Class FileEngine

File Storage engine for cache. Filestorage is the slowest cache storage to read and write. However, it is good for servers that don't have other storage engine available, or have content which is not performance sensitive.

You can configure a FileEngine cache, using Cache::config()

Namespace: Cake\Cache\Engine

Constants summary

string

CHECK_KEY

'key'
string

CHECK_VALUE

'value'

Properties summary

$_File protected

\SplFileObject|null

Instance of SplFileObject class
$_config protected

array

Runtime config
$_configInitialized protected

bool

Whether the config property has already been configured with defaults
$_defaultConfig protected

array

The default config used unless overridden by runtime configuration
$_groupPrefix protected

string

Contains the compiled string with all group prefixes to be prepended to every key in this cache engine
$_init protected

bool

True unless FileEngine::__active(); fails

Method Summary

_active() protected

Determine if cache directory is writable
_clearDirectory() protected

Used to clear a directory of matching files.
_configDelete() protected

Deletes a single config key.
_configRead() protected

Reads a config key.
_configWrite() protected

Writes a config key.
_key() protected

Generates a key for cache backend usage.
_setKey() protected

Sets the current cache key this class is managing, and creates a writable SplFileObject for the cache file the key is referring to.
add() public

Add a key to the cache if it does not already exist.
clear() public

Delete all values from the cache
clearGroup() public

Recursively deletes all files under any directory named as $group
configShallow() public

Merge provided config with existing config. Unlike config() which does a recursive merge for nested keys, this method does a simple merge.
decrement() public

Not implemented
delete() public

Delete a key from the cache
deleteMultiple() public

Deletes multiple cache items in a single operation.
duration() protected

Convert the various expressions of a TTL value into duration in seconds
ensureValidKey() protected

Ensure the validity of the given cache key.
ensureValidType() protected

Ensure the validity of the argument type and cache keys.
get() public

Read a key from the cache
getConfig() public

Returns the config.
getConfigOrFail() public

Returns the config for this specific key.
getMultiple() public

Obtains multiple cache items by their unique keys.
groups() public

Does whatever initialization for each group is required and returns the group value for each of them, this is the token representing each group in the cache key
has() public

Determines whether an item is present in the cache.
increment() public

Not implemented
init() public

Initialize File Cache Engine
set() public

Write data for key into cache
setConfig() public

Sets the config.
setMultiple() public

Persists a set of key => value pairs in the cache, with an optional TTL.
warning() protected

Cache Engines may trigger warnings if they encounter failures during operation, if option warnOnWriteFailures is set to true.

Method Detail

_active() protected

_active()

Determine if cache directory is writable

Returns

bool

_clearDirectory() protected

_clearDirectory(string $path)

Used to clear a directory of matching files.

Parameters

string $path: The path to search.

_configDelete() protected

_configDelete(string $key)

Deletes a single config key.

Parameters

string $key: Key to delete.

Throws

Cake\Core\Exception\Exception
if attempting to clobber existing config

_configRead() protected

_configRead(?string $key)

Reads a config key.

Parameters

string|null $key: Key to read.

Returns

mixed

_configWrite() protected

_configWrite(mixed $key, mixed $value, mixed $merge)

Writes a config key.

Parameters

string|array $key: Key to write to.
mixed $value: Value to write.
bool|string $merge optional: True to merge recursively, 'shallow' for simple merge, false to overwrite, defaults to false.

Throws

Cake\Core\Exception\Exception
if attempting to clobber existing config

_key() protected

_key(mixed $key)

Generates a key for cache backend usage.

If the requested key is valid, the group prefix value and engine prefix are applied. Whitespace in keys will be replaced.

Parameters

string $key: the key passed over

Returns

string

Prefixed key with potentially unsafe characters replaced.

Throws

Cake\Cache\InvalidArgumentException
If key's value is invalid.

_setKey() protected

_setKey(string $key, bool $createKey)

Sets the current cache key this class is managing, and creates a writable SplFileObject for the cache file the key is referring to.

Parameters

string $key: The key
bool $createKey optional: Whether the key should be created if it doesn't exists, or not

Returns

bool

true if the cache key could be set, false otherwise

add() public

add(string $key, mixed $value)

Add a key to the cache if it does not already exist.

Defaults to a non-atomic implementation. Subclasses should prefer atomic implementations.

Parameters

string $key: Identifier for the data.
mixed $value: Data to be cached.

Returns

bool

True if the data was successfully cached, false on failure.

clear() public

clear()

Delete all values from the cache

Returns

bool

True if the cache was successfully cleared, false otherwise

clearGroup() public

clearGroup(string $group)

Recursively deletes all files under any directory named as $group

Parameters

string $group: The group to clear.

Returns

bool

success

configShallow() public

configShallow(mixed $key, mixed $value)

Merge provided config with existing config. Unlike config() which does a recursive merge for nested keys, this method does a simple merge.

Setting a specific value:

$this->configShallow('key', $value);

Setting a nested value:

$this->configShallow('some.nested.key', $value);

Updating multiple config settings at the same time:

$this->configShallow(['one' => 'value', 'another' => 'value']);

Parameters

string|array $key: The key to set, or a complete array of configs.
mixed|null $value optional: The value to set.

Returns

$this

decrement() public

decrement(string $key, int $offset)

Not implemented

Parameters

string $key: The key to decrement
int $offset optional: The number to offset

Returns

int|false

Throws

LogicException

delete() public

delete(mixed $key)

Delete a key from the cache

Parameters

string $key: Identifier for the data

Returns

bool

True if the value was successfully deleted, false if it didn't exist or couldn't be removed

deleteMultiple() public

deleteMultiple(mixed $keys)

Deletes multiple cache items in a single operation.

Parameters

iterable $keys: A list of string-based keys to be deleted.

