# FileCache

> FileCache implements a cache component using files.

[API reference](/docs/api/index.md) › [yii](/docs/api/yii/index.md) › [caching](/docs/api/yii/caching/index.md) › FileCache

| class | `yii\caching\FileCache` |
| --- | --- |
| Extends | [`Cache`](/docs/api/yii/caching/cache/index.md) » [`yii\base\Component`](/docs/api/yii/base/component/index.md) » [`yii\base\BaseObject`](/docs/api/yii/base/baseobject/index.md) |
| Implements | [`CacheInterface`](/docs/api/yii/caching/cacheinterface/index.md), [`yii\base\Configurable`](/docs/api/yii/base/configurable/index.md) |
| Since | 2.0 |
| Source | [`framework/caching/FileCache.php`](https://github.com/yiisoft/yii2/blob/22.0/framework/caching/FileCache.php#L28) |

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`](/docs/api/yii/caching/filecache/index.md#property-cachePath). FileCache will perform garbage collection
automatically to remove expired cache files.

Please refer to [`Cache`](/docs/api/yii/caching/cache/index.md) for common cache operations that are supported by FileCache.

For more details and usage information on Cache, see the [guide article on caching](/docs/guide/caching-overview/index.md).

## Properties

| Property | Type | Description | Defined by |
| --- | --- | --- | --- |
| <span id="property-behaviors"></span>[`$behaviors`](/docs/api/yii/base/component/index.md#property-behaviors) read-only | `array<`[`yii\base\Behavior`](/docs/api/yii/base/behavior/index.md)`<static>>` | List of behaviors attached to this component. | [`yii\base\Component`](/docs/api/yii/base/component/index.md) |
| [`$cacheFileSuffix`](#property-cacheFileSuffix) | `string` | Cache file suffix. Default: `'.bin'`. | `FileCache` |
| [`$cachePath`](#property-cachePath) | `string` | The directory to store cache files. Default: `'@runtime/cache'`. | `FileCache` |
| <span id="property-defaultDuration"></span>[`$defaultDuration`](/docs/api/yii/caching/cache/index.md#property-defaultDuration) | `int` | Default duration in seconds before a cache entry will expire. Default: `0`. Available since 2.0.11. | [`Cache`](/docs/api/yii/caching/cache/index.md) |
| [`$directoryLevel`](#property-directoryLevel) | `int` | The level of sub-directories to store cache files. Default: `1`. | `FileCache` |
| [`$dirMode`](#property-dirMode) | `int` | The permission to be set for newly created directories. Default: `0775`. | `FileCache` |
| [`$fileMode`](#property-fileMode) | `int\|null` | The permission to be set for newly created cache files. Default: `null`. | `FileCache` |
| [`$gcProbability`](#property-gcProbability) | `int` | The probability (parts per million) that garbage collection (GC) should be performed when storing a piece of data in the cache. Default: `10`. | `FileCache` |
| [`$keyPrefix`](#property-keyPrefix) | `string` | A string prefixed to every cache key. Default: `''`. | `FileCache` |
| <span id="property-serializer"></span>[`$serializer`](/docs/api/yii/caching/cache/index.md#property-serializer) | `array\|null\|false` | The functions used to serialize and unserialize cached data. Default: `null`. | [`Cache`](/docs/api/yii/caching/cache/index.md) |

