# Class yii\caching\FileCache

Inheritance | yii\caching\FileCache » yii\caching\Cache » yii\base\Component » yii\base\BaseObject
Implements | yii\base\Configurable, yii\caching\CacheInterface
Available since version | 2.0
Source Code | https://github.com/yiisoft/yii2/blob/master/framework/caching/FileCache.php

FileCache implements a cache component using files.

For each data value being cached, FileCache will store it in a separate file. The cache files are placed under $cachePath. FileCache will perform garbage collection automatically to remove expired cache files.

Please refer to yii\caching\Cache for common cache operations that are supported by FileCache.

For more details and usage information on Cache, see the guide article on caching.

## Public Properties

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Property | Type | Description | Defined By
--- | --- | --- | ---
$behaviors | yii\base\Behavior[] | List of behaviors attached to this component. This property is read-only. | yii\base\Component
$cacheFileSuffix | string | Cache file suffix. | yii\caching\FileCache
$cachePath | string | The directory to store cache files. | yii\caching\FileCache
$defaultDuration | integer | Default duration in seconds before a cache entry will expire. | yii\caching\Cache
$dirMode | integer | The permission to be set for newly created directories. | yii\caching\FileCache
$directoryLevel | integer | The level of sub-directories to store cache files. | yii\caching\FileCache
$fileMode | integer | The permission to be set for newly created cache files. | yii\caching\FileCache
$gcProbability | integer | The probability (parts per million) that garbage collection (GC) should be performed when storing a piece of data in the cache. | yii\caching\FileCache
$keyPrefix | string | A string prefixed to every cache key. | yii\caching\FileCache
$serializer | null|array|false | The functions used to serialize and unserialize cached data. | yii\caching\Cache

## Public Methods

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Method | Description | Defined By
--- | --- | ---
__call() | Calls the named method which is not a class method. | yii\base\Component
__clone() | This method is called after the object is created by cloning an existing one. | yii\base\Component
__construct() | Constructor. | yii\base\BaseObject
__get() | Returns the value of a component property. | yii\base\Component
__isset() | Checks if a property is set, i.e. defined and not null. | yii\base\Component
__set() | Sets the value of a component property. | yii\base\Component
__unset() | Sets a component property to be null. | yii\base\Component
add() | Stores a value identified by a key into cache if the cache does not contain this key. | yii\caching\Cache
attachBehavior() | Attaches a behavior to this component. | yii\base\Component
attachBehaviors() | Attaches a list of behaviors to the component. | yii\base\Component
behaviors() | Returns a list of behaviors that this component should behave as. | yii\base\Component
buildKey() | Builds a normalized cache key from a given key. | yii\caching\Cache
canGetProperty() | Returns a value indicating whether a property can be read. | yii\base\Component
canSetProperty() | Returns a value indicating whether a property can be set. | yii\base\Component
className() | Returns the fully qualified name of this class. | yii\base\BaseObject
delete() | Deletes a value with the specified key from cache. | yii\caching\Cache
detachBehavior() | Detaches a behavior from the component. | yii\base\Component
detachBehaviors() | Detaches all behaviors from the component. | yii\base\Component
ensureBehaviors() | Makes sure that the behaviors declared in behaviors() are attached to this component. | yii\base\Component
exists() | Checks whether a specified key exists in the cache. | yii\caching\FileCache
flush() | Deletes all values from cache. | yii\caching\Cache
gc() | Removes expired cache files. | yii\caching\FileCache
get() | Retrieves a value from cache with a specified key. | yii\caching\Cache
getBehavior() | Returns the named behavior object. | yii\base\Component
getBehaviors() | Returns all behaviors attached to this component. | yii\base\Component
getOrSet() | 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. | yii\caching\Cache
hasEventHandlers() | Returns a value indicating whether there is any handler attached to the named event. | yii\base\Component
hasMethod() | Returns a value indicating whether a method is defined. | yii\base\Component
hasProperty() | Returns a value indicating whether a property is defined for this component. | yii\base\Component
init() | Initializes this component by ensuring the existence of the cache path. | yii\caching\FileCache
madd() | Stores multiple items in cache. Each item contains a value identified by a key. | yii\caching\Cache
mget() | Retrieves multiple values from cache with the specified keys. | yii\caching\Cache
mset() | Stores multiple items in cache. Each item contains a value identified by a key. | yii\caching\Cache
multiAdd() | Stores multiple items in cache. Each item contains a value identified by a key. | yii\caching\Cache
multiGet() | Retrieves multiple values from cache with the specified keys. | yii\caching\Cache
multiSet() | Stores multiple items in cache. Each item contains a value identified by a key. | yii\caching\Cache
off() | Detaches an existing event handler from this component. | yii\base\Component
offsetExists() | Returns whether there is a cache entry with a specified key. | yii\caching\Cache
offsetGet() | Retrieves the value from cache with a specified key. | yii\caching\Cache
offsetSet() | Stores the value identified by a key into cache. | yii\caching\Cache
offsetUnset() | Deletes the value with the specified key from cache This method is required by the interface ArrayAccess. | yii\caching\Cache
on() | Attaches an event handler to an event. | yii\base\Component
set() | Stores a value identified by a key into cache. | yii\caching\Cache
trigger() | Triggers an event. | yii\base\Component

