Class MemcachedEngine
Memcached storage engine for cache. Memcached has some limitations in the amount of control you have over expire times far in the future. See MemcachedEngine::write() for more information.
Memcached engine supports binary protocol and igbinary serialization (if memcached extension is compiled with --enable-igbinary). Compressed keys can also be incremented/decremented.
Property Summary
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$_Memcached protected
Memcachedmemcached wrapper.
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$_compiledGroupNames protected
string[] -
$_config protected
arrayRuntime config
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$_configInitialized protected
boolWhether the config property has already been configured with defaults
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$_defaultConfig protected
arrayThe default config used unless overridden by runtime configuration
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$_groupPrefix protected
stringContains the compiled string with all group prefixes to be prepended to every key in this cache engine
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$_serializers protected
arrayList of available serializer engines
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 key for cache backend usage.
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_setOptions() protected
Settings the memcached instance
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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
Increments the group value to simulate deletion of all keys under a group old values will remain in storage until they expire.
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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
Decrements the value of an integer cached key
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delete() public
Delete a key from the cache
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deleteMultiple() public
Delete many keys from the cache at once
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duration() protected
Convert the various expressions of a TTL value into duration in seconds
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ensureValidKey() protected
Ensure the validity of the given cache key.
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ensureValidType() protected
Ensure the validity of the argument type and cache keys.
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get() public
Read a key from the cache
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getConfig() public
Returns the config.
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getConfigOrFail() public
Returns the config for this specific key.
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getMultiple() public
Read many keys from the cache at once
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getOption() public
Read an option value from the memcached connection.
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groups() public
Returns the
group valuefor each of the configured groups If the group initial value was not found, then it initializes the group accordingly. -
has() public
Determines whether an item is present in the cache.
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increment() public
Increments the value of an integer cached key
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init() public
Initialize the Cache Engine
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parseServerString() public
Parses the server address into the host/port. Handles both IPv6 and IPv4 addresses and Unix sockets
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set() public
Write data for key into cache. When using memcached as your cache engine remember that the Memcached pecl extension does not support cache expiry times greater than 30 days in the future. Any duration greater than 30 days will be treated as real Unix time value rather than an offset from current time.
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setConfig() public
Sets the config.
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setMultiple() public
Write many cache entries to the cache at once
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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 $key): voidDeletes a single config key.
Parameters
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string$key Key to delete.
Returns
voidThrows
Cake\Core\Exception\Exceptionif attempting to clobber existing config
_configRead() ¶ protected
_configRead(string|null $key): mixedReads a config key.
Parameters
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string|null$key Key to read.
Returns
mixed_configWrite() ¶ protected
_configWrite(string|array $key, mixed $value, bool|string $merge = false): voidWrites a config key.
Parameters
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string|array$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 $key): stringGenerates a key for cache backend usage.
If the requested key is valid, the group prefix value and engine prefix are applied. Whitespace in keys will be replaced.
Parameters
-
string$key the key passed over
Returns
stringThrows
Cake\Cache\InvalidArgumentExceptionIf key's value is invalid.
_setOptions() ¶ protected
_setOptions(): voidSettings the memcached instance
Returns
voidThrows
InvalidArgumentExceptionWhen the Memcached extension is not built with the desired serializer engine.
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
boolclearGroup() ¶ public
clearGroup(string $group): boolIncrements the group value to simulate deletion of all keys under a group old values will remain in storage until they expire.
Each implementation needs to decide whether actually delete the keys or just augment a group generation value to achieve the same result.
Parameters
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string$group name of the group to be cleared
Returns
boolconfigShallow() ¶ 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 $offset = 1): int|falseDecrements the value of an integer cached key
Parameters
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string$key Identifier for the data
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int$offset optional How much to subtract
Returns
int|falsedelete() ¶ public
delete(string $key): boolDelete a key from the cache
Parameters
-
string$key Identifier for the data
Returns
booldeleteMultiple() ¶ public
deleteMultiple(iterable $keys): boolDelete many keys from the cache at once
Parameters
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iterable$keys An array of identifiers for the data
Returns
boolduration() ¶ protected
duration(DateInterval|int|null $ttl): intConvert the various expressions of a TTL value into duration in seconds
Parameters
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DateInterval|int|null$ttl The TTL value of this item. If null is sent, the driver's default duration will be used.
Returns
intensureValidKey() ¶ protected
ensureValidKey(string $key): voidEnsure the validity of the given cache key.
Parameters
-
string$key Key to check.
Returns
voidThrows
Cake\Cache\InvalidArgumentExceptionWhen the key is not valid.
ensureValidType() ¶ protected
ensureValidType(iterable $iterable, string $check = self::CHECK_VALUE): voidEnsure the validity of the argument type and cache keys.
