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

Constants summary

  • string
    CHECK_KEY
    'key'
  • string
    CHECK_VALUE
    'value'

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 group 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 key for cache backend usage.

  • _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.

  • 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

  • deleteMultiple() public

    Delete many keys from the cache at once

  • duration() protected

    Convert the various expressions of a TTL value into duration in seconds

  • ensureValidKey() protected

    Ensure the validity of the given cache key.

  • ensureValidType() protected

    Ensure the validity of the argument type and cache keys.

  • get() public

    Read a key from the cache

  • getConfig() public

    Returns the config.

  • getConfigOrFail() public

    Returns the config for this specific key.

  • getMultiple() public

    Read many keys from the cache at once

  • 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.

  • has() public

    Determines whether an item is present in the cache.

  • increment() public

    Increments the value of an integer cached key

  • init() public

    Initialize the Cache Engine

  • parseServerString() public

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

  • 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.

  • setConfig() public

    Sets the config.

  • setMultiple() public

    Write many cache entries to the cache at once

  • 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)

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(?string $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 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

string

Prefixed key with potentially unsafe characters replaced.

Throws

Cake\Cache\InvalidArgumentException
If key's value is invalid.

_setOptions() protected 

_setOptions()

Settings the memcached instance

Throws

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

add() public 

add(string $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()

Delete all keys from the cache

Returns

bool

True if the cache was successfully cleared, false otherwise

clearGroup() public 

clearGroup(string $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

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(string $key, int $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.

deleteMultiple() public 

deleteMultiple(mixed $keys)

Delete many keys from the cache at once

Parameters

iterable $keys

An array of identifiers for the data

Returns

bool

of boolean values that are true if the key was successfully deleted, false if it didn't exist or couldn't be removed.

duration() protected 

duration(mixed $ttl)

Convert the various expressions of a TTL value into duration in seconds

Parameters

\DateInterval|int|null $ttl

The TTL value of this item. If null is sent, the driver's default duration will be used.

Returns

int

ensureValidKey() protected 

ensureValidKey(mixed $key)

Ensure the validity of the given cache key.

Parameters

string $key

Key to check.

Throws

Cake\Cache\InvalidArgumentException
When the key is not valid.

ensureValidType() protected 

ensureValidType(mixed $iterable, string $check)

Ensure the validity of the argument type and cache keys.

Parameters

iterable $iterable

The iterable to check.

string $check optional

Whether to check keys or values.

Throws

Cake\Cache\InvalidArgumentException

get() public 

get(mixed $key, mixed $default)

Read a key from the cache

Parameters

string $key

Identifier for the data

mixed $default optional

Default value to return if the key does not exist.

Returns

mixed

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

getConfig() public 

getConfig(?string $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 $default optional

The return value when the key does not exist.

Returns

mixed

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

getConfigOrFail() public 

getConfigOrFail(string $key)

Returns 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

mixed

Configuration data at the named key

Throws

InvalidArgumentException

getMultiple() public 

getMultiple(mixed $keys, mixed $default)

Read many keys from the cache at once

Parameters

iterable $keys

An array of identifiers for the data

mixed $default optional

Default value to return for keys that do not exist.

Returns

array

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

getOption() public 

getOption(int $name)

Read an option value from the memcached connection.

Parameters

int $name

The option name to read.

Returns

string|int|bool|null

See Also

https://secure.php.net/manual/en/memcached.getoption.php

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[]

has() public 

has(mixed $key)

Determines 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

string $key

The cache item key.

Returns

bool

Throws

Cake\Cache\InvalidArgumentException
If the $key string is not a legal value.

increment() public 

increment(string $key, int $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

parseServerString() public 

parseServerString(string $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

set() public 

set(mixed $key, mixed $value, mixed $ttl)

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

\DateInterval|int|null $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

bool

True if the data was successfully cached, false on failure

See Also

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

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.

setMultiple() public 

setMultiple(mixed $values, mixed $ttl)

Write many cache entries to the cache at once

Parameters

iterable $values

An array of data to be stored in the cache

\DateInterval|int|null $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

bool

Whether the write was successful or not.

warning() protected 

warning(string $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.

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.
  • 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 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

© 2005–present The Cake Software Foundation, Inc.
Licensed under the MIT License.
CakePHP is a registered trademark of Cake Software Foundation, Inc.
We are not endorsed by or affiliated with CakePHP.
https://api.cakephp.org/4.1/class-Cake.Cache.Engine.MemcachedEngine.html