Store data in a memcached server or memcached cluster. More...

Inherits Wikimedia\ObjectCache\MediumSpecificBagOStuff.

Inherited by Wikimedia\ObjectCache\MemcachedPeclBagOStuff, and Wikimedia\ObjectCache\MemcachedPhpBagOStuff.

Collaboration diagram for Wikimedia\ObjectCache\MemcachedBagOStuff:

[legend]

Public Member Functions

__construct (array $params)

validateKeyEncoding ( $key)

Ensure that a key is safe to use (contains no control characters and no characters above the ASCII range.)

Public Member Functions inherited from Wikimedia\ObjectCache\MediumSpecificBagOStuff

add ( $key, $value, $exptime=0, $flags=0)

Insert an item if it does not already exist.

Parameters

string	$key
mixed	$value
int	$exptime
int	$flags	Bitfield of BagOStuff::WRITE_* constants (since 1.33)

Returns: bool Success (item created)

changeTTL ( $key, $exptime=0, $flags=0)

Change the expiration on a key if it exists.

changeTTLMulti (array $keys, $exptime, $flags=0)

Change the expiration of multiple keys that exist.

delete ( $key, $flags=0)

Delete an item if it exists.For large values set with WRITE_ALLOW_SEGMENTS, this only deletes the placeholder key with the segment list. To delete the underlying blobs, include WRITE_ALLOW_SEGMENTS in the flags for delete() as well. While deleting the segment list key has the effect of functionally deleting the key, it leaves unused blobs in storage.The reason that this is not done automatically, is that to delete underlying blobs, requires first fetching the current segment list. Given that 99% of keys don't use WRITE_ALLOW_SEGMENTS, this would be wasteful.

Parameters

string	$key
int	$flags	Bitfield of BagOStuff::WRITE_* constants

Returns: bool Success (item deleted or not found)

deleteMulti (array $keys, $flags=0)

Delete a batch of items.This does not support WRITE_ALLOW_SEGMENTS to avoid excessive read I/OWRITE_BACKGROUND can be used for bulk deletion where the response is not vital

Parameters

string[]	$keys	List of keys
int	$flags	Bitfield of BagOStuff::WRITE_* constants

Returns: bool Success (items deleted and/or not found)

Since: 1.33

deleteObjectsExpiringBefore ( $timestamp, ?callable $progress=null, $limit=INF, ?string $tag=null)

Delete all objects expiring before a certain date.

Parameters

string \| int	$timestamp	The reference date in MW or TS::UNIX format
callable \| null	$progress	Optional, a function which will be called regularly during long-running operations with the percentage progress as the first parameter. [optional]
int \| float	$limit	Maximum number of keys to delete [default: INF]
string \| null	$tag	Tag to purge a single shard only. This is only supported when server tags are used in configuration.

Returns: bool Success; false if unimplemented

get ( $key, $flags=0)

Get an item with the given key.

getMulti (array $keys, $flags=0)

Get an associative array containing the item for each of the keys that have items.

getQoS ( $flag)

Parameters

int $flag BagOStuff::ATTR_* constant

Returns: int BagOStuff:QOS_* constant

Since: 1.28

getSegmentationSize ()

getSegmentedValueMaxSize ()

incrWithInit ( $key, $exptime, $step=1, $init=null, $flags=0)

Increase the value of the given key (no TTL change) if it exists or create it otherwise.This will create the key with the value $init and TTL $exptime instead if not present. Callers should make sure that both ($init - $step) and $exptime are invariants for all operations to any given key. The value of $init should be at least that of $step.The new value is returned, except if the WRITE_BACKGROUND flag is given, in which case the handler may choose to return true to indicate that the operation has been dispatched.

Parameters

string	$key	Key built via makeKey() or makeGlobalKey()
int	$exptime	Time-to-live (in seconds) or a UNIX timestamp expiration
int	$step	Amount to increase the key value by [default: 1]
int \| null	$init	Value to initialize the key to if it does not exist [default: $step]
int	$flags	Bit field of class WRITE_* constants [optional]

Returns: int|bool New value (or true if asynchronous) on success; false on failure

Since: 1.24

lock ( $key, $timeout=6, $exptime=6, $rclass='')

merge ( $key, callable $callback, $exptime=0, $attempts=10, $flags=0)

Merge changes into the existing cache value (possibly creating a new one)

set ( $key, $value, $exptime=0, $flags=0)

Set an item.

Parameters

string	$key
mixed	$value
int	$exptime	Either an interval in seconds or a unix timestamp for expiry
int	$flags	Bitfield of BagOStuff::WRITE_* constants If setting WRITE_ALLOW_SEGMENTS, remember to also set it in any delete() calls.

Returns: bool Success

setMulti (array $valueByKey, $exptime=0, $flags=0)

Batch insertion/replace.

unlock ( $key)

Release an advisory lock on a key string.

