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BagOStuff Class Reference

Class representing a cache/ephemeral data store. More...

Inheritance diagram for BagOStuff:
Collaboration diagram for BagOStuff:

Public Member Functions

 __construct (array $params=[])
 Parameters include: More...
 
 add ( $key, $value, $exptime=0, $flags=0)
 Insert an item if it does not already exist. More...
 
 addBusyCallback (callable $workCallback)
 Let a callback be run to avoid wasting time on special blocking calls. More...
 
 changeTTL ( $key, $exptime=0, $flags=0)
 Change the expiration on a key if it exists. More...
 
 changeTTLMulti (array $keys, $exptime, $flags=0)
 Change the expiration of multiple keys that exist. More...
 
 clearLastError ()
 Clear the "last error" registry. More...
 
 decr ( $key, $value=1, $flags=0)
 Decrease stored value of $key by $value while preserving its TTL. More...
 
 delete ( $key, $flags=0)
 Delete an item. More...
 
 deleteMulti (array $keys, $flags=0)
 Batch deletion. More...
 
 deleteObjectsExpiringBefore ( $timestamp, callable $progress=null, $limit=INF, string $tag=null)
 Delete all objects expiring before a certain date. More...
 
 get ( $key, $flags=0)
 Get an item with the given key. More...
 
 getCurrentTime ()
 
 getLastError ()
 Get the "last error" registered; clearLastError() should be called manually. More...
 
 getLogger ()
 
 getMulti (array $keys, $flags=0)
 Get an associative array containing the item for each of the keys that have items. More...
 
 getQoS ( $flag)
 
 getScopedLock ( $key, $timeout=6, $expiry=30, $rclass='')
 Get a lightweight exclusive self-unlocking lock. More...
 
 getSegmentationSize ()
 
 getSegmentedValueMaxSize ()
 
 getWithSetCallback ( $key, $exptime, $callback, $flags=0)
 Get an item with the given key, regenerating and setting it if not found. More...
 
 incr ( $key, $value=1, $flags=0)
 Increase stored value of $key by $value while preserving its TTL. More...
 
 incrWithInit ( $key, $exptime, $value=1, $init=null, $flags=0)
 Increase the value of the given key (no TTL change) if it exists or create it otherwise. More...
 
 isKeyGlobal ( $key)
 Check whether a cache key is in the global keyspace. More...
 
 lock ( $key, $timeout=6, $exptime=6, $rclass='')
 Acquire an advisory lock on a key string, exclusive to the caller. More...
 
 makeGlobalKey ( $collection,... $components)
 Make a cache key for the default keyspace and given components. More...
 
 makeKey ( $collection,... $components)
 Make a cache key for the global keyspace and given components. More...
 
 makeKeyInternal ( $keyspace, $components)
 Make a cache key for the given keyspace and components. More...
 
 merge ( $key, callable $callback, $exptime=0, $attempts=10, $flags=0)
 Merge changes into the existing cache value (possibly creating a new one) More...
 
 registerWrapperInfoForStats (string $prefixComponent, string $statsGroup, callable $collectionCallback)
 Register info about a caching layer class that uses BagOStuff as a backing store. More...
 
 set ( $key, $value, $exptime=0, $flags=0)
 Set an item. More...
 
 setDebug ( $enabled)
 
 setLogger (LoggerInterface $logger)
 
 setMockTime (&$time)
 
 setMulti (array $valueByKey, $exptime=0, $flags=0)
 Batch insertion/replace. More...
 
 setNewPreparedValues (array $valueByKey)
 Make a "generic" reversible cache key from the given components. More...
 
 unlock ( $key)
 Release an advisory lock on a key string. More...
 

Public Attributes

const READ_LATEST = 1
 Bitfield constants for get()/getMulti(); these are only advisory. More...
 
const READ_VERIFIED = 2
 
const WRITE_ALLOW_SEGMENTS = 16
 
const WRITE_BACKGROUND = 64
 
const WRITE_CACHE_ONLY = 8
 
const WRITE_PRUNE_SEGMENTS = 32
 
const WRITE_SYNC = 4
 Bitfield constants for set()/merge(); these are only advisory. More...
 

Protected Member Functions

 componentsFromGenericKey ( $key)
 Extract the components from a "generic" reversible cache key. More...
 
 convertGenericKey ( $key)
 Convert a "generic" reversible cache key into one for this cache. More...
 
 determineKeyPrefixForStats ( $key)
 
 fieldHasFlags ( $field, $flags)
 
 genericKeyFromComponents (... $components)
 At a minimum, there must be a keyspace and collection name component. More...
 
 mergeFlagMaps (array $bags)
 Merge the flag maps of one or more BagOStuff objects into a "lowest common denominator" map. More...
 
 proxyCall ( $method, $arg0Sig, $resSig, array $genericArgs)
 Call a method on behalf of wrapper BagOStuff instance that uses "generic" keys. More...
 