## Methods

| Method | Description | Defined by |
| --- | --- | --- |
| <span id="method-__construct"></span>[`__construct()`](/docs/api/yii/base/baseobject/index.md#method-__construct) | Constructor. | [`yii\base\BaseObject`](/docs/api/yii/base/baseobject/index.md) |
| <span id="method-__call"></span>[`__call()`](/docs/api/yii/base/component/index.md#method-__call) | Calls the named method which is not a class method. | [`yii\base\Component`](/docs/api/yii/base/component/index.md) |
| <span id="method-__clone"></span>[`__clone()`](/docs/api/yii/base/component/index.md#method-__clone) | This method is called after the object is created by cloning an existing one. | [`yii\base\Component`](/docs/api/yii/base/component/index.md) |
| <span id="method-__get"></span>[`__get()`](/docs/api/yii/base/component/index.md#method-__get) | Returns the value of a component property. | [`yii\base\Component`](/docs/api/yii/base/component/index.md) |
| <span id="method-__isset"></span>[`__isset()`](/docs/api/yii/base/component/index.md#method-__isset) | Checks if a property is set, i.e. defined and not null. | [`yii\base\Component`](/docs/api/yii/base/component/index.md) |
| <span id="method-__set"></span>[`__set()`](/docs/api/yii/base/component/index.md#method-__set) | Sets the value of a component property. | [`yii\base\Component`](/docs/api/yii/base/component/index.md) |
| <span id="method-__unset"></span>[`__unset()`](/docs/api/yii/base/component/index.md#method-__unset) | Sets a component property to be null. | [`yii\base\Component`](/docs/api/yii/base/component/index.md) |
| <span id="method-add"></span>[`add()`](/docs/api/yii/caching/cache/index.md#method-add) | Stores a value identified by a key into cache if the cache does not contain this key. | [`Cache`](/docs/api/yii/caching/cache/index.md) |
| <span id="method-attachBehavior"></span>[`attachBehavior()`](/docs/api/yii/base/component/index.md#method-attachBehavior) | Attaches a behavior to this component. | [`yii\base\Component`](/docs/api/yii/base/component/index.md) |
| <span id="method-attachBehaviors"></span>[`attachBehaviors()`](/docs/api/yii/base/component/index.md#method-attachBehaviors) | Attaches a list of behaviors to the component. | [`yii\base\Component`](/docs/api/yii/base/component/index.md) |
| <span id="method-behaviors"></span>[`behaviors()`](/docs/api/yii/base/component/index.md#method-behaviors) | Returns a list of behaviors that this component should behave as. | [`yii\base\Component`](/docs/api/yii/base/component/index.md) |
| <span id="method-buildKey"></span>[`buildKey()`](/docs/api/yii/caching/cache/index.md#method-buildKey) | Builds a normalized cache key from a given key. | [`Cache`](/docs/api/yii/caching/cache/index.md) |
| <span id="method-canGetProperty"></span>[`canGetProperty()`](/docs/api/yii/base/component/index.md#method-canGetProperty) | Returns a value indicating whether a property can be read. | [`yii\base\Component`](/docs/api/yii/base/component/index.md) |
| <span id="method-canSetProperty"></span>[`canSetProperty()`](/docs/api/yii/base/component/index.md#method-canSetProperty) | Returns a value indicating whether a property can be set. | [`yii\base\Component`](/docs/api/yii/base/component/index.md) |
| <span id="method-className"></span>[`className()`](/docs/api/yii/base/baseobject/index.md#method-className) static | Returns the fully qualified name of this class. | [`yii\base\BaseObject`](/docs/api/yii/base/baseobject/index.md) |
| <span id="method-delete"></span>[`delete()`](/docs/api/yii/caching/cache/index.md#method-delete) | Deletes a value with the specified key from cache. | [`Cache`](/docs/api/yii/caching/cache/index.md) |
| <span id="method-detachBehavior"></span>[`detachBehavior()`](/docs/api/yii/base/component/index.md#method-detachBehavior) | Detaches a behavior from the component. | [`yii\base\Component`](/docs/api/yii/base/component/index.md) |
| <span id="method-detachBehaviors"></span>[`detachBehaviors()`](/docs/api/yii/base/component/index.md#method-detachBehaviors) | Detaches all behaviors from the component. | [`yii\base\Component`](/docs/api/yii/base/component/index.md) |
| <span id="method-ensureBehaviors"></span>[`ensureBehaviors()`](/docs/api/yii/base/component/index.md#method-ensureBehaviors) | Makes sure that the behaviors declared in [`behaviors()`](/docs/api/yii/base/component/index.md#method-behaviors) are attached to this component. | [`yii\base\Component`](/docs/api/yii/base/component/index.md) |
| [`exists()`](#method-exists) | Checks whether a specified key exists in the cache. | `FileCache` |
| <span id="method-flush"></span>[`flush()`](/docs/api/yii/caching/cache/index.md#method-flush) | Deletes all values from cache. | [`Cache`](/docs/api/yii/caching/cache/index.md) |
| [`gc()`](#method-gc) | Removes expired cache files. | `FileCache` |
| <span id="method-get"></span>[`get()`](/docs/api/yii/caching/cache/index.md#method-get) | Retrieves a value from cache with a specified key. | [`Cache`](/docs/api/yii/caching/cache/index.md) |
| <span id="method-getBehavior"></span>[`getBehavior()`](/docs/api/yii/base/component/index.md#method-getBehavior) | Returns the named behavior object. | [`yii\base\Component`](/docs/api/yii/base/component/index.md) |
| <span id="method-getBehaviors"></span>[`getBehaviors()`](/docs/api/yii/base/component/index.md#method-getBehaviors) | Returns all behaviors attached to this component. | [`yii\base\Component`](/docs/api/yii/base/component/index.md) |