## Protected Methods

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Method | Description | Defined By
--- | --- | ---
addValue() | Stores a value identified by a key into cache if the cache does not contain this key. | yii\caching\FileCache
addValues() | Adds multiple key-value pairs to cache. | yii\caching\Cache
deleteValue() | Deletes a value with the specified key from cache This is the implementation of the method declared in the parent class. | yii\caching\FileCache
flushValues() | Deletes all values from cache. | yii\caching\FileCache
gcRecursive() | Recursively removing expired cache files under a directory. | yii\caching\FileCache
getCacheFile() | Returns the cache file path given the normalized cache key. | yii\caching\FileCache
getValue() | Retrieves a value from cache with a specified key. | yii\caching\FileCache
getValues() | Retrieves multiple values from cache with the specified keys. | yii\caching\Cache
setValue() | Stores a value identified by a key in cache. | yii\caching\FileCache
setValues() | Stores multiple key-value pairs in cache. | yii\caching\Cache

## Property Details

$cacheFileSuffix public property

Cache file suffix. Defaults to '.bin'.

public string $cacheFileSuffix = '.bin'
$cachePath public property

The directory to store cache files. You may use path alias here. If not set, it will use the "cache" subdirectory under the application runtime path.

public string $cachePath = '@runtime/cache'
$dirMode public property

The permission to be set for newly created directories. This value will be used by PHP chmod() function. No umask will be applied. Defaults to 0775, meaning the directory is read-writable by owner and group, but read-only for other users.

public integer $dirMode = 0775
$directoryLevel public property

The level of sub-directories to store cache files. Defaults to 1. If the system has huge number of cache files (e.g. one million), you may use a bigger value (usually no bigger than 3). Using sub-directories is mainly to ensure the file system is not over burdened with a single directory having too many files.

public integer $directoryLevel = 1
$fileMode public property

The permission to be set for newly created cache files. This value will be used by PHP chmod() function. No umask will be applied. If not set, the permission will be determined by the current environment.

public integer $fileMode = null
$gcProbability public property

The probability (parts per million) that garbage collection (GC) should be performed when storing a piece of data in the cache. Defaults to 10, meaning 0.001% chance. This number should be between 0 and 1000000. A value 0 means no GC will be performed at all.

public integer $gcProbability = 10
$keyPrefix public property

A string prefixed to every cache key. This is needed when you store cache data under the same $cachePath for different applications to avoid conflict.

To ensure interoperability, only alphanumeric characters should be used.

public string $keyPrefix = ''

## Method Details

addValue() protected method

Stores a value identified by a key into cache if the cache does not contain this key.

This is the implementation of the method declared in the parent class.

protected boolean addValue ( $key, $value, $duration )
$key | string | The key identifying the value to be cached
$value | string | The value to be cached. Other types (if you have disabled $serializer) unable to get is correct in getValue().
$duration | integer | The number of seconds in which the cached value will expire. 0 means never expire.
return | boolean | True if the value is successfully stored into cache, false otherwise

deleteValue() protected method

Deletes a value with the specified key from cache This is the implementation of the method declared in the parent class.

protected boolean deleteValue ( $key )
$key | string | The key of the value to be deleted
return | boolean | If no error happens during deletion

exists() public method

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. 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.

public boolean exists ( $key )
$key | mixed | A key identifying the cached value. This can be a simple string or a complex data structure consisting of factors representing the key.
return | boolean | True if a value exists in cache, false if the value is not in the cache or expired.

flushValues() protected method

Deletes all values from cache.

This is the implementation of the method declared in the parent class.

protected boolean flushValues ( )
return | boolean | Whether the flush operation was successful.

gc() public method

Removes expired cache files.

public void gc ( $force = false, $expiredOnly = true )
$force | boolean | Whether to enforce the garbage collection regardless of $gcProbability. Defaults to false, meaning the actual deletion happens with the probability as specified by $gcProbability.
$expiredOnly | boolean | Whether to removed expired cache files only. If false, all cache files under $cachePath will be removed.

gcRecursive() protected method

Recursively removing expired cache files under a directory.

This method is mainly used by gc().

protected void gcRecursive ( $path, $expiredOnly )
$path | string | The directory under which expired cache files are removed.
$expiredOnly | boolean | Whether to only remove expired cache files. If false, all files under `$path` will be removed.

getCacheFile() protected method

Returns the cache file path given the normalized cache key.

protected string getCacheFile ( $normalizedKey )
$normalizedKey | string | Normalized cache key by buildKey() method
return | string | The cache file path

getValue() protected method

Retrieves a value from cache with a specified key.

This is the implementation of the method declared in the parent class.

protected string|false getValue ( $key )
$key | string | A unique key identifying the cached value
return | string|false | The value stored in cache, false if the value is not in the cache or expired.

init() public method

Initializes this component by ensuring the existence of the cache path.

public void init ( )

setValue() protected method

Stores a value identified by a key in cache.

This is the implementation of the method declared in the parent class.

protected boolean setValue ( $key, $value, $duration )
$key | string | The key identifying the value to be cached
$value | string | The value to be cached. Other types (If you have disabled $serializer) unable to get is correct in getValue().
$duration | integer | The number of seconds in which the cached value will expire. 0 means never expire.
return | boolean | True if the value is successfully stored into cache, false otherwise