Protected Attributes

callable null $asyncHandler
 
int[] $attrMap = []
 Map of (ATTR_* class constant => QOS_* class constant) More...
 
bool $debugMode = true
 Whether to send debug log entries to the SPI logger instance. More...
 
string $keyspace
 Default keyspace; used by makeKey() More...
 
LoggerInterface $logger
 
StatsdDataFactoryInterface $stats
 
array< string, array > $wrapperInfoByPrefix = []
 Cache key processing callbacks and info for metrics. More...
 

Private Attributes

float null $wallClockOverride
 
const WRAPPER_COLLECTION_CALLBACK = 1
 Key to the callback that extracts collection names from cache wrapper keys. More...
 
const WRAPPER_STATS_GROUP = 0
 Key to the metric group to use for the relevant cache wrapper. More...
 

Detailed Description

Class representing a cache/ephemeral data store.

This interface is intended to be more or less compatible with the PHP memcached client.

Class instances should be created with an intended access scope for the dataset, such as:

  • a) A single PHP thread on a server (e.g. stored in a PHP variable)
  • b) A single application server (e.g. stored in APC or sqlite)
  • c) All application servers in datacenter (e.g. stored in memcached or mysql)
  • d) All application servers in all datacenters (e.g. stored via mcrouter or dynomite)

Callers should use the proper factory methods that yield BagOStuff instances. Site admins should make sure that the configuration for those factory methods match their access scope. BagOStuff subclasses have widely varying levels of support replication features within and among datacenters.

Subclasses should override the default "segmentationSize" field with an appropriate value. The value should not be larger than what the storage backend (by default) supports. It also should be roughly informed by common performance bottlenecks (e.g. values over a certain size having poor scalability). The same goes for the "segmentedValueMaxSize" member, which limits the maximum size and chunk count (indirectly) of values.

A few notes about data consistency for BagOStuff instances:

  • Read operation methods, e.g. get(), should be synchronous in the local datacenter. When used with READ_LATEST, such operations should reflect any prior writes originating from the local datacenter (e.g. by avoiding replica DBs or invoking quorom reads).
  • Write operation methods, e.g. set(), should be synchronous in the local datacenter, with asynchronous cross-datacenter replication. This replication can be either "best effort" or eventually consistent. When used with WRITE_SYNC, such operations will wait until all datacenters are updated or a timeout occurs. If the write succeeded, then any subsequent get() operations with READ_LATEST, regardless of datacenter, should reflect the changes.
  • Locking operation methods, e.g. lock(), unlock(), and getScopedLock(), should only apply to the local datacenter.
  • Any set of single-key write operation method calls originating from a single datacenter should observe "best effort" linearizability. Any set of single-key write operations using WRITE_SYNC, regardless of the datacenter, should observe "best effort" linearizability. In this context, "best effort" means that consistency holds as long as connectivity is strong, network latency is low, and there are no relevant storage server failures. Per https://en.wikipedia.org/wiki/PACELC_theorem, the store should act as a PA/EL distributed system for these operations.
Stability: stable
to extend

Definition at line 81 of file BagOStuff.php.

Constructor & Destructor Documentation

◆ __construct()

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

Parameters include:

  • keyspace: Keyspace to use for keys in makeKey(). [Default: "local"]
  • asyncHandler: Callable to use for scheduling tasks after the web request ends. In CLI mode, it should run the task immediately. [Default: null]
  • stats: IStatsdDataFactory instance. [optional]
  • logger: Psr\Log\LoggerInterface instance. [optional]
    Parameters
    array$params

Reimplemented in WinCacheBagOStuff, MediumSpecificBagOStuff, EmptyBagOStuff, APCUBagOStuff, and MemcachedBagOStuff.

Definition at line 160 of file BagOStuff.php.

References setLogger().

Member Function Documentation

◆ add()

BagOStuff::add (   $key,
  $value,
  $exptime = 0,
  $flags = 0 
)
abstract

Insert an item if it does not already exist.

Parameters
string$key
mixed$value
int$exptime
int$flagsBitfield of BagOStuff::WRITE_* constants (since 1.33)
Returns
bool Success

Reimplemented in ReplicatedBagOStuff, MultiWriteBagOStuff, MediumSpecificBagOStuff, and CachedBagOStuff.

