Inheritance diagram for NearExpiringWANObjectCache:

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Collaboration diagram for NearExpiringWANObjectCache:

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Public Attributes
const	CLOCK_SKEW = 1

Public Attributes inherited from WANObjectCache
const	AGE_NEW = 60
	Never consider performing "popularity" refreshes until a key reaches this age.

const	CHECK_KEY_TTL = self::TTL_YEAR
	Seconds to keep dependency purge keys around.

const	COOLOFF_KEY_PREFIX = 'WANCache:c:'

const	COOLOFF_TTL = 1
	Seconds to no-op key set() calls to avoid large blob I/O stampedes.

const	FLD_FLAGS = 4

const	FLD_HOLDOFF = 5

const	FLD_TIME = 3

const	FLD_TTL = 2

const	FLD_VALUE = 1

const	FLD_VERSION = 0

const	GRACE_TTL_NONE = 0
	Idiom for set()/getWithSetCallback() for "no post-expired grace period".

const	HIT_RATE_HIGH = 1
	Hits/second for a refresh to be expected within the "popularity" window.

const	HOLDOFF_NONE = 0
	Idiom for delete() for "no hold-off".

const	HOLDOFF_TTL = 11
	Seconds to tombstone keys on delete()

const	HOT_TTR = 900
	The time length of the "popularity" refresh window for hot keys.

const	INTERIM_KEY_PREFIX = 'WANCache:i:'

const	INTERIM_KEY_TTL = 1
	Seconds to keep interim value keys for tombstoned keys around.

const	LOCK_TTL = 10
	Seconds to keep lock keys around.

const	LOW_TTL = 30
	Default remaining TTL at which to consider pre-emptive regeneration.

const	MAX_COMMIT_DELAY = 3
	Max time expected to pass between delete() and DB commit finishing.

const	MAX_READ_LAG = 7
	Max replication+snapshot lag before applying TTL_LAGGED or disallowing set()

const	MIN_TIMESTAMP_NONE = 0.0
	Idiom for getWithSetCallback() for "no minimum required as-of timestamp".

const	MUTEX_KEY_PREFIX = 'WANCache:m:'

const	PASS_BY_REF = -1
	Parameter to get()/getMulti() to return extra information by reference.

const	PC_PRIMARY = 'primary:1000'

const	PURGE_VAL_PREFIX = 'PURGED:'

const	RAMPUP_TTL = 30
	Seconds to ramp up to the "popularity" refresh chance after a key is no longer new.

const	RECENT_SET_HIGH_MS = 100
	Max millisecond set() backoff for keys in hold-off (far less than INTERIM_KEY_TTL)

const	RECENT_SET_LOW_MS = 50
	Min millisecond set() backoff for keys in hold-off (far less than INTERIM_KEY_TTL)

const	SET_DELAY_HIGH_MS = 50
	Milliseconds of delay after get() where set() storms are a consideration with 'lockTSE'.

const	STALE_TTL_NONE = 0
	Idiom for set()/getWithSetCallback() for "do not augment the storage medium TTL".

const	TIME_KEY_PREFIX = 'WANCache:t:'

const	TINY_NEGATIVE = -0.000001
	Tiny negative float to use when CTL comes up >= 0 due to clock skew.

const	TINY_POSTIVE = 0.000001
	Tiny positive float to use when using "minTime" to assert an inequality.

const	TSE_NONE = -1
	Idiom for getWithSetCallback() callbacks to 'lockTSE' logic.

const	TTL_LAGGED = 30
	Max TTL to store keys when a data sourced is lagged.

const	TTL_UNCACHEABLE = -1
	Idiom for getWithSetCallback() callbacks to avoid calling set()

const	VALUE_KEY_PREFIX = 'WANCache:v:'

const	VERSION = 1
	Cache format version number.

const	VFLD_DATA = 'WOC:d'

const	VFLD_VERSION = 'WOC:v'

Public Attributes inherited from IExpiringStore
const	ATTR_EMULATION = 1

const	ATTR_SYNCWRITES = 2

const	ERR_NO_RESPONSE = 1

const	ERR_NONE = 0

const	ERR_UNEXPECTED = 3

const	ERR_UNREACHABLE = 2

const	QOS_EMULATION_SQL = 1

const	QOS_SYNCWRITES_BE = 2

const	QOS_SYNCWRITES_NONE = 1

const	QOS_SYNCWRITES_QC = 3

const	QOS_SYNCWRITES_SS = 4

const	QOS_UNKNOWN = INF

const	TTL_DAY = 86400

const	TTL_HOUR = 3600

const	TTL_INDEFINITE = 0

const	TTL_MINUTE = 60

const	TTL_MONTH = 2592000

const	TTL_PROC_LONG = 30

const	TTL_PROC_SHORT = 3

const	TTL_SECOND = 1

const	TTL_WEEK = 604800

const	TTL_YEAR = 31536000

Protected Member Functions
	worthRefreshExpiring ( $curTTL, $lowTTL)
	Check if a key is nearing expiration and thus due for randomized regeneration.

