by a key.
* If the cache already contains such a key, the existing value and
* expiration time will be replaced with the new ones, respectively.
*
* @param array $items the items to be cached, as key-value pairs.
* @param int|null $duration default duration in seconds before the cache will expire. If not set,
* default [[defaultDuration]] value is used.
* @param Dependency|null $dependency dependency of the cached items. If the dependency changes,
* the corresponding values in the cache will be invalidated when it is fetched via [[get()]].
* This parameter is ignored if [[serializer]] is false.
* @return array array of failed keys
* @deprecated This method is an alias for [[multiSet()]] and will be removed in 2.1.0.
*/
public function mset($items, $duration = null, $dependency = null)
{
return $this->multiSet($items, $duration, $dependency);
}
/**
* Stores multiple items in cache. Each item contains a value identified by a key.
* If the cache already contains such a key, the existing value and
* expiration time will be replaced with the new ones, respectively.
*
* @param array $items the items to be cached, as key-value pairs.
* @param int|null $duration default duration in seconds before the cache will expire. If not set,
* default [[defaultDuration]] value is used.
* @param Dependency|null $dependency dependency of the cached items. If the dependency changes,
* the corresponding values in the cache will be invalidated when it is fetched via [[get()]].
* This parameter is ignored if [[serializer]] is false.
* @return array array of failed keys
* @since 2.0.7
*/
public function multiSet($items, $duration = null, $dependency = null)
{
if ($duration === null) {
$duration = $this->defaultDuration;
}
$data = $this->prepareCacheData($items, $dependency);
return $this->setValues($data, $duration);
}
/**
* Stores multiple items in cache. Each item contains a value identified by a key.
* If the cache already contains such a key, the existing value and expiration time will be preserved.
*
* @param array $items the items to be cached, as key-value pairs.
* @param int $duration default number of seconds in which the cached values will expire. 0 means never expire.
* @param Dependency|null $dependency dependency of the cached items. If the dependency changes,
* the corresponding values in the cache will be invalidated when it is fetched via [[get()]].
* This parameter is ignored if [[serializer]] is false.
* @return array array of failed keys
* @deprecated This method is an alias for [[multiAdd()]] and will be removed in 2.1.0.
*/
public function madd($items, $duration = 0, $dependency = null)
{
return $this->multiAdd($items, $duration, $dependency);
}
/**
* Stores multiple items in cache. Each item contains a value identified by a key.
* If the cache already contains such a key, the existing value and expiration time will be preserved.
*
* @param array $items the items to be cached, as key-value pairs.
* @param int $duration default number of seconds in which the cached values will expire. 0 means never expire.
* @param Dependency|null $dependency dependency of the cached items. If the dependency changes,
* the corresponding values in the cache will be invalidated when it is fetched via [[get()]].
* This parameter is ignored if [[serializer]] is false.
* @return array array of failed keys
* @since 2.0.7
*/
public function multiAdd($items, $duration = 0, $dependency = null)
{
$data = $this->prepareCacheData($items, $dependency);
return $this->addValues($data, $duration);
}
/**
* Prepares data for caching by serializing values and evaluating dependencies.
*
* @param array $items The items to be cached.
* @param mixed $dependency The dependency to be evaluated.
*
* @return array The prepared data for caching.
*/
private function prepareCacheData($items, $dependency)
{
if ($dependency !== null && $this->serializer !== false) {
$dependency->evaluateDependency($this);
}
$data = [];
foreach ($items as $key => $value) {
if ($this->serializer === null) {
$value = serialize([$value, $dependency]);
} elseif ($this->serializer !== false) {
$value = call_user_func($this->serializer[0], [$value, $dependency]);
}
$key = $this->buildKey($key);
$data[$key] = $value;
}
return $data;
}
/**
* Stores a value identified by a key into cache if the cache does not contain this key.
* Nothing will be done if the cache already contains the key.
* @param mixed $key a key identifying the value to be cached. This can be a simple string or
* a complex data structure consisting of factors representing the key.