◆ addBusyCallback()

BagOStuff::addBusyCallback ( callable  $workCallback)
abstract

Let a callback be run to avoid wasting time on special blocking calls.

The callbacks may or may not be called ever, in any particular order. They are likely to be invoked when something WRITE_SYNC is used used. They should follow a caching pattern as shown below, so that any code using the work will get it's result no matter what happens.

$result = null;
$workCallback = function () use ( &$result ) {
if ( !$result ) {
$result = ....
}
return $result;
}
Parameters
callable$workCallback
Since
1.28

Reimplemented in ReplicatedBagOStuff, MultiWriteBagOStuff, MediumSpecificBagOStuff, and CachedBagOStuff.

◆ changeTTL()

BagOStuff::changeTTL (   $key,
  $exptime = 0,
  $flags = 0 
)
abstract

Change the expiration on a key if it exists.

If an expiry in the past is given then the key will immediately be expired

For large values written using WRITE_ALLOW_SEGMENTS, this only changes the TTL of the main segment list key. While lowering the TTL of the segment list key has the effect of functionally lowering the TTL of the key, it might leave unused blobs in cache for longer. Raising the TTL of such keys is not effective, since the expiration of a single segment key effectively expires the entire value.

Parameters
string$key
int$exptimeTTL or UNIX timestamp
int$flagsBitfield of BagOStuff::WRITE_* constants (since 1.33)
Returns
bool Success Returns false on failure or if the item does not exist
Since
1.28

Reimplemented in ReplicatedBagOStuff, MultiWriteBagOStuff, MediumSpecificBagOStuff, and CachedBagOStuff.

◆ changeTTLMulti()

BagOStuff::changeTTLMulti ( array  $keys,
  $exptime,
  $flags = 0 
)
abstract

Change the expiration of multiple keys that exist.

See also
BagOStuff::changeTTL()
Parameters
string[]$keysList of keys
int$exptimeTTL or UNIX timestamp
int$flagsBitfield of BagOStuff::WRITE_* constants (since 1.33)
Returns
bool Success
Since
1.34

Reimplemented in ReplicatedBagOStuff, MultiWriteBagOStuff, MediumSpecificBagOStuff, and CachedBagOStuff.

◆ clearLastError()

BagOStuff::clearLastError ( )
abstract

Clear the "last error" registry.

Since
1.23

Reimplemented in ReplicatedBagOStuff, MultiWriteBagOStuff, MediumSpecificBagOStuff, and CachedBagOStuff.

◆ componentsFromGenericKey()

BagOStuff::componentsFromGenericKey (   $key)
finalprotected

Extract the components from a "generic" reversible cache key.

See also
BagOStuff::genericKeyFromComponents()
Parameters
string$keyKeyspace-prepended list of encoded components as a colon-separated value
Returns
string[] Key components for keyspace, collection name, and IDs
Since
1.35

Definition at line 702 of file BagOStuff.php.

◆ convertGenericKey()

BagOStuff::convertGenericKey (   $key)
abstractprotected

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

See also
BagOStuff::genericKeyFromComponents()
Parameters
string$keyKeyspace-prepended list of encoded components as a colon-separated value
Returns
string Keyspace-prepended list of encoded components as a colon-separated value

Reimplemented in RESTBagOStuff, ReplicatedBagOStuff, RedisBagOStuff, MultiWriteBagOStuff, MediumSpecificBagOStuff, HashBagOStuff, EmptyBagOStuff, CachedBagOStuff, and APCUBagOStuff.

Referenced by proxyCall().

◆ decr()

BagOStuff::decr (   $key,
  $value = 1,
  $flags = 0 
)
abstract

Decrease stored value of $key by $value while preserving its TTL.

Parameters
string$key
int$valueValue to subtract from $key (default: 1) [optional]
int$flagsBit field of class WRITE_* constants [optional]
Returns
int|bool New value or false on failure

Reimplemented in SqlBagOStuff, WinCacheBagOStuff, RESTBagOStuff, ReplicatedBagOStuff, RedisBagOStuff, MultiWriteBagOStuff, MemcachedPhpBagOStuff, MemcachedPeclBagOStuff, HashBagOStuff, EmptyBagOStuff, CachedBagOStuff, and APCUBagOStuff.

◆ delete()

BagOStuff::delete (   $key,
  $flags = 0 
)
abstract

Delete an item.

For large values written using WRITE_ALLOW_SEGMENTS, this only deletes the main segment list key unless WRITE_PRUNE_SEGMENTS is in the flags. While deleting the segment list key has the effect of functionally deleting the key, it leaves unused blobs in cache.

