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.

Namespace: Cake\Cache\Engine

Properties summary

  • $_Memcached protected
    \Memcached

    memcached wrapper.

  • $_compiledGroupNames protected
    string[]
  • $_config protected
    array

    Runtime config

  • $_configInitialized protected
    bool

    Whether the config property has already been configured with defaults

  • $_defaultConfig protected
    array

    The default config used unless overridden by runtime configuration

  • $_groupPrefix protected
    string

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

  • $_serializers protected
    array

    List of available serializer engines

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

  • _parseServerString() protected

    Backwards compatible alias of parseServerString

  • _setOptions() protected

    Settings the memcached instance

  • add() public

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

  • clear() public

    Delete all keys from the cache

  • clearGroup() public

    Increments the group value to simulate deletion of all keys under a group old values will remain in storage until they expire.

  • 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

    Decrements the value of an integer cached key

  • delete() public

    Delete a key from the cache

  • deleteMany() public

    Delete many keys from the cache at once

  • gc() public

    Garbage collection

  • getConfig() public

    Returns the config.

  • getConfigOrFail() public

    Returns the config for this specific key.

  • getOption() public

    Read an option value from the memcached connection.

  • groups() public

    Returns the group value for 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

  • init() public

    Initialize the Cache Engine

  • key() public

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

  • parseServerString() public

    Parses the server address into the host/port. Handles both IPv6 and IPv4 addresses and Unix sockets

  • read() public

    Read a key from the cache

  • readMany() public

    Read many keys from the cache at once

  • 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 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.

  • writeMany() public

    Write many cache entries to the cache at once

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

_parseServerString() protected 

_parseServerString(mixed $server)

Backwards compatible alias of parseServerString

Parameters

string $server

The server address string.

Returns

array

Array containing host, port

_setOptions() protected 

_setOptions()

Settings the memcached instance

Throws

InvalidArgumentException
When the Memcached extension is not built with the desired serializer engine.

add() public 

add(mixed $key, mixed $value)

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

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)

Increments the group value to simulate deletion of all keys under a group old values will remain in storage until they expire.

Parameters

string $group

name of the group to be cleared

Returns

bool

success

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)

Decrements the value of an integer cached key

Parameters

string $key

Identifier for the data

int $offset optional

How much to subtract

Returns

int|false

New decremented 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)

Delete many keys from the cache at once

Parameters

array $keys

An array of identifiers for the data

Returns

array

of 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(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

getOption() public 

getOption(mixed $name)

Read an option value from the memcached connection.

Parameters

string $name

The option name to read.

Returns

string|int|bool|null

groups() public 

groups()

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[]

increment() public 

increment(mixed $key, mixed $offset)

Increments the value of an integer cached key

Parameters

string $key

Identifier for the data

int $offset optional

How much to increment

Returns

int|false

New incremented value, false otherwise

init() public 

init(array $config)

Initialize the Cache Engine

Called automatically by the cache frontend

Parameters

array $config optional

array of setting for the engine

Returns

bool

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

Throws

InvalidArgumentException
When you try use authentication without Memcached compiled with SASL support

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

parseServerString() public 

parseServerString(mixed $server)

Parses the server address into the host/port. Handles both IPv6 and IPv4 addresses and Unix sockets

Parameters

string $server

The server address string.

Returns

array

Array containing host, port

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 many keys from the cache at once

Parameters

array $keys

An array of identifiers for the data

Returns

array

An array containing, for each of the given $keys, the cached data or false if cached data could not be retrieved.

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 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

string $key

Identifier for the data

mixed $value

Data to be cached

Returns

bool

True if the data was successfully cached, false on failure

See Also

https://www.php.net/manual/en/memcached.set.php

writeMany() public 

writeMany(mixed $data)

Write many cache entries to the cache at once

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

$_Memcached protected

memcached wrapper.

Type

\Memcached

$_compiledGroupNames protected

Type

string[]

$_config protected

Runtime config

Type

array

$_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

  • compress Whether to compress data
  • 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.
  • username Login to access the Memcache server
  • password Password to access the Memcache server
  • persistent The name of the persistent connection. All configurations using the same persistent value will share a single underlying connection.
  • prefix Prepended 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.
  • serialize The 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.
  • servers String 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

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https://api.cakephp.org/3.9/class-Cake.Cache.Engine.MemcachedEngine.html