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.
Main advantage of this Memcached engine over the memcached engine is support of binary protocol, and igbinary serialization (if memcached extension compiled with --enable-igbinary) Compressed keys can also be incremented/decremented
Property Summary
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$_Memcached protected
Memcachedmemcached wrapper.
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$_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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$_groupPrefix protected
stringContains the compiled string with all groups prefixes to be prepended to every key in this cache engine
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$_serializers protected
arrayList of available serializer engines
Method Summary
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_configDelete() protected
Delete a single config key
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_configRead() protected
Read a config variable
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_configWrite() protected
Write a config variable
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_key() protected
Generates a safe key, taking account of the configured key prefix
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_parseServerString() protected
Parses the server address into the host/port. Handles both IPv6 and IPv4 addresses and Unix sockets
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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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config() public
Usage
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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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deleteMany() public
Delete many keys from the cache at once
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gc() public
Garbage collection
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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. -
increment() public
Increments the value of an integer cached key
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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 many keys from the cache at once
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write() 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 never expiring.
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writeMany() public
Write many cache entries to the cache at once
Method Detail
_configDelete() ¶ protected
_configDelete(string $key): voidDelete a single config key
Parameters
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string$key Key to delete.
Returns
voidThrows
Cake\Core\Exception\Exceptionif attempting to clobber existing config
_configRead() ¶ protected
_configRead(string|null $key): mixedRead a config variable
Parameters
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string|null$key Key to read.
Returns
mixed_configWrite() ¶ protected
_configWrite(string|array $key, mixed $value, bool|string $merge = false): voidWrite a config variable
Parameters
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string|array$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 $key): mixedGenerates a safe key, taking account of the configured key prefix
Parameters
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string$key the key passed over
Returns
mixedstring $key or false
Throws
InvalidArgumentExceptionIf key's value is empty
_parseServerString() ¶ protected
_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
arrayArray containing host, port
_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
boolTrue if the data was successfully cached, false on failure.
clear() ¶ public
clear(bool $check): boolDelete all keys from the cache
Parameters
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bool$check If true will check expiration, otherwise delete all.
Returns
boolTrue if the cache was successfully cleared, false otherwise
clearGroup() ¶ public
clearGroup(string $group): boolIncrements the group value to simulate deletion of all keys under a group old values will remain in storage until they expire.
Parameters
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string$group name of the group to be cleared
Returns
boolsuccess
config() ¶ public
config(string|array|null $key = null, mixed|null $value = null, bool $merge = true): mixedUsage
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:
$this->config(['one' => 'value', 'another' => 'value']);Parameters
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string|array|null$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
mixedConfig value being read, or the object itself on write operations.
Throws
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->config('key', $value);Setting a nested value:
$this->config('some.nested.key', $value);Updating multiple config settings at the same time:
$this->config(['one' => 'value', 'another' => 'value']);Parameters
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string|array$key The key to set, or a complete array of configs.
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mixed|null$value optional The value to set.
Returns
$thisThe object itself.
decrement() ¶ public
decrement(string $key, int $offset = 1): bool|intDecrements the value of an integer cached key
Parameters
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string$key Identifier for the data
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int$offset optional How much to subtract
Returns
bool|intNew decremented value, false otherwise
delete() ¶ public
delete(string $key): boolDelete a key from the cache
Parameters
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string$key Identifier for the data
Returns
boolTrue if the value was successfully deleted, false if it didn't exist or couldn't be removed.
deleteMany() ¶ public
deleteMany(array $keys): arrayDelete many keys from the cache at once
Parameters
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array$keys An array of identifiers for the data
Returns
arrayof boolean values that are true if the key was successfully deleted, false if it didn't exist or couldn't be removed.
gc() ¶ public
gc(int|null $expires = null): voidGarbage collection
Permanently remove all expired and deleted data
Parameters
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int|null$expires optional [optional] An expires timestamp, invalidating all data before.
Returns
voidgroups() ¶ public
groups(): arrayReturns the group value for each of the configured groups
If the group initial value was not found, then it initializes
the group accordingly.
Returns
arrayincrement() ¶ public
increment(string $key, int $offset = 1): bool|intIncrements the value of an integer cached key
Parameters
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string$key Identifier for the data
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int$offset optional How much to increment
Returns
bool|intNew incremented value, false otherwise
init() ¶ public
init(array $config = []): boolInitialize the Cache Engine
Called automatically by the cache frontend
Parameters
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array$config optional array of setting for the engine
Returns
boolTrue if the engine has been successfully initialized, false if not
Throws
InvalidArgumentExceptionWhen you try use authentication without Memcached compiled with SASL support
key() ¶ public
key(string $key): bool|stringGenerates a safe key for use with cache engine storage engines.
Parameters
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string$key the key passed over
Returns
bool|stringstring key or false
read() ¶ public
read(string $key): mixedRead a key from the cache
Parameters
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string$key Identifier for the data
Returns
mixedThe cached data, or false if the data doesn't exist, has expired, or if there was an error fetching it.
readMany() ¶ public
readMany(array $keys): arrayRead many keys from the cache at once
Parameters
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array$keys An array of identifiers for the data
Returns
arrayAn array containing, for each of the given $keys, the cached data or false if cached data could not be retrieved.
write() ¶ public
write(string $key, mixed $value): boolWrite data for key into cache. When using memcached as your cache engine remember that the Memcached pecl extension does not support cache expiry times greater than 30 days in the future. Any duration greater than 30 days will be treated as never expiring.
Parameters
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string$key Identifier for the data
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mixed$value Data to be cached
Returns
boolTrue if the data was successfully cached, false on failure
See Also
writeMany() ¶ public
writeMany(array $data): arrayWrite many cache entries to the cache at once
Parameters
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array$data An array of data to be stored in the cache
Returns
arrayof bools for each key provided, true if the data was successfully cached, false on failure
Property 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.probabilityProbability of hitting a cache gc cleanup. Setting to 0 will disable cache::gc from ever being called automatically.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$_groupPrefix ¶ protected
Contains the compiled string with all groups prefixes to be prepended to every key in this cache engine
Type
string$_serializers ¶ protected
List of available serializer engines
Memcached must be compiled with json and igbinary support to use these engines
Type
array