Parameters
string$key
Returns
bool True if the item was deleted or not found, false on failure
Parameters
int$flagsBitfield of BagOStuff::WRITE_* constants

Reimplemented in ReplicatedBagOStuff, MultiWriteBagOStuff, MediumSpecificBagOStuff, and CachedBagOStuff.

◆ deleteMulti()

BagOStuff::deleteMulti ( array  $keys,
  $flags = 0 
)
abstract

Batch deletion.

This does not support WRITE_ALLOW_SEGMENTS to avoid excessive read I/O

WRITE_BACKGROUND can be used for bulk deletion where the response is not vital

Parameters
string[]$keysList of keys
int$flagsBitfield of BagOStuff::WRITE_* constants
Returns
bool Success
Since
1.33

Reimplemented in ReplicatedBagOStuff, MultiWriteBagOStuff, MediumSpecificBagOStuff, and CachedBagOStuff.

◆ deleteObjectsExpiringBefore()

BagOStuff::deleteObjectsExpiringBefore (   $timestamp,
callable  $progress = null,
  $limit = INF,
string  $tag = null 
)
abstract

Delete all objects expiring before a certain date.

Parameters
string | int$timestampThe reference date in MW or TS_UNIX format
callable | null$progressOptional, a function which will be called regularly during long-running operations with the percentage progress as the first parameter. [optional]
int$limitMaximum number of keys to delete [default: INF]
string | null$tagTag to purge a single shard only. This is only supported when server tags are used in configuration.
Returns
bool Success; false if unimplemented

Reimplemented in SqlBagOStuff, ReplicatedBagOStuff, MultiWriteBagOStuff, MediumSpecificBagOStuff, and CachedBagOStuff.

◆ determineKeyPrefixForStats()

BagOStuff::determineKeyPrefixForStats (   $key)
protected
Parameters
string$keyKey generated by an IStoreKeyEncoder instance
Returns
string A stats prefix to describe this class of key (e.g. "objectcache.file")

Definition at line 769 of file BagOStuff.php.

References WRAPPER_COLLECTION_CALLBACK, and WRAPPER_STATS_GROUP.

◆ fieldHasFlags()

◆ genericKeyFromComponents()

BagOStuff::genericKeyFromComponents (   $components)
finalprotected

At a minimum, there must be a keyspace and collection name component.

Parameters
string|int...$components Key components for keyspace, collection name, and IDs
Returns
string Keyspace-prepended list of encoded components as a colon-separated value
Since
1.35

Definition at line 676 of file BagOStuff.php.

Referenced by CachedBagOStuff\makeGlobalKey(), MultiWriteBagOStuff\makeGlobalKey(), ReplicatedBagOStuff\makeGlobalKey(), CachedBagOStuff\makeKey(), MultiWriteBagOStuff\makeKey(), ReplicatedBagOStuff\makeKey(), APCUBagOStuff\makeKeyInternal(), CachedBagOStuff\makeKeyInternal(), EmptyBagOStuff\makeKeyInternal(), HashBagOStuff\makeKeyInternal(), MultiWriteBagOStuff\makeKeyInternal(), RedisBagOStuff\makeKeyInternal(), ReplicatedBagOStuff\makeKeyInternal(), and RESTBagOStuff\makeKeyInternal().

◆ get()

BagOStuff::get (   $key,
  $flags = 0 
)
abstract

Get an item with the given key.

If the key includes a deterministic input hash (e.g. the key can only have the correct value) or complete staleness checks are handled by the caller (e.g. nothing relies on the TTL), then the READ_VERIFIED flag should be set. This lets tiered backends know they can safely upgrade a cached value to higher tiers using standard TTLs.

Parameters
string$key
int$flagsBitfield of BagOStuff::READ_* constants [optional]
Returns
mixed Returns false on failure or if the item does not exist

Reimplemented in ReplicatedBagOStuff, MultiWriteBagOStuff, MediumSpecificBagOStuff, and CachedBagOStuff.

Referenced by McTest\execute(), and CachedBagOStuff\get().

◆ getCurrentTime()

◆ getLastError()

BagOStuff::getLastError ( )
abstract

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

Returns
int ERR_* constant for the "last error" registry
Since
1.23

Reimplemented in ReplicatedBagOStuff, MultiWriteBagOStuff, MediumSpecificBagOStuff, and CachedBagOStuff.

◆ getLogger()

BagOStuff::getLogger ( )
Since
1.35
Returns
LoggerInterface

Definition at line 179 of file BagOStuff.php.

References $logger.