Returns

bool

True if the items were successfully removed. False if there was an error.

Throws

Cake\Cache\InvalidArgumentException
If $keys is neither an array nor a Traversable, or if any of the $keys are not a legal value.

duration() protected

duration(mixed $ttl)

Convert the various expressions of a TTL value into duration in seconds

Parameters

\DateInterval|int|null $ttl: The TTL value of this item. If null is sent, the driver's default duration will be used.

Returns

int

ensureValidKey() protected

ensureValidKey(mixed $key)

Ensure the validity of the given cache key.

Parameters

string $key: Key to check.

Throws

Cake\Cache\InvalidArgumentException
When the key is not valid.

ensureValidType() protected

ensureValidType(mixed $iterable, string $check)

Ensure the validity of the argument type and cache keys.

Parameters

iterable $iterable: The iterable to check.
string $check optional: Whether to check keys or values.

Throws

Cake\Cache\InvalidArgumentException

get() public

get(mixed $key, mixed $default)

Read a key from the cache

Parameters

string $key: Identifier for the data
mixed $default optional: Default value to return if the key does not exist.

Returns

mixed

The cached data, or default value if the data doesn't exist, has expired, or if there was an error fetching it

getConfig() public

getConfig(?string $key, mixed $default)

Returns the config.

Usage

Reading the whole config:

$this->getConfig();

Reading a specific value:

$this->getConfig('key');

Reading a nested value:

$this->getConfig('some.nested.key');

Reading with default value:

$this->getConfig('some-key', 'default-value');

Parameters

string|null $key optional: The key to get or null for the whole config.
mixed $default optional: The return value when the key does not exist.

Returns

mixed

Configuration data at the named key or null if the key does not exist.

getConfigOrFail() public

getConfigOrFail(string $key)

Returns the config for this specific key.

The config value for this key must exist, it can never be null.

Parameters

string $key: The key to get.

Returns

mixed

Configuration data at the named key

Throws

InvalidArgumentException

getMultiple() public

getMultiple(mixed $keys, mixed $default)

Obtains multiple cache items by their unique keys.

Parameters

iterable $keys: A list of keys that can obtained in a single operation.
mixed $default optional: Default value to return for keys that do not exist.

Returns

iterable

A list of key value pairs. Cache keys that do not exist or are stale will have $default as value.

Throws

Cake\Cache\InvalidArgumentException
If $keys is neither an array nor a Traversable, or if any of the $keys are not a legal value.

groups() public

groups()

Does whatever initialization for each group is required and returns the group value for each of them, this is the token representing each group in the cache key

Returns

string[]

has() public

has(mixed $key)

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.

Parameters

string $key: The cache item key.

Returns

bool

Throws

Cake\Cache\InvalidArgumentException
If the $key string is not a legal value.

increment() public

increment(string $key, int $offset)

Not implemented

Parameters

string $key: The key to increment
int $offset optional: The number to offset

Returns

int|false

Throws

LogicException

init() public

init(array $config)

Initialize File Cache Engine

Called automatically by the cache frontend.

Parameters

array $config optional: array of setting for the engine

Returns

bool

True if the engine has been successfully initialized, false if not

set() public

set(mixed $key, mixed $value, mixed $ttl)

Write data for key into cache

Parameters

string $key: Identifier for the data
mixed $value: Data to be cached
\DateInterval|int|null $ttl optional: 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.

Returns

bool

True on success and false on failure.

setConfig() public

setConfig(mixed $key, mixed $value, mixed $merge)

Sets the config.

Usage

Setting a specific value:

$this->setConfig('key', $value);

Setting a nested value:

$this->setConfig('some.nested.key', $value);

Updating multiple config settings at the same time:

$this->setConfig(['one' => 'value', 'another' => 'value']);

Parameters

string|array $key: The key to set, or a complete array of configs.
mixed|null $value optional: The value to set.
bool $merge optional: Whether to recursively merge or overwrite existing config, defaults to true.

Returns

$this

Throws

Cake\Core\Exception\Exception
When trying to set a key that is invalid.

setMultiple() public

setMultiple(mixed $values, mixed $ttl)

Persists a set of key => value pairs in the cache, with an optional TTL.

Parameters

iterable $values: A list of key => value pairs for a multiple-set operation.
\DateInterval|int|null $ttl optional: 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.

Returns

bool

True on success and false on failure.

Throws

Cake\Cache\InvalidArgumentException
If $values is neither an array nor a Traversable, or if any of the $values are not a legal value.

warning() protected

warning(string $message)

Cache Engines may trigger warnings if they encounter failures during operation, if option warnOnWriteFailures is set to true.

Parameters

string $message: The warning message.

Property Detail

`$_File` protected

Instance of SplFileObject class

Type

\SplFileObject|null

`$_config` protected

Runtime config

Type

array

`$_configInitialized` protected

Whether the config property has already been configured with defaults

Type

bool

`$_defaultConfig` protected

The default config used unless overridden by runtime configuration

duration Specify how long items in this cache configuration last.
groups List of groups or 'tags' associated to every key stored in this config. handy for deleting a complete group from cache.
lock Used by FileCache. Should files be locked before writing to them?
mask The mask used for created files
path Path to where cachefiles should be saved. Defaults to system's temp dir.
prefix Prepended to all entries. Good for when you need to share a keyspace with either another cache config or another application. cache::gc from ever being called automatically.
serialize Should cache objects be serialized first.

Type

array

`$_groupPrefix` protected

Contains the compiled string with all group prefixes to be prepended to every key in this cache engine

Type

string

`$_init` protected

True unless FileEngine::__active(); fails

Type

bool

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https://api.cakephp.org/4.1/class-Cake.Cache.Engine.FileEngine.html