| <span id="method-getOrSet"></span>[`getOrSet()`](/docs/api/yii/caching/cache/index.md#method-getOrSet) | Method combines both [`set()`](/docs/api/yii/caching/cache/index.md#method-set) and [`get()`](/docs/api/yii/caching/cache/index.md#method-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. | [`Cache`](/docs/api/yii/caching/cache/index.md) |
| <span id="method-hasEventHandlers"></span>[`hasEventHandlers()`](/docs/api/yii/base/component/index.md#method-hasEventHandlers) | Returns a value indicating whether there is any handler attached to the named event. | [`yii\base\Component`](/docs/api/yii/base/component/index.md) |
| <span id="method-hasMethod"></span>[`hasMethod()`](/docs/api/yii/base/component/index.md#method-hasMethod) | Returns a value indicating whether a method is defined. | [`yii\base\Component`](/docs/api/yii/base/component/index.md) |
| <span id="method-hasProperty"></span>[`hasProperty()`](/docs/api/yii/base/component/index.md#method-hasProperty) | Returns a value indicating whether a property is defined for this component. | [`yii\base\Component`](/docs/api/yii/base/component/index.md) |
| [`init()`](#method-init) | Initializes this component by ensuring the existence of the cache path. | `FileCache` |
| <span id="method-multiAdd"></span>[`multiAdd()`](/docs/api/yii/caching/cache/index.md#method-multiAdd) | Stores multiple items in cache. Each item contains a value identified by a key. | [`Cache`](/docs/api/yii/caching/cache/index.md) |
| <span id="method-multiGet"></span>[`multiGet()`](/docs/api/yii/caching/cache/index.md#method-multiGet) | Retrieves multiple values from cache with the specified keys. | [`Cache`](/docs/api/yii/caching/cache/index.md) |
| <span id="method-multiSet"></span>[`multiSet()`](/docs/api/yii/caching/cache/index.md#method-multiSet) | Stores multiple items in cache. Each item contains a value identified by a key. | [`Cache`](/docs/api/yii/caching/cache/index.md) |
| <span id="method-off"></span>[`off()`](/docs/api/yii/base/component/index.md#method-off) | Detaches an existing event handler from this component. | [`yii\base\Component`](/docs/api/yii/base/component/index.md) |
| <span id="method-offsetExists"></span>[`offsetExists()`](/docs/api/yii/caching/cache/index.md#method-offsetExists) | Returns whether there is a cache entry with a specified key. | [`Cache`](/docs/api/yii/caching/cache/index.md) |
| <span id="method-offsetGet"></span>[`offsetGet()`](/docs/api/yii/caching/cache/index.md#method-offsetGet) | Retrieves the value from cache with a specified key. | [`Cache`](/docs/api/yii/caching/cache/index.md) |
| <span id="method-offsetSet"></span>[`offsetSet()`](/docs/api/yii/caching/cache/index.md#method-offsetSet) | Stores the value identified by a key into cache. | [`Cache`](/docs/api/yii/caching/cache/index.md) |
| <span id="method-offsetUnset"></span>[`offsetUnset()`](/docs/api/yii/caching/cache/index.md#method-offsetUnset) | Deletes the value with the specified key from cache This method is required by the interface [`ArrayAccess`](https://www.php.net/manual/en/class.arrayaccess.php). | [`Cache`](/docs/api/yii/caching/cache/index.md) |
| <span id="method-on"></span>[`on()`](/docs/api/yii/base/component/index.md#method-on) | Attaches an event handler to an event. | [`yii\base\Component`](/docs/api/yii/base/component/index.md) |
| <span id="method-set"></span>[`set()`](/docs/api/yii/caching/cache/index.md#method-set) | Stores a value identified by a key into cache. | [`Cache`](/docs/api/yii/caching/cache/index.md) |
| <span id="method-trigger"></span>[`trigger()`](/docs/api/yii/base/component/index.md#method-trigger) | Triggers an event. | [`yii\base\Component`](/docs/api/yii/base/component/index.md) |
| [`addValue()`](#method-addValue) protected | Stores a value identified by a key into cache if the cache does not contain this key. | `FileCache` |
| <span id="method-addValues"></span>[`addValues()`](/docs/api/yii/caching/cache/index.md#method-addValues) protected | Adds multiple key-value pairs to cache. | [`Cache`](/docs/api/yii/caching/cache/index.md) |
| [`deleteValue()`](#method-deleteValue) protected | Deletes a value with the specified key from cache This is the implementation of the method declared in the parent class. | `FileCache` |
| [`flushValues()`](#method-flushValues) protected | Deletes all values from cache. | `FileCache` |
| [`gcRecursive()`](#method-gcRecursive) protected | Recursively removing expired cache files under a directory. | `FileCache` |
| [`getCacheFile()`](#method-getCacheFile) protected | Returns the cache file path given the normalized cache key. | `FileCache` |
| [`getValue()`](#method-getValue) protected | Retrieves a value from cache with a specified key. | `FileCache` |
| <span id="method-getValues"></span>[`getValues()`](/docs/api/yii/caching/cache/index.md#method-getValues) protected | Retrieves multiple values from cache with the specified keys. | [`Cache`](/docs/api/yii/caching/cache/index.md) |
| [`setValue()`](#method-setValue) protected | Stores a value identified by a key in cache. | `FileCache` |
| <span id="method-setValues"></span>[`setValues()`](/docs/api/yii/caching/cache/index.md#method-setValues) protected | Stores multiple key-value pairs in cache. | [`Cache`](/docs/api/yii/caching/cache/index.md) |

