Class NullEngine
Null cache engine, all operations return false.
This is used internally for when Cache::disable() has been called.
Property Summary
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$_config protected
arrayRuntime config
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$_configInitialized protected
boolWhether the config property has already been configured with defaults
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$_defaultConfig protected
arrayThe default cache configuration is overridden in most cache adapters. These are the keys that are common to all adapters. If overridden, this property is not used.
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$_groupPrefix protected
stringContains the compiled string with all groups prefixes to be prepended to every key in this cache engine
Method Summary
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_configDelete() protected
Deletes a single config key.
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_configRead() protected
Reads a config key.
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_configWrite() protected
Writes a config key.
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_key() protected
Generates a safe key, taking account of the configured key prefix
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add() public
Add a key to the cache if it does not already exist.
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clear() public
Delete all keys from the cache
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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.
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config() public deprecated
Gets/Sets the config.
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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
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delete() public
Delete a key from the cache
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deleteMany() public
Deletes keys from the cache
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gc() public
Garbage collection
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getConfig() public
Returns the config.
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groups() public
Does whatever initialization for each group is required and returns the
group valuefor 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
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init() public
Initialize the cache engine
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key() public
Generates a safe key for use with cache engine storage engines.
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read() public
Read a key from the cache
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readMany() public
Read multiple keys from the cache
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setConfig() public
Sets the config.
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warning() protected
Cache Engines may trigger warnings if they encounter failures during operation, if option warnOnWriteFailures is set to true.
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write() public
Write value for a key into cache
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writeMany() public
Write data for many keys into cache
Method Detail
_configDelete() ¶ protected
_configDelete(string $key): voidDeletes a single config key.
Parameters
-
string$key Key to delete.
Returns
voidThrows
Cake\Core\Exception\Exceptionif attempting to clobber existing config
_configRead() ¶ protected
_configRead(string|null $key): mixedReads a config key.
Parameters
-
string|null$key Key to read.
Returns
mixed_configWrite() ¶ protected
_configWrite(string|array $key, mixed $value, bool|string $merge = false): voidWrites a config key.
Parameters
-
string|array$key Key to write to.
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mixed$value Value to write.
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bool|string$merge optional True to merge recursively, 'shallow' for simple merge, false to overwrite, defaults to false.
Returns
voidThrows
Cake\Core\Exception\Exceptionif attempting to clobber existing config
_key() ¶ protected
_key(string $key): mixedGenerates a safe key, taking account of the configured key prefix
Parameters
-
string$key the key passed over
Returns
mixedThrows
InvalidArgumentExceptionIf key's value is empty
add() ¶ public
add(string $key, mixed $value): boolAdd a key to the cache if it does not already exist.
Defaults to a non-atomic implementation. Subclasses should prefer atomic implementations.
Parameters
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string$key Identifier for the data.
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mixed$value Data to be cached.
Returns
boolclear() ¶ public
clear(bool $check): boolDelete all keys from the cache
Parameters
-
bool$check
Returns
boolclearGroup() ¶ public
clearGroup(string $group): boolClears all values belonging to a group. Is up to the implementing engine to decide whether actually delete the keys or just simulate it to achieve the same result.
Parameters
-
string$group
Returns
boolconfig() ¶ public
config(string|array|null $key = null, mixed|null $value = null, bool $merge = true): mixedGets/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.
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mixed|null$value optional The value to set.
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bool$merge optional Whether to recursively merge or overwrite existing config, defaults to true.
Returns
mixedThrows
Cake\Core\Exception\ExceptionWhen trying to set a key that is invalid.
configShallow() ¶ public
configShallow(string|array $key, mixed|null $value = null): $thisMerge 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:
$this->configShallow(['one' => 'value', 'another' => 'value']);Parameters
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string|array$key The key to set, or a complete array of configs.
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mixed|null$value optional The value to set.
Returns
$thisdecrement() ¶ public
decrement(string $key, int $offset = 1): bool|intDecrement a number under the key and return decremented value
Parameters
-
string$key -
int$offset optional
Returns
bool|intdelete() ¶ public
delete(string $key): boolDelete a key from the cache
Parameters
-
string$key
Returns
booldeleteMany() ¶ public
deleteMany(array $keys): arrayDeletes keys from the cache
Parameters
-
array$keys
Returns
arraygc() ¶ public
gc(int|null $expires = null): voidGarbage collection
Permanently remove all expired and deleted data
Parameters
-
int|null$expires optional
Returns
voidgetConfig() ¶ public
getConfig(string|null $key = null, mixed $default = null): mixedReturns 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.
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mixed$default optional The return value when the key does not exist.
Returns
mixedgroups() ¶ public
groups(): arrayDoes 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
arrayincrement() ¶ public
increment(string $key, int $offset = 1): bool|intIncrement a number under the key and return incremented value
Parameters
-
string$key -
int$offset optional
Returns
bool|intinit() ¶ public
init(array $config = []): boolInitialize the cache engine
Called automatically by the cache frontend. Merge the runtime config with the defaults before use.
Parameters
-
array$config optional
Returns
boolkey() ¶ public
key(string $key): bool|stringGenerates a safe key for use with cache engine storage engines.
Parameters
-
string$key the key passed over
Returns
bool|stringread() ¶ public
read(string $key): mixedRead a key from the cache
Parameters
-
string$key
Returns
mixedreadMany() ¶ public
readMany(array $keys): arrayRead multiple keys from the cache
Parameters
-
array$keys
Returns
arraysetConfig() ¶ public
setConfig(string|array $key, mixed|null $value = null, bool $merge = true): $thisSets 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.
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mixed|null$value optional The value to set.
-
bool$merge optional Whether to recursively merge or overwrite existing config, defaults to true.
Returns
$thisThrows
Cake\Core\Exception\ExceptionWhen trying to set a key that is invalid.
warning() ¶ protected
warning(string $message): voidCache Engines may trigger warnings if they encounter failures during operation, if option warnOnWriteFailures is set to true.
Parameters
-
string$message The warning message.
Returns
voidwrite() ¶ public
write(string $key, mixed $value): boolWrite value for a key into cache
Parameters
-
string$key -
mixed$value
Returns
boolwriteMany() ¶ public
writeMany(array $data): arrayWrite data for many keys into cache
Parameters
-
array$data
Returns
arrayProperty Detail
$_configInitialized ¶ protected
Whether the config property has already been configured with defaults
Type
bool$_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.
durationSpecify how long items in this cache configuration last.groupsList of groups or 'tags' associated to every key stored in this config. handy for deleting a complete group from cache.prefixPrefix appended to all entries. Good for when you need to share a keyspace with either another cache config or another application.probabilityProbability of hitting a cache gc cleanup. Setting to 0 will disable cache::gc from ever being called automatically.warnOnWriteFailuresSome 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