* @param mixed $value the value to be cached
* @param int $duration the number of seconds in which the cached value will expire. 0 means never expire.
* @param Dependency|null $dependency dependency of the cached item. If the dependency changes,
* the corresponding value in the cache will be invalidated when it is fetched via [[get()]].
* This parameter is ignored if [[serializer]] is false.
* @return bool whether the value is successfully stored into cache
*/
public function add($key, $value, $duration = 0, $dependency = null)
{
if ($dependency !== null && $this->serializer !== false) {
$dependency->evaluateDependency($this);
}
if ($this->serializer === null) {
$value = serialize([$value, $dependency]);
} elseif ($this->serializer !== false) {
$value = call_user_func($this->serializer[0], [$value, $dependency]);
}
$key = $this->buildKey($key);
return $this->addValue($key, $value, $duration);
}
/**
* Deletes a value with the specified key from cache.
* @param mixed $key a key identifying the value to be deleted from cache. This can be a simple string or
* a complex data structure consisting of factors representing the key.
* @return bool if no error happens during deletion
*/
public function delete($key)
{
$key = $this->buildKey($key);
return $this->deleteValue($key);
}
/**
* Deletes all values from cache.
* Be careful of performing this operation if the cache is shared among multiple applications.
* @return bool whether the flush operation was successful.
*/
public function flush()
{
return $this->flushValues();
}
/**
* Retrieves a value from cache with a specified key.
* This method should be implemented by child classes to retrieve the data
* from specific cache storage.
* @param string $key a unique key identifying the cached value
* @return mixed|false the value stored in cache, false if the value is not in the cache or expired. Most often
* value is a string. If you have disabled [[serializer]], it could be something else.
*/
abstract protected function getValue($key);
/**
* Stores a value identified by a key in cache.
* This method should be implemented by child classes to store the data
* in specific cache storage.
* @param string $key the key identifying the value to be cached
* @param mixed $value the value to be cached. Most often it's a string. If you have disabled [[serializer]],
* it could be something else.
* @param int $duration the number of seconds in which the cached value will expire. 0 means never expire.
* @return bool true if the value is successfully stored into cache, false otherwise
*/
abstract protected function setValue($key, $value, $duration);
/**
* Stores a value identified by a key into cache if the cache does not contain this key.
* This method should be implemented by child classes to store the data
* in specific cache storage.
* @param string $key the key identifying the value to be cached
* @param mixed $value the value to be cached. Most often it's a string. If you have disabled [[serializer]],
* it could be something else.
* @param int $duration the number of seconds in which the cached value will expire. 0 means never expire.
* @return bool true if the value is successfully stored into cache, false otherwise
*/
abstract protected function addValue($key, $value, $duration);
/**
* Deletes a value with the specified key from cache
* This method should be implemented by child classes to delete the data from actual cache storage.
* @param string $key the key of the value to be deleted
* @return bool if no error happens during deletion
*/
abstract protected function deleteValue($key);
/**
* Deletes all values from cache.
* Child classes may implement this method to realize the flush operation.
* @return bool whether the flush operation was successful.
*/
abstract protected function flushValues();
/**
* Retrieves multiple values from cache with the specified keys.
* The default implementation calls [[getValue()]] multiple times to retrieve
* the cached values one by one. If the underlying cache storage supports multiget,
* this method should be overridden to exploit that feature.
* @param array $keys a list of keys identifying the cached values
* @return array a list of cached values indexed by the keys
*/
protected function getValues($keys)
{
$results = [];
foreach ($keys as $key) {
$results[$key] = $this->getValue($key);
}
return $results;
}
/**
* Stores multiple key-value pairs in cache.
* The default implementation calls [[setValue()]] multiple times store values one by one. If the underlying cache
* storage supports multi-set, this method should be overridden to exploit that feature.
* @param array $data array where key corresponds to cache key while value is the value stored
* @param int $duration the number of seconds in which the cached values will expire. 0 means never expire.
