No-op implementation that stores nothing. More...

Inherits Wikimedia\ObjectCache\MediumSpecificBagOStuff.

Collaboration diagram for Wikimedia\ObjectCache\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)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

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='')

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

doAdd ( $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

doDelete ( $key, $flags=0)

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

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

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

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

doSet ( $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

Returns: bool Success

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)

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 Wikimedia\ObjectCache\BagOStuff

fieldHasFlags ( $field, $flags)

makeFallbackKey (string $key, int $maxLength)

Re-format a cache key that is too long.

makeKeyInternal ( $keyspace, $components)

Make a cache key for the given keyspace and components.

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.

requireConvertGenericKey ()

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

setLastError ( $error)

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

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.

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

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

Detailed Description

No-op implementation that stores nothing.

Used as placeholder or fallback when disabling caching.

This can be used in configuration via the CACHE_NONE constant.

Definition at line 17 of file EmptyBagOStuff.php.

Constructor & Destructor Documentation

◆ __construct()

Wikimedia\ObjectCache\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

Reimplemented from Wikimedia\ObjectCache\MediumSpecificBagOStuff.

Definition at line 18 of file EmptyBagOStuff.php.

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

Member Function Documentation

◆ doAdd()

Wikimedia\ObjectCache\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 Wikimedia\ObjectCache\MediumSpecificBagOStuff.

Definition at line 42 of file EmptyBagOStuff.php.

◆ doDelete()

Wikimedia\ObjectCache\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 Wikimedia\ObjectCache\MediumSpecificBagOStuff.

Definition at line 37 of file EmptyBagOStuff.php.

◆ doGet()

Wikimedia\ObjectCache\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 Wikimedia\ObjectCache\MediumSpecificBagOStuff.

Definition at line 25 of file EmptyBagOStuff.php.

◆ doIncrWithInit()

Wikimedia\ObjectCache\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 Wikimedia\ObjectCache\MediumSpecificBagOStuff.

Definition at line 47 of file EmptyBagOStuff.php.

◆ doSet()

Wikimedia\ObjectCache\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 Wikimedia\ObjectCache\MediumSpecificBagOStuff.

Definition at line 32 of file EmptyBagOStuff.php.

◆ merge()

Wikimedia\ObjectCache\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 Wikimedia\ObjectCache\MediumSpecificBagOStuff.

Definition at line 53 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

◆ doAdd()

◆ doDelete()

◆ doGet()

◆ doIncrWithInit()

◆ doSet()

◆ merge()