## Property details

### $cacheFileSuffix <span id="property-cacheFileSuffix"></span>

```php
public string $cacheFileSuffix = '.bin'
```

Cache file suffix.

Defaults to '.bin'.

### $cachePath <span id="property-cachePath"></span>

```php
public string $cachePath = '@runtime/cache'
```

The directory to store cache files.

You may use [path alias](/docs/guide/concept-aliases/index.md) here.
If not set, it will use the "cache" subdirectory under the application runtime path.

### $directoryLevel <span id="property-directoryLevel"></span>

```php
public int $directoryLevel = 1
```

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.

### $dirMode <span id="property-dirMode"></span>

```php
public int $dirMode = 0775
```

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.

### $fileMode <span id="property-fileMode"></span>

```php
public int|null $fileMode = null
```

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.

### $gcProbability <span id="property-gcProbability"></span>

```php
public int $gcProbability = 10
```

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.

### $keyPrefix <span id="property-keyPrefix"></span>

```php
public string $keyPrefix = ''
```

A string prefixed to every cache key.

This is needed when you store
cache data under the same [`$cachePath`](/docs/api/yii/caching/filecache/index.md#property-cachePath) for different applications to avoid
conflict.

To ensure interoperability, only alphanumeric characters should be used.

## Method details

### exists() <span id="method-exists"></span>

```php
public function exists(mixed $key): bool
```

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()`](/docs/api/yii/caching/cache/index.md#method-get)
may return false while exists returns true.

**Parameters**

| Parameter | Type | Description |
| --- | --- | --- |
| `$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. |

**Returns**

`bool`: True if a value exists in cache, false if the value is not in the cache or expired.

### gc() <span id="method-gc"></span>

```php
public function gc(bool $force = false, bool $expiredOnly = true): mixed
```

Removes expired cache files.