Protected Member Functions inherited from WANObjectCache
	determineKeyClassForStats ( $key)

	doGetWithSetCallback ( $key, $ttl, $callback, array $opts, &$asOf=null)
	Do the actual I/O for getWithSetCallback() when needed.

	getCurrentTime ()

	getInterimValue ( $key, $versioned, $minTime)

	getProcessCache ( $group)

	isAliveOrInGracePeriod ( $curTTL, $graceTTL)
	Check if a key is fresh or in the grace window and thus due for randomized reuse.

	isValid ( $value, $versioned, $asOf, $minTime, $purgeTime=null)
	Check if $value is not false, versioned (if needed), and not older than $minTime (if set)

	makePurgeValue ( $timestamp, $holdoff)

	parsePurgeValue ( $value)

	relayDelete ( $key)
	Do the actual async bus delete of a key.

	relayPurge ( $key, $ttl, $holdoff)
	Do the actual async bus purge of a key.

	resolveCTL ( $value, $curTTL, $curInfo, $touchedCallback)

	resolveTouched ( $value, $lastPurge, $touchedCallback)

	setInterimValue ( $key, $value, $tempTTL, $newAsOf)

	unwrap ( $wrapped, $now)
	Do not use this method outside WANObjectCache.

	worthRefreshPopular ( $asOf, $ageNew, $timeTillRefresh, $now)
	Check if a key is due for randomized regeneration due to its popularity.

	wrap ( $value, $ttl, $now)
	Do not use this method outside WANObjectCache.

Additional Inherited Members
Public Member Functions inherited from WANObjectCache
	__construct (array $params)

	adaptiveTTL ( $mtime, $maxTTL, $minTTL=30, $factor=0.2)
	Get a TTL that is higher for objects that have not changed recently.

	clearLastError ()
	Clear the "last error" registry.

	clearProcessCache ()
	Clear the in-process caches; useful for testing.

	delete ( $key, $ttl=self::HOLDOFF_TTL)
	Purge a key from all datacenters.

	get ( $key, &$curTTL=null, array $checkKeys=[], &$info=null)
	Fetch the value of a key from cache.

	getCheckKeyTime ( $key)
	Fetch the value of a timestamp "check" key.

	getLastError ()
	Get the "last error" registered; clearLastError() should be called manually.

	getMulti (array $keys, &$curTTLs=[], array $checkKeys=[], &$info=null)
	Fetch the value of several keys from cache.

	getMultiCheckKeyTime (array $keys)
	Fetch the values of each timestamp "check" key.

	getMultiWithSetCallback (ArrayIterator $keyedIds, $ttl, callable $callback, array $opts=[])
	Method to fetch multiple cache keys at once with regeneration.

	getMultiWithUnionSetCallback (ArrayIterator $keyedIds, $ttl, callable $callback, array $opts=[])
	Method to fetch/regenerate multiple cache keys at once.

	getQoS ( $flag)

	getWarmupKeyMisses ()

	getWithSetCallback ( $key, $ttl, $callback, array $opts=[])
	Method to fetch/regenerate cache keys.

	makeGlobalKey ( $class, $component=null)

	makeKey ( $class, $component=null)

	makeMultiKeys (array $entities, callable $keyFunc)

	reap ( $key, $purgeTimestamp, &$isStale=false)
	Set a key to soon expire in the local cluster if it pre-dates $purgeTimestamp.

	reapCheckKey ( $key, $purgeTimestamp, &$isStale=false)
	Set a "check" key to soon expire in the local cluster if it pre-dates $purgeTimestamp.

	resetCheckKey ( $key)
	Delete a "check" key from all datacenters, invalidating keys that use it.

	set ( $key, $value, $ttl=self::TTL_INDEFINITE, array $opts=[])
	Set the value of a key in cache.

	setLogger (LoggerInterface $logger)

	setMockTime (&$time)

	touchCheckKey ( $key, $holdoff=self::HOLDOFF_TTL)
	Purge a "check" key from all datacenters, invalidating keys that use it.

	useInterimHoldOffCaching ( $enabled)
	Enable or disable the use of brief caching for tombstoned keys.

Static Public Member Functions inherited from WANObjectCache
static	newEmpty ()
	Get an instance that wraps EmptyBagOStuff.

Static Protected Member Functions inherited from WANObjectCache
static	prefixCacheKeys (array $keys, $prefix)

Protected Attributes inherited from WANObjectCache
callable null	$asyncHandler
	Function that takes a WAN cache callback and runs it later.

BagOStuff	$cache
	The local datacenter cache.

string	$cluster
	Cache cluster name for mcrouter use.

float	$epoch
	Unix timestamp of the oldest possible valid values.

LoggerInterface	$logger

	$mcrouterAware
	@bar bool Whether to use mcrouter key prefixing for routing

MapCacheLRU[]	$processCaches = []
	Map of group PHP instance caches.

string	$region
	Physical region for mcrouter use.

StatsdDataFactoryInterface	$stats

bool	$useInterimHoldOffCaching = true
	Whether to use "interim" caching while keys are tombstoned.

Detailed Description

Definition at line 1855 of file WANObjectCacheTest.php.

Member Function Documentation

◆ worthRefreshExpiring()

NearExpiringWANObjectCache::worthRefreshExpiring	(	$curTTL,
		$lowTTL
	)

protected

Check if a key is nearing expiration and thus due for randomized regeneration.

This returns false if $curTTL >= $lowTTL. Otherwise, the chance of returning true increases steadily from 0% to 100% as the $curTTL moves from $lowTTL to 0 seconds. This handles widely varying levels of cache access traffic.

If $curTTL <= 0 (e.g. already expired), then this returns false.

Parameters

float	$curTTL	Approximate TTL left on the key if present
float	$lowTTL	Consider a refresh when $curTTL is less than this

Returns: bool

Reimplemented from WANObjectCache.

Definition at line 1858 of file WANObjectCacheTest.php.

Member Data Documentation

◆ CLOCK_SKEW

const NearExpiringWANObjectCache::CLOCK_SKEW = 1

Definition at line 1856 of file WANObjectCacheTest.php.

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

tests/phpunit/includes/libs/objectcache/WANObjectCacheTest.php

Public Attributes

Protected Member Functions

Additional Inherited Members

Detailed Description

Member Function Documentation

◆ worthRefreshExpiring()

Member Data Documentation

◆ CLOCK_SKEW