Public Member Functions inherited from Wikimedia\ObjectCache\BagOStuff

getCurrentTime ()

getLastError ( $watchPoint=0)

Get the "last error" registry.

getLogger ()

getScopedLock ( $key, $timeout=6, $exptime=30, $rclass='')

Get a lightweight exclusive self-unlocking lock.

getWithSetCallback ( $key, $exptime, $callback, $flags=0)

Get an item, regenerating and setting it if not found.

isKeyGlobal ( $key)

Check whether a cache key is in the global keyspace.

makeGlobalKey ( $keygroup,... $components)

Make a cache key from the given components, in the "global" keyspace.

makeKey ( $keygroup,... $components)

Make a cache key from the given components, in the default keyspace.

setLogger (LoggerInterface $logger)

setMockTime (&$time)

watchErrors ()

Get a "watch point" token that can be used to get the "last error" to occur after now.

Protected Member Functions

doIncrWithInit ( $key, $exptime, $step, $init, $flags)

Parameters

string	$key
int	$exptime
int	$step
int	$init
int	$flags

Returns: int|bool New value or false on failure

doIncrWithInitAsync ( $key, $exptime, $step, $init)

doIncrWithInitSync ( $key, $exptime, $step, $init)

fixExpiry ( $exptime)

makeKeyInternal ( $keyspace, $components)

Format a cache key.

requireConvertGenericKey ()

Whether ::proxyCall() must re-encode cache keys before calling read/write methods.

stripRouteFromKey ( $key)

validateKeyAndPrependRoute ( $key)

Protected Member Functions inherited from Wikimedia\ObjectCache\MediumSpecificBagOStuff

cas ( $casToken, $key, $value, $exptime=0, $flags=0)

Set an item if the current CAS token matches the provided CAS token.

debug ( $text)

doAdd ( $key, $value, $exptime=0, $flags=0)

Insert an item if it does not already exist.

doCas ( $casToken, $key, $value, $exptime=0, $flags=0)

Set an item if the current CAS token matches the provided CAS token.

doChangeTTL ( $key, $exptime, $flags)

doChangeTTLMulti (array $keys, $exptime, $flags=0)

doDelete ( $key, $flags=0)

Delete an item.

doDeleteMulti (array $keys, $flags=0)

doGet ( $key, $flags=0, &$casToken=null)

Get an item.

doGetMulti (array $keys, $flags=0)

Get an associative array containing the item for each of the keys that have items.

doLock ( $key, $timeout, $exptime)

doSet ( $key, $value, $exptime=0, $flags=0)

Set an item.

doSetMulti (array $data, $exptime=0, $flags=0)

doUnlock ( $key)

getExpirationAsTimestamp ( $exptime)

Convert an optionally relative timestamp to an absolute time.

getExpirationAsTTL ( $exptime)

Convert an optionally absolute expiry time to a relative time.

getSerialized ( $value, $key)

Get the serialized form a value, logging a warning if it involves custom classes.

isInteger ( $value)

Check if a value is an integer.

isRelativeExpiration ( $exptime)

makeLockKey ( $key)

makeValueOrSegmentList ( $key, $value, $exptime, $flags, &$ok)

Make the entry to store at a key (inline or segment list), storing any segments.

mergeViaCas ( $key, callable $callback, $exptime, $attempts, $flags)

resolveSegments ( $key, $mainValue)

Get and reassemble the chunks of blob at the given key.

serialize ( $value)

tokensMatch ( $value, $otherValue)

unserialize ( $value)

updateOpStats (string $op, array $keyInfo)

Protected Member Functions inherited from Wikimedia\ObjectCache\BagOStuff

fieldHasFlags ( $field, $flags)

makeFallbackKey (string $key, int $maxLength)

Re-format a cache key that is too long.

mergeFlagMaps (array $bags)

Merge the flag maps of one or more BagOStuff objects into a "lowest common denominator" map.

proxyCall (string $method, int $arg0Sig, int $resSig, array $genericArgs, BagOStuff $wrapper)

Call a method on behalf of wrapper BagOStuff instance.

setLastError ( $error)

Set the "last error" registry due to a problem encountered during an attempted operation.

Protected Attributes
string	$routingPrefix
	Routing prefix appended to keys during operations.

