Class CacheEngine

Storage engine for CakePHP caching

Abstract
Namespace: Cake\Cache

Constants summary

string

CHECK_KEY

'key'
string

CHECK_VALUE

'value'

Properties summary

$_config protected

array

Runtime config
$_configInitialized protected

bool

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

array

The default cache configuration is overridden in most cache adapters. These are the keys that are common to all adapters. If overridden, this property is not used.
$_groupPrefix protected

string

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

Method Summary

_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.
add() public

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

Delete all keys from the cache
clearGroup() abstract public

Clears all values belonging to a group. Is up to the implementing engine to decide whether actually delete the keys or just simulate it to achieve the same result.
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() abstract public

Decrement a number under the key and return decremented value
delete() abstract 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() abstract public

Fetches the value for a given 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() abstract public

Increment a number under the key and return incremented value
init() public

Initialize the cache engine
set() abstract public

Persists data in the cache, uniquely referenced by the given key with an optional expiration TTL time.
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

_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.

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() abstract public

clear()

Delete all keys from the cache

Returns

bool

True if the cache was successfully cleared, false otherwise

clearGroup() abstract public

clearGroup(string $group)

Clears all values belonging to a group. Is up to the implementing engine to decide whether actually delete the keys or just simulate it to achieve the same result.

Parameters

string $group: name of the group to be cleared

Returns

bool

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() abstract public

decrement(string $key, int $offset)

Decrement a number under the key and return decremented value

Parameters

string $key: Identifier for the data
int $offset optional: How much to subtract

Returns

int|false

New incremented value, false otherwise

delete() abstract 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() abstract public

get(mixed $key, mixed $default)

Fetches the value for a given key from the cache.

Parameters

string $key: The unique key of this item in the cache.
mixed $default optional: Default value to return if the key does not exist.

Returns

mixed

The value of the item from the cache, or $default in case of cache miss.

Throws

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

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() abstract public

increment(string $key, int $offset)

Increment a number under the key and return incremented value

Parameters

string $key: Identifier for the data
int $offset optional: How much to add

Returns

int|false

New incremented value, false otherwise

init() public

init(array $config)

Initialize the cache engine

Called automatically by the cache frontend. Merge the runtime config with the defaults before use.

Parameters

array $config optional: Associative array of parameters for the engine

Returns

bool

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

set() abstract public

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

Persists data in the cache, uniquely referenced by the given key with an optional expiration TTL time.

Parameters

string $key: The key of the item to store.
mixed $value: The value of the item to store, must be serializable.
\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
MUST be thrown if the $key string is not a legal value.

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

`$_config` protected

Runtime config

Type

array

`$_configInitialized` protected

Whether the config property has already been configured with defaults

Type

bool

`$_defaultConfig` protected

The default cache configuration is overridden in most cache adapters. These are the keys that are common to all adapters. If overridden, this property is not used.

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.
prefix Prefix appended to all entries. Good for when you need to share a keyspace with either another cache config or another application.
warnOnWriteFailures Some engines, such as ApcuEngine, may raise warnings on write failures.

Type

array

`$_groupPrefix` protected

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

Type

string

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https://api.cakephp.org/4.0/class-Cake.Cache.CacheEngine.html