A BagOStuff object with no objects in it. More...

Collaboration diagram for EmptyBagOStuff:

[legend]

Public Member Functions
	__construct (array $params=[])

	merge ( $key, callable $callback, $exptime=0, $attempts=10, $flags=0)
	Merge changes into the existing cache value (possibly creating a new one)

Public Member Functions inherited from MediumSpecificBagOStuff
	add ( $key, $value, $exptime=0, $flags=0)
	Insert an item if it does not already exist.

	addBusyCallback (callable $workCallback)
	Let a callback be run to avoid wasting time on special blocking calls.

	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.

	deleteMulti (array $keys, $flags=0)
	Batch deletion.

	deleteObjectsExpiringBefore ( $timestamp, callable $progress=null, $limit=INF, string $tag=null)
	Delete all objects expiring before a certain date.

	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)

	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.

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

	makeGlobalKey ( $collection,... $components)
	Make a cache key for the default keyspace and given components.

	makeKey ( $collection,... $components)
	Make a cache key for the global keyspace and given components.

	set ( $key, $value, $exptime=0, $flags=0)
	Set an item.

	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 BagOStuff
	clearLastError ()
	Clear the "last error" registry.

	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.

	registerWrapperInfoForStats (string $prefixComponent, string $statsGroup, callable $collectionCallback)
	Register info about a caching layer class that uses BagOStuff as a backing store.

	setLogger (LoggerInterface $logger)

	setMockTime (&$time)

	setNewPreparedValues (array $valueByKey)
	Stage a set of new key values for storage and estimate the amount of bytes needed.

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

Protected Member Functions
	convertGenericKey ( $key)
	Convert a "generic" reversible cache key into one for this cache.

	doAdd ( $key, $value, $exptime=0, $flags=0)
	Insert an item if it does not already exist.

	doDelete ( $key, $flags=0)
	Delete an item.

	doGet ( $key, $flags=0, &$casToken=null)
	Get an item.

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

	doSet ( $key, $value, $exptime=0, $flags=0)
	Set an item.

	makeKeyInternal ( $keyspace, $components)
	Make a cache key for the given keyspace and components.

Protected Member Functions inherited from MediumSpecificBagOStuff
	cas ( $casToken, $key, $value, $exptime=0, $flags=0)
	Set an item if the current CAS token matches the provided CAS token.

	debug ( $text)

	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)

	doDeleteMulti (array $keys, $flags=0)

	doGetMulti (array $keys, $flags=0)
	Get an associative array containing the item for each of the keys that have items.

	doLock ( $key, $timeout, $exptime)

	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 BagOStuff
	componentsFromGenericKey ( $key)
	Extract the components from a "generic" reversible cache key.

	determineKeyPrefixForStats ( $key)

	fieldHasFlags ( $field, $flags)

	genericKeyFromComponents (... $components)
	At a minimum, there must be a keyspace and collection name component.

	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 that uses "generic" keys.

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

Additional Inherited Members
Public Attributes inherited from BagOStuff
const	MAX_CONFLICTS_ONE = 1
	Abort after the first merge conflict.

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.

const	WRITE_PRUNE_SEGMENTS = 32
	Delete all the segments if the value is partitioned.

Public Attributes inherited from Wikimedia\LightweightObjectStore\StorageAwareness
const	ATTR_DURABILITY = 2
	Durability of writes; see QOS_DURABILITY_* (higher means stronger)

const	ATTR_EMULATION = 1
	Emulation/fallback mode; see QOS_EMULATION_*; higher is better.

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

const	ERR_NONE = 0
	No storage medium error.

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

const	ERR_UNREACHABLE = 2
	Storage medium could not be reached to establish a connection.

const	QOS_DURABILITY_DISK = 4
	Data is saved to disk and writes do not usually block on fsync()

const	QOS_DURABILITY_NONE = 1
	Data is never saved to begin with (blackhole store)

const	QOS_DURABILITY_RDBMS = 5
	Data is saved to disk and writes usually block on fsync(), like a standard RDBMS.

const	QOS_DURABILITY_SCRIPT = 2
	Data is lost at the end of the current web request or CLI script.

const	QOS_DURABILITY_SERVICE = 3
	Data is lost once the service storing the data restarts.

const	QOS_EMULATION_SQL = 1
	Fallback disk-based SQL store.

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

Protected Attributes inherited from 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 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

StatsdDataFactoryInterface	$stats

array< string, array >	$wrapperInfoByPrefix = []
	Cache key processing callbacks and info for metrics.

