Class NullEngine

Null cache engine, all operations appear to work, but do nothing.

This is used internally for when Cache::disable() has been called.

Namespace: Cake\Cache\Engine

Properties summary

  • $_config protected
    array

    Runtime config

  • 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 groups 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 safe key, taking account of the configured key prefix

  • add() public

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

  • clear() public

    Delete all keys from the cache

  • clearGroup() 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.

  • config() public

    Gets/Sets the config.

  • 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

    Decrement a number under the key and return decremented value

  • delete() public

    Delete a key from the cache

  • deleteMany() public

    Deletes keys from the cache

  • gc() public

    Garbage collection

  • getConfig() public

    Returns the config.

  • getConfigOrFail() public

    Returns the config for this specific key.

  • 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

  • increment() public

    Increment a number under the key and return incremented value

  • init() public

    Initialize the cache engine

  • key() public

    Generates a safe key for use with cache engine storage engines.

  • read() public

    Read a key from the cache

  • readMany() public

    Read multiple keys from the cache

  • setConfig() public

    Sets the config.

  • warning() protected

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

  • write() public

    Write value for a key into cache

  • writeMany() public

    Write data for many keys into cache

Method Detail

_configDelete() protected

_configDelete(mixed $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(mixed $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 safe key, taking account of the configured key prefix

Parameters

string $key

the key passed over

Returns

string

Key

Throws

InvalidArgumentException
If key's value is empty

add() public

add(mixed $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(mixed $check)

Delete all keys from the cache

Parameters

bool $check

if true will check expiration, otherwise delete all

Returns

bool

True if the cache was successfully cleared, false otherwise

clearGroup() public

clearGroup(mixed $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

config() public

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

Gets/Sets the config.

Usage

Reading the whole config:

$this->config();

Reading a specific value:

$this->config('key');

Reading a nested value:

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

Setting a specific value:

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

Setting a nested value:

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

Updating multiple config settings at the same time:

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

Parameters

string|array|null $key optional

The key to get/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

mixed

Config value being read, or the object itself on write operations.

Throws

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

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(mixed $key, mixed $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() 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

deleteMany() public

deleteMany(mixed $keys)

Deletes keys from the cache

Parameters

array $keys

An array of identifiers for the data

Returns

array

For each provided cache key (given back as the array key) true if the value was successfully deleted, false if it didn't exist or couldn't be removed

gc() public

gc(mixed $expires)

Garbage collection

Permanently remove all expired and deleted data

Parameters

int|null $expires optional

[optional] An expires timestamp, invalidating all data before.

getConfig() public

getConfig(mixed $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|null $default optional

The return value when the key does not exist.

Returns

mixed|null

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

getConfigOrFail() public

getConfigOrFail(mixed $key)

Returns the config for this specific key.

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

Parameters

string|null $key

The key to get.

Returns

mixed

Configuration data at the named key

Throws

InvalidArgumentException

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[]

increment() public

increment(mixed $key, mixed $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

key() public

key(mixed $key)

Generates a safe key for use with cache engine storage engines.

Parameters

string $key

the key passed over

Returns

string|false

string key or false

read() public

read(mixed $key)

Read a key from the cache

Parameters

string $key

Identifier for the data

Returns

mixed

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

readMany() public

readMany(mixed $keys)

Read multiple keys from the cache

Parameters

array $keys

An array of identifiers for the data

Returns

array

For each cache key (given as the array key) the cache data associated or false if the data doesn't exist, has expired, or if there was an error fetching it

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.

warning() protected

warning(mixed $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.

write() public

write(mixed $key, mixed $value)

Write value for a key into cache

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

writeMany() public

writeMany(mixed $data)

Write data for many keys into cache

Parameters

array $data

An array of data to be stored in the cache

Returns

array

of bools for each key provided, true if the data was successfully cached, false on failure

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.
  • probability Probability of hitting a cache gc cleanup. Setting to 0 will disable cache::gc from ever being called automatically.
  • warnOnWriteFailures Some engines, such as ApcuEngine, may raise warnings on write failures.

Type

array

$_groupPrefix protected

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

Type

string

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