Parameters
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iterable$iterable The iterable to check.
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string$check optional Whether to check keys or values.
Returns
voidThrows
Cake\Cache\InvalidArgumentExceptionget() ¶ public
get(string $key, mixed $default = null): mixedRead a key from the cache
Parameters
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string$key Identifier for the data
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mixed$default optional Default value to return if the key does not exist.
Returns
mixedgetConfig() ¶ 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:
$this->getConfig('some-key', 'default-value');Parameters
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string|null$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
mixedgetConfigOrFail() ¶ public
getConfigOrFail(string $key): mixedReturns the config for this specific key.
The config value for this key must exist, it can never be null.
Parameters
-
string$key The key to get.
Returns
mixedThrows
InvalidArgumentExceptiongetMultiple() ¶ public
getMultiple(iterable $keys, mixed $default = null): arrayRead many keys from the cache at once
Parameters
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iterable$keys An array of identifiers for the data
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mixed$default optional Default value to return for keys that do not exist.
Returns
arraygetOption() ¶ public
getOption(int $name): string|int|bool|nullRead an option value from the memcached connection.
Parameters
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int$name The option name to read.
Returns
string|int|bool|nullSee Also
groups() ¶ public
groups(): string[]Returns the group value for each of the configured groups
If the group initial value was not found, then it initializes
the group accordingly.
Returns
string[]has() ¶ public
has(string $key): boolDetermines whether an item is present in the cache.
NOTE: It is recommended that has() is only to be used for cache warming type purposes and not to be used within your live applications operations for get/set, as this method is subject to a race condition where your has() will return true and immediately after, another script can remove it making the state of your app out of date.
Parameters
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string$key The cache item key.
Returns
boolThrows
Cake\Cache\InvalidArgumentExceptionIf the $key string is not a legal value.
increment() ¶ public
increment(string $key, int $offset = 1): int|falseIncrements the value of an integer cached key
Parameters
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string$key Identifier for the data
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int$offset optional How much to increment
Returns
int|falseinit() ¶ public
init(array $config = []): boolInitialize the Cache Engine
Called automatically by the cache frontend
Parameters
-
array$config optional array of setting for the engine
Returns
boolThrows
InvalidArgumentExceptionWhen you try use authentication without Memcached compiled with SASL support
parseServerString() ¶ public
parseServerString(string $server): arrayParses the server address into the host/port. Handles both IPv6 and IPv4 addresses and Unix sockets
Parameters
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string$server The server address string.
Returns
arrayset() ¶ public
set(string $key, mixed $value, null|intDateInterval $ttl = null): boolWrite data for key into cache. When using memcached as your cache engine remember that the Memcached pecl extension does not support cache expiry times greater than 30 days in the future. Any duration greater than 30 days will be treated as real Unix time value rather than an offset from current time.
Parameters
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string$key Identifier for the data
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mixed$value Data to be cached
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null|intDateInterval$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
boolSee Also
setConfig() ¶ 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:
$this->setConfig(['one' => 'value', 'another' => 'value']);Parameters
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string|array$key The key to set, or a complete array of configs.
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mixed|null$value optional The value to set.
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bool$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.
setMultiple() ¶ public
setMultiple(iterable $values, null|intDateInterval $ttl = null): boolWrite many cache entries to the cache at once
Parameters
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iterable$values An array of data to be stored in the cache
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null|intDateInterval$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
boolwarning() ¶ 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
voidProperty Detail
$_configInitialized ¶ protected
Whether the config property has already been configured with defaults
Type
bool$_defaultConfig ¶ protected
The default config used unless overridden by runtime configuration
compressWhether to compress datadurationSpecify 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.usernameLogin to access the Memcache serverpasswordPassword to access the Memcache serverpersistentThe name of the persistent connection. All configurations using the same persistent value will share a single underlying connection.prefixPrepended to all entries. Good for when you need to share a keyspace with either another cache config or another application.serializeThe serializer engine used to serialize data. Available engines are 'php', 'igbinary' and 'json'. Beside 'php', the memcached extension must be compiled with the appropriate serializer support.serversString or array of memcached servers. If an array MemcacheEngine will use them as a pool.options- Additional options for the memcached client. Should be an array of option => value. Use the \Memcached::OPT_* constants as keys.
Type
array$_groupPrefix ¶ protected
Contains the compiled string with all group prefixes to be prepended to every key in this cache engine
Type
string$_serializers ¶ protected
List of available serializer engines
Memcached must be compiled with JSON and igbinary support to use these engines
Type
array