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

Detailed Description

A BagOStuff object with no objects in it.

Used to provide a no-op object to calling code.

Definition at line 29 of file EmptyBagOStuff.php.

Constructor & Destructor Documentation

◆ __construct()

EmptyBagOStuff::__construct ( array $params = [] )

See also

BagOStuff::__construct() Additional $params options include:

logger: Psr\Log\LoggerInterface instance
reportDupes: Whether to emit warning log messages for all keys that were requested more than once (requires an asyncHandler).
segmentationSize: The chunk size, in bytes, of segmented values. The value should not exceed the maximum size of values in the storage backend, as configured by the site administrator.
segmentedValueMaxSize: The maximum total size, in bytes, of segmented values. This should be configured to a reasonable size give the site traffic and the amount of I/O between application and cache servers that the network can handle.

Parameters

array $params @phpcs:ignore Generic.Files.LineLength

Reimplemented from MediumSpecificBagOStuff.

Definition at line 30 of file EmptyBagOStuff.php.

Member Function Documentation

◆ convertGenericKey()

EmptyBagOStuff::convertGenericKey ( $key )

protected

Convert a "generic" reversible cache key into one for this cache.

See also: BagOStuff::genericKeyFromComponents()

Parameters

string $key Keyspace-prepended list of encoded components as a colon-separated value

Returns: string Keyspace-prepended list of encoded components as a colon-separated value

Reimplemented from MediumSpecificBagOStuff.

Definition at line 68 of file EmptyBagOStuff.php.

◆ doAdd()

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

protected

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

Reimplemented from MediumSpecificBagOStuff.

Definition at line 50 of file EmptyBagOStuff.php.

◆ doDelete()

EmptyBagOStuff::doDelete	(		$key,
			$flags = 0 )

protected

Delete an item.

Parameters

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

Returns: bool True if the item was deleted or not found, false on failure

Reimplemented from MediumSpecificBagOStuff.

Definition at line 46 of file EmptyBagOStuff.php.

◆ doGet()

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

protected

Get an item.

The CAS token should be null if the key does not exist or the value is corrupt

Parameters

string	$key
int	$flags	Bitfield of BagOStuff::READ_* constants [optional]
mixed	&$casToken	CAS token if MediumSpecificBagOStuff::PASS_BY_REF [returned]

Returns: mixed Returns false on failure or if the item does not exist

Reimplemented from MediumSpecificBagOStuff.

Definition at line 36 of file EmptyBagOStuff.php.

◆ doIncrWithInit()

EmptyBagOStuff::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 MediumSpecificBagOStuff.

Definition at line 54 of file EmptyBagOStuff.php.

◆ doSet()

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

protected

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

Returns: bool Success

Reimplemented from MediumSpecificBagOStuff.

Definition at line 42 of file EmptyBagOStuff.php.

◆ makeKeyInternal()

EmptyBagOStuff::makeKeyInternal	(		$keyspace,
			$components )

protected

Make a cache key for the given keyspace and components.

Long components might be converted to respective hashes due to size constraints. In extreme cases, all of them might be combined into a single hash component.

Parameters

string	$keyspace	Keyspace component
string[] \| int[]	$components	Key components (key collection name first)

Returns: string Keyspace-prepended list of encoded components as a colon-separated value

Since: 1.27

Reimplemented from MediumSpecificBagOStuff.

Definition at line 64 of file EmptyBagOStuff.php.

References BagOStuff\$keyspace, and BagOStuff\genericKeyFromComponents().

◆ merge()

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

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

The callback function returns the new value given the current value (which will be false if not present), and takes the arguments: (this BagOStuff, cache key, current value, TTL). The TTL parameter is reference set to $exptime. It can be overridden in the callback. Nothing is stored nor deleted if the callback returns false.

Parameters

string	$key
callable	$callback	Callback method to be executed
int	$exptime	Either an interval in seconds or a unix timestamp for expiry
int	$attempts	The amount of times to attempt a merge in case of failure
int	$flags	Bitfield of BagOStuff::WRITE_* constants

Returns: bool Success

Reimplemented from MediumSpecificBagOStuff.

Definition at line 59 of file EmptyBagOStuff.php.

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

includes/libs/objectcache/EmptyBagOStuff.php

Public Member Functions

Protected Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ __construct()

Member Function Documentation

◆ convertGenericKey()

◆ doAdd()

◆ doDelete()

◆ doGet()

◆ doIncrWithInit()

◆ doSet()

◆ makeKeyInternal()

◆ merge()