* @return array array of failed keys
*/
protected function setValues($data, $duration)
{
$failedKeys = [];
foreach ($data as $key => $value) {
if ($this->setValue($key, $value, $duration) === false) {
$failedKeys[] = $key;
}
}
return $failedKeys;
}
/**
* Adds multiple key-value pairs to cache.
* The default implementation calls [[addValue()]] multiple times add values one by one. If the underlying cache
* storage supports multi-add, this method should be overridden to exploit that feature.
* @param array $data array where key corresponds to cache key while value is the value stored.
* @param int $duration the number of seconds in which the cached values will expire. 0 means never expire.
* @return array array of failed keys
*/
protected function addValues($data, $duration)
{
$failedKeys = [];
foreach ($data as $key => $value) {
if ($this->addValue($key, $value, $duration) === false) {
$failedKeys[] = $key;
}
}
return $failedKeys;
}
/**
* Returns whether there is a cache entry with a specified key.
* This method is required by the interface [[\ArrayAccess]].
* @param string $key a key identifying the cached value
* @return bool
*/
#[\ReturnTypeWillChange]
public function offsetExists($key)
{
return $this->get($key) !== false;
}
/**
* Retrieves the value from cache with a specified key.
* This method is required by the interface [[\ArrayAccess]].
* @param string $key a key identifying the cached value
* @return mixed the value stored in cache, false if the value is not in the cache or expired.
*/
#[\ReturnTypeWillChange]
public function offsetGet($key)
{
return $this->get($key);
}
/**
* Stores the value identified by a key into cache.
* If the cache already contains such a key, the existing value will be
* replaced with the new ones. To add expiration and dependencies, use the [[set()]] method.
* This method is required by the interface [[\ArrayAccess]].
* @param string $key the key identifying the value to be cached
* @param mixed $value the value to be cached
*/
#[\ReturnTypeWillChange]
public function offsetSet($key, $value)
{
$this->set($key, $value);
}
/**
* Deletes the value with the specified key from cache
* This method is required by the interface [[\ArrayAccess]].
* @param string $key the key of the value to be deleted
*/
#[\ReturnTypeWillChange]
public function offsetUnset($key)
{
$this->delete($key);
}
/**
* Method combines both [[set()]] and [[get()]] methods to retrieve value identified by a $key,
* or to store the result of $callable execution if there is no cache available for the $key.
*
* Usage example:
*
* ```php
* public function getTopProducts($count = 10) {
* $cache = $this->cache; // Could be Yii::$app->cache
* return $cache->getOrSet(['top-n-products', 'n' => $count], function () use ($count) {
* return Products::find()->mostPopular()->limit($count)->all();
* }, 1000);
* }
* ```
*
* @param mixed $key a key identifying the value to be cached. This can be a simple string or
* a complex data structure consisting of factors representing the key.
* @param callable|\Closure $callable the callable or closure that will be used to generate a value to be cached.
* If you use $callable that can return `false`, then keep in mind that [[getOrSet()]] may work inefficiently
* because the [[yii\caching\Cache::get()]] method uses `false` return value to indicate the data item is not found
* in the cache. Thus, caching of `false` value will lead to unnecessary internal calls.
* @param int|null $duration default duration in seconds before the cache will expire. If not set,
* [[defaultDuration]] value will be used.
* @param Dependency|null $dependency dependency of the cached item. If the dependency changes,
* the corresponding value in the cache will be invalidated when it is fetched via [[get()]].
* This parameter is ignored if [[serializer]] is `false`.
* @return mixed result of $callable execution
* @since 2.0.11
*/
public function getOrSet($key, $callable, $duration = null, $dependency = null)
{
if (($value = $this->get($key)) !== false) {
return $value;
}
$value = call_user_func($callable, $this);
if (!$this->set($key, $value, $duration, $dependency)) {
Yii::warning('Failed to set cache value for key ' . json_encode($key), __METHOD__);
}
return $value;
}
}