**Parameters**

| Parameter | Type | Description |
| --- | --- | --- |
| `$force` | `bool` | Whether to enforce the garbage collection regardless of [`$gcProbability`](/docs/api/yii/caching/filecache/index.md#property-gcProbability). Defaults to false, meaning the actual deletion happens with the probability as specified by [`$gcProbability`](/docs/api/yii/caching/filecache/index.md#property-gcProbability). |
| `$expiredOnly` | `bool` | Whether to removed expired cache files only. If false, all cache files under [`$cachePath`](/docs/api/yii/caching/filecache/index.md#property-cachePath) will be removed. |

**Returns**

`mixed`

### init() <span id="method-init"></span>

```php
public function init(): mixed
```

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

**Returns**

`mixed`

### addValue() <span id="method-addValue"></span>

```php
protected function addValue(string $key, string $value, int $duration): bool
```

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.

**Parameters**

| Parameter | Type | Description |
| --- | --- | --- |
| `$key` | `string` | The key identifying the value to be cached |
| `$value` | `string` | The value to be cached. Other types (if you have disabled [`$serializer`](/docs/api/yii/caching/cache/index.md#property-serializer)) unable to get is correct in [`getValue()`](/docs/api/yii/caching/filecache/index.md#method-getValue). |
| `$duration` | `int` | The number of seconds in which the cached value will expire. 0 means never expire. |

**Returns**

`bool`: True if the value is successfully stored into cache, false otherwise

### deleteValue() <span id="method-deleteValue"></span>

```php
protected function deleteValue(string $key): bool
```

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

**Parameters**

| Parameter | Type | Description |
| --- | --- | --- |
| `$key` | `string` | The key of the value to be deleted |

**Returns**

`bool`: If no error happens during deletion

### flushValues() <span id="method-flushValues"></span>

```php
protected function flushValues(): bool
```

Deletes all values from cache.

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

**Returns**

`bool`: Whether the flush operation was successful.

### gcRecursive() <span id="method-gcRecursive"></span>

```php
protected function gcRecursive(string $path, bool $expiredOnly): mixed
```

Recursively removing expired cache files under a directory.

This method is mainly used by [`gc()`](/docs/api/yii/caching/filecache/index.md#method-gc).

**Parameters**

| Parameter | Type | Description |
| --- | --- | --- |
| `$path` | `string` | The directory under which expired cache files are removed. |
| `$expiredOnly` | `bool` | Whether to only remove expired cache files. If false, all files under `$path` will be removed. |

**Returns**

`mixed`

### getCacheFile() <span id="method-getCacheFile"></span>

```php
protected function getCacheFile(string $normalizedKey): string
```

Returns the cache file path given the normalized cache key.

**Parameters**

| Parameter | Type | Description |
| --- | --- | --- |
| `$normalizedKey` | `string` | Normalized cache key by [`buildKey()`](/docs/api/yii/caching/cache/index.md#method-buildKey) method |

**Returns**

`string`: The cache file path

### getValue() <span id="method-getValue"></span>

```php
protected function getValue(string $key): string|false
```

Retrieves a value from cache with a specified key.

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

**Parameters**

| Parameter | Type | Description |
| --- | --- | --- |
| `$key` | `string` | A unique key identifying the cached value |

**Returns**

`string|false`: The value stored in cache, false if the value is not in the cache or expired.

### setValue() <span id="method-setValue"></span>

```php
protected function setValue(string $key, string $value, int $duration): bool
```

Stores a value identified by a key in cache.

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

**Parameters**

| Parameter | Type | Description |
| --- | --- | --- |
| `$key` | `string` | The key identifying the value to be cached |
| `$value` | `string` | The value to be cached. Other types (If you have disabled [`$serializer`](/docs/api/yii/caching/cache/index.md#property-serializer)) unable to get is correct in [`getValue()`](/docs/api/yii/caching/filecache/index.md#method-getValue). |
| `$duration` | `int` | The number of seconds in which the cached value will expire. Fewer than or equal to 0 means 1 year expiration time. |

**Returns**

`bool`: True if the value is successfully stored into cache, false otherwise