Protected Attributes inherited from Wikimedia\ObjectCache\MediumSpecificBagOStuff
array< string, array >	$locks = []
	Map of (key => (class LOCK_* constant => value)

float	$maxLockSendDelay = 0.05
	Seconds; maximum expected seconds for a lock ping to reach the backend.

int	$segmentationSize
	Bytes; chunk size of segmented cache values.

int	$segmentedValueMaxSize
	Bytes; maximum total size of a segmented cache value.

const	LOCK_DEPTH = 1

const	LOCK_EXPIRY = 3

const	LOCK_RCLASS = 0

const	LOCK_TIME = 2

const	METRIC_OP_ADD = 'add'

const	METRIC_OP_CAS = 'cas'

const	METRIC_OP_CHANGE_TTL = 'change_ttl'

const	METRIC_OP_DECR = 'decr'

const	METRIC_OP_DELETE = 'delete'

const	METRIC_OP_GET = 'get'

const	METRIC_OP_INCR = 'incr'

const	METRIC_OP_SET = 'set'

const	PASS_BY_REF = -1
	Idiom for doGet() to return extra information by reference.

Protected Attributes inherited from Wikimedia\ObjectCache\BagOStuff
callable null	$asyncHandler

int[]	$attrMap = []
	Map of (BagOStuff:ATTR_* constant => BagOStuff:QOS_* constant)

string	$keyspace
	Default keyspace; used by makeKey()

int	$lastError = self::ERR_NONE
	BagOStuff:ERR_* constant of the last error that occurred.

int	$lastErrorId = 0
	Error event sequence number of the last error that occurred.

LoggerInterface	$logger

StatsFactory	$stats

Additional Inherited Members
Public Attributes inherited from Wikimedia\ObjectCache\BagOStuff
const	ATTR_DURABILITY = 2
	Key in getQoS() for durability of storage writes.

const	ERR_NO_RESPONSE = 1
	Storage operation failed to yield a complete response.

const	ERR_NONE = 0
	Storage operation succeeded, or no operation was performed.

const	ERR_UNEXPECTED = 3
	Storage operation failed due to usage limitations or an I/O error.

const	ERR_UNREACHABLE = 2
	Storage operation could not establish a connection.

const	MAX_CONFLICTS_ONE = 1
	Abort after the first merge conflict.

const	QOS_DURABILITY_DISK = 4
	Storage survives on disk on a best-effort basis (e.g.

const	QOS_DURABILITY_NONE = 1
	Storage is disabled or never saves data, not even temporarily (EmptyBagOStuff).

const	QOS_DURABILITY_RDBMS = 5
	Storage survives on disk with high availability (SqlBagOStuff).

const	QOS_DURABILITY_SCRIPT = 2
	Storage survives in memory until the end of the current request or CLI process (HashBagOStuff).

const	QOS_DURABILITY_SERVICE = 3
	Storage survives in memory until a shared service is restarted (e.g.

const	QOS_UNKNOWN = INF
	Generic "unknown" value; useful for comparisons (always "good enough")

const	READ_LATEST = 1
	Bitfield constants for get()/getMulti(); these are only advisory.

const	READ_VERIFIED = 2
	Promise that the caller handles detection of staleness.

const	WRITE_ALLOW_SEGMENTS = 16
	Allow partitioning of the value if it is a large string.

const	WRITE_BACKGROUND = 64
	If supported, do not block on write operation completion; instead, treat writes as succesful based on whether they could be buffered.

const	WRITE_CACHE_ONLY = 8
	Bitfield constants for set()/merge(); these are only advisory.

Static Protected Attributes inherited from Wikimedia\ObjectCache\BagOStuff
static int	$nextErrorMonitorId = 1
	Next sequence number to use for watch/error events.

Detailed Description

Store data in a memcached server or memcached cluster.

This is a base class for MemcachedPhpBagOStuff and MemcachedPeclBagOStuff.

Definition at line 19 of file MemcachedBagOStuff.php.

Constructor & Destructor Documentation

◆ __construct()

Wikimedia\ObjectCache\MemcachedBagOStuff::__construct ( array $params )

Parameters

array

$params

Additional parameters include:

routingPrefix: a routing prefix of the form "<datacenter>/<cluster>/" used to convey the location/strategy to use for handling keys accessed from this instance. The prefix is prepended to keys during cache operations. The memcached proxy must preserve these prefixes in any responses that include requested keys (e.g. get/gets). The proxy is also assumed to strip the routing prefix from the stored key name, which allows for unprefixed access. This can be used with mcrouter. [optional]

Reimplemented from Wikimedia\ObjectCache\MediumSpecificBagOStuff.

Definition at line 32 of file MemcachedBagOStuff.php.

References Wikimedia\ObjectCache\BagOStuff\ATTR_DURABILITY, and Wikimedia\ObjectCache\BagOStuff\QOS_DURABILITY_SERVICE.

Member Function Documentation

◆ doIncrWithInit()

Wikimedia\ObjectCache\MemcachedBagOStuff::doIncrWithInit	(	$key,
		$exptime,
		$step,
		$init,
		$flags )

protected

Parameters

string	$key
int	$exptime
int	$step
int	$init
int	$flags

Returns: int|bool New value or false on failure

Reimplemented from Wikimedia\ObjectCache\MediumSpecificBagOStuff.

