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

string

CHECK_KEY ¶
```
'key'
```
string

CHECK_VALUE ¶
```
'value'
```

Property Summary

$_Memcached protected

Memcached

memcached wrapper.
$_compiledGroupNames protected

list<string>
$_config protected

array<string, mixed>

Runtime config
$_configInitialized protected

bool

Whether the config property has already been configured with defaults
$_defaultConfig protected

array<string, mixed>

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<string, int>

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): void

Deletes a single config key.

Parameters

string $key: Key to delete.

Returns

void

Throws

Cake\Core\Exception\CakeException
if attempting to clobber existing config

_configRead() ¶ protected

_configRead(string|null $key): mixed

Reads a config key.

Parameters

string|null $key: Key to read.

Returns

mixed

_configWrite() ¶ protected

_configWrite(array<string, mixed>|string $key, mixed $value, string|bool $merge = false): void

Writes a config key.

Parameters

array<string, mixed>|string $key: Key to write to.
mixed $value: Value to write.
string|bool $merge optional: True to merge recursively, 'shallow' for simple merge, false to overwrite, defaults to false.

Returns

void

Throws

Cake\Core\Exception\CakeException
if attempting to clobber existing config

_key() ¶ protected

_key(string $key): string

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

Throws

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

_setOptions() ¶ protected

_setOptions(): void

Settings the memcached instance

Returns

void

Throws

Cake\Cache\Exception\InvalidArgumentException
When the Memcached extension is not built with the desired serializer engine.

add() ¶ public

add(string $key, mixed $value): bool

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

Defaults to a non-atomic implementation. Subclasses should prefer atomic implementations.

Parameters

string $key: Identifier for the data.
mixed $value: Data to be cached.

Returns

bool

clear() ¶ public

clear(): bool

Delete all keys from the cache

Returns

bool

clearGroup() ¶ public

clearGroup(string $group): bool

Increments 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

string $group: name of the group to be cleared

Returns

bool

configShallow() ¶ public

configShallow(array<string, mixed>|string $key, mixed|null $value = null): $this

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

array<string, mixed>|string $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 = 1): int|false

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

delete() ¶ public

delete(string $key): bool

Delete a key from the cache

Parameters

string $key: Identifier for the data

Returns

bool

deleteMultiple() ¶ public

deleteMultiple(iterable<string> $keys): bool

Delete many keys from the cache at once

This is a best effort attempt. If deleting an item would create an error it will be ignored, and all items will be attempted.

Parameters

iterable<string> $keys: An array of identifiers for the data

Returns

bool

duration() ¶ protected

duration(DateInterval|int|null $ttl): int

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): void

Ensure the validity of the given cache key.

Parameters

mixed $key: Key to check.

Returns

void

Throws

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

ensureValidType() ¶ protected

ensureValidType(iterable $iterable, string $check = self::CHECK_VALUE): void

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.

Returns

void

Throws

Cake\Cache\Exception\InvalidArgumentException

get() ¶ public

get(string $key, mixed $default = null): mixed

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

getConfig() ¶ public

getConfig(string|null $key = null, mixed $default = null): mixed

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

getConfigOrFail() ¶ public

getConfigOrFail(string $key): mixed

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

Throws

InvalidArgumentException

getMultiple() ¶ public

getMultiple(iterable<string> $keys, mixed $default = null): iterable<string, mixed>

Read many keys from the cache at once

Parameters

iterable<string> $keys: An array of identifiers for the data
mixed $default optional: Default value to return for keys that do not exist.

Returns

iterable<string, mixed>

getOption() ¶ public

getOption(int $name): string|int|bool|null

Read an option value from the memcached connection.

Parameters

int $name: The option name to read.

Returns

string|int|bool|null

groups() ¶ public

groups(): list<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

list<string>

has() ¶ public

has(string $key): bool

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

increment() ¶ public

increment(string $key, int $offset = 1): int|false

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

init() ¶ public

init(array<string, mixed> $config = []): bool

Initialize the Cache Engine

Called automatically by the cache frontend

Parameters

array<string, mixed> $config optional: array of setting for the engine

Returns

bool

Throws

Cake\Cache\Exception\InvalidArgumentException
When you try use authentication without Memcached compiled with SASL support

parseServerString() ¶ public

parseServerString(string $server): array

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

set() ¶ public

set(string $key, mixed $value, DateInterval|int|null $ttl = null): bool

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

setConfig() ¶ public

setConfig(array<string, mixed>|string $key, mixed|null $value = null, bool $merge = true): $this

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

array<string, mixed>|string $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\CakeException
When trying to set a key that is invalid.

setMultiple() ¶ public

setMultiple(iterable $values, DateInterval|int|null $ttl = null): bool

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

warning() ¶ protected

warning(string $message): void

Cache Engines may trigger warnings if they encounter failures during operation, if option warnOnWriteFailures is set to true.

Parameters

string $message: The warning message.

Returns

void

Property Detail

`$_Memcached` ¶ protected

memcached wrapper.

Type

Memcached

`$_compiledGroupNames` ¶ protected

Type

list<string>

`$_config` ¶ protected

Runtime config

Type

array<string, mixed>

`$_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<string, mixed>

`$_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<string, int>

Namespaces

Class MemcachedEngine

Constants

Property Summary

Method Summary

_configDelete() protected

_configRead() protected

_configWrite() protected

_key() protected

_setOptions() protected

add() public

clear() public

clearGroup() public

configShallow() public

decrement() public

delete() public

deleteMultiple() public

duration() protected

ensureValidKey() protected

ensureValidType() protected

get() public

getConfig() public

getConfigOrFail() public

getMultiple() public

getOption() public

groups() public

has() public

increment() public

init() public

parseServerString() public

set() public

setConfig() public

setMultiple() public

warning() protected

Method Detail

_configDelete() ¶ protected

Parameters

Returns

Throws

_configRead() ¶ protected

Parameters

Returns

_configWrite() ¶ protected

Parameters

Returns

Throws

_key() ¶ protected

Parameters

Returns

Throws

_setOptions() ¶ protected

Returns

Throws

add() ¶ public

Parameters

Returns

clear() ¶ public

Returns

clearGroup() ¶ public

Parameters

Returns

configShallow() ¶ public

Parameters

Returns

decrement() ¶ public

Parameters

Returns

delete() ¶ public

Parameters

Returns

deleteMultiple() ¶ public

Parameters

Returns

duration() ¶ protected

Parameters

Returns

ensureValidKey() ¶ protected

Parameters

Returns

Throws

`$_Memcached` ¶ protected

`$_compiledGroupNames` ¶ protected

`$_config` ¶ protected

`$_configInitialized` ¶ protected

`$_defaultConfig` ¶ protected

`$_groupPrefix` ¶ protected