Definition at line 156 of file MemcachedBagOStuff.php.

◆ doIncrWithInitAsync()

Wikimedia\ObjectCache\MemcachedBagOStuff::doIncrWithInitAsync	(	$key,
		$exptime,
		$step,
		$init )

abstractprotected

Parameters

string	$key
int	$exptime
int	$step
int	$init

Returns: bool True on success, false on failure

Reimplemented in Wikimedia\ObjectCache\MemcachedPeclBagOStuff, and Wikimedia\ObjectCache\MemcachedPhpBagOStuff.

◆ doIncrWithInitSync()

Wikimedia\ObjectCache\MemcachedBagOStuff::doIncrWithInitSync	(	$key,
		$exptime,
		$step,
		$init )

abstractprotected

Parameters

string	$key
int	$exptime
int	$step
int	$init

Returns: int|bool New value or false on failure

Reimplemented in Wikimedia\ObjectCache\MemcachedPeclBagOStuff, and Wikimedia\ObjectCache\MemcachedPhpBagOStuff.

◆ fixExpiry()

Wikimedia\ObjectCache\MemcachedBagOStuff::fixExpiry ( $exptime )

protected

Parameters

int | float $exptime

Returns: int

Definition at line 137 of file MemcachedBagOStuff.php.

Referenced by Wikimedia\ObjectCache\MemcachedPhpBagOStuff\doAdd(), Wikimedia\ObjectCache\MemcachedPhpBagOStuff\doCas(), Wikimedia\ObjectCache\MemcachedPhpBagOStuff\doChangeTTL(), Wikimedia\ObjectCache\MemcachedPhpBagOStuff\doIncrWithInitAsync(), Wikimedia\ObjectCache\MemcachedPhpBagOStuff\doIncrWithInitSync(), and Wikimedia\ObjectCache\MemcachedPhpBagOStuff\doSet().

◆ makeKeyInternal()

Wikimedia\ObjectCache\MemcachedBagOStuff::makeKeyInternal	(		$keyspace,
			$components )

protected

Format a cache key.

Since: 1.27

See also: BagOStuff::makeKeyInternal

Parameters

string	$keyspace
string[] \| int[] \| null	$components

Returns: string

Reimplemented from Wikimedia\ObjectCache\BagOStuff.

Definition at line 53 of file MemcachedBagOStuff.php.

References Wikimedia\ObjectCache\BagOStuff\$keyspace, and Wikimedia\ObjectCache\BagOStuff\makeFallbackKey().

◆ requireConvertGenericKey()

Wikimedia\ObjectCache\MemcachedBagOStuff::requireConvertGenericKey ( )

protected

Whether ::proxyCall() must re-encode cache keys before calling read/write methods.

Stability: stable: to override

See also: BagOStuff::makeKeyInternal; BagOStuff::proxyCall

Since: 1.41

Returns: bool

Reimplemented from Wikimedia\ObjectCache\BagOStuff.

Definition at line 75 of file MemcachedBagOStuff.php.

◆ stripRouteFromKey()

Wikimedia\ObjectCache\MemcachedBagOStuff::stripRouteFromKey ( $key )

protected

Parameters

string $key

Returns: string

Definition at line 120 of file MemcachedBagOStuff.php.

Referenced by Wikimedia\ObjectCache\MemcachedPhpBagOStuff\doGetMulti().

◆ validateKeyAndPrependRoute()

Wikimedia\ObjectCache\MemcachedBagOStuff::validateKeyAndPrependRoute ( $key )

protected

Parameters

string $key

Returns: string

Definition at line 101 of file MemcachedBagOStuff.php.

◆ validateKeyEncoding()

Wikimedia\ObjectCache\MemcachedBagOStuff::validateKeyEncoding ( $key )

Ensure that a key is safe to use (contains no control characters and no characters above the ASCII range.)

Parameters

string $key

Returns: string

Exceptions

Exception

Definition at line 88 of file MemcachedBagOStuff.php.

Member Data Documentation

◆ $routingPrefix

string Wikimedia\ObjectCache\MemcachedBagOStuff::$routingPrefix

protected

Routing prefix appended to keys during operations.

Definition at line 21 of file MemcachedBagOStuff.php.

The documentation for this class was generated from the following file:

includes/libs/ObjectCache/MemcachedBagOStuff.php

Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ __construct()

Member Function Documentation

◆ doIncrWithInit()

◆ doIncrWithInitAsync()

◆ doIncrWithInitSync()

◆ fixExpiry()

◆ makeKeyInternal()

◆ requireConvertGenericKey()

◆ stripRouteFromKey()

◆ validateKeyAndPrependRoute()

◆ validateKeyEncoding()

Member Data Documentation

◆ $routingPrefix