◆ getMulti()

BagOStuff::getMulti ( array  $keys,
  $flags = 0 
)
abstract

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

Parameters
string[]$keysList of keys
int$flagsBitfield; supports READ_LATEST [optional]
Returns
mixed[] Map of (key => value) for existing keys

Reimplemented in ReplicatedBagOStuff, MultiWriteBagOStuff, MediumSpecificBagOStuff, and CachedBagOStuff.

◆ getQoS()

BagOStuff::getQoS (   $flag)
Parameters
int$flagATTR_* class constant
Returns
int QOS_* class constant
Since
1.28

Reimplemented in MediumSpecificBagOStuff.

Definition at line 558 of file BagOStuff.php.

◆ getScopedLock()

BagOStuff::getScopedLock (   $key,
  $timeout = 6,
  $expiry = 30,
  $rclass = '' 
)
final

Get a lightweight exclusive self-unlocking lock.

Note that the same lock cannot be acquired twice.

This is useful for task de-duplication or to avoid obtrusive (though non-corrupting) DB errors like INSERT key conflicts or deadlocks when using LOCK IN SHARE MODE.

Parameters
string$key
int$timeoutLock wait timeout; 0 for non-blocking [optional]
int$expiryLock expiry [optional]; 1 day maximum
string$rclassAllow reentry if set and the current lock used this value
Returns
ScopedCallback|null Returns null on failure
Since
1.26

Definition at line 349 of file BagOStuff.php.

References lock(), and unlock().

◆ getSegmentationSize()

BagOStuff::getSegmentationSize ( )
Returns
int|float The chunk size, in bytes, of segmented objects (INF for no limit)
Since
1.34

Reimplemented in MediumSpecificBagOStuff.

Definition at line 566 of file BagOStuff.php.

◆ getSegmentedValueMaxSize()

BagOStuff::getSegmentedValueMaxSize ( )
Returns
int|float Maximum total segmented object size in bytes (INF for no limit)
Since
1.34

Reimplemented in MediumSpecificBagOStuff.

Definition at line 574 of file BagOStuff.php.

◆ getWithSetCallback()

BagOStuff::getWithSetCallback (   $key,
  $exptime,
  $callback,
  $flags = 0 
)
final

Get an item with the given key, regenerating and setting it if not found.

The callback can take $exptime as argument by reference and modify it. Nothing is stored nor deleted if the callback returns false.

Parameters
string$key
int$exptimeTime-to-live (seconds)
callable$callbackCallback that derives the new value
int$flagsBitfield of BagOStuff::READ_* or BagOStuff::WRITE_* constants [optional]
Returns
mixed The cached value if found or the result of $callback otherwise
Since
1.27

Definition at line 204 of file BagOStuff.php.

◆ incr()

BagOStuff::incr (   $key,
  $value = 1,
  $flags = 0 
)
abstract

Increase stored value of $key by $value while preserving its TTL.

Parameters
string$keyKey to increase
int$valueValue to add to $key (default: 1) [optional]
int$flagsBit field of class WRITE_* constants [optional]
Returns
int|bool New value or false on failure

Reimplemented in WinCacheBagOStuff, RESTBagOStuff, ReplicatedBagOStuff, RedisBagOStuff, MultiWriteBagOStuff, MemcachedPhpBagOStuff, MemcachedPeclBagOStuff, HashBagOStuff, EmptyBagOStuff, CachedBagOStuff, APCUBagOStuff, and SqlBagOStuff.

◆ incrWithInit()

BagOStuff::incrWithInit (   $key,
  $exptime,
  $value = 1,
  $init = null,
  $flags = 0 
)
abstract

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 - $value) and $exptime are invariants for all operations to any given key. The value of $init should be at least that of $value.

Parameters
string$keyKey built via makeKey() or makeGlobalKey()
int$exptimeTime-to-live (in seconds) or a UNIX timestamp expiration
int$valueAmount to increase the key value by [default: 1]
int | null$initValue to initialize the key to if it does not exist [default: $value]
int$flagsBit field of class WRITE_* constants [optional]
Returns
int|bool New value or false on failure
Since
1.24

Reimplemented in ReplicatedBagOStuff, MultiWriteBagOStuff, MediumSpecificBagOStuff, EmptyBagOStuff, CachedBagOStuff, and APCUBagOStuff.

◆ isKeyGlobal()

BagOStuff::isKeyGlobal (   $key)

Check whether a cache key is in the global keyspace.

Parameters
string$key
Returns
bool
Since
1.35

Definition at line 549 of file BagOStuff.php.

◆ lock()

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

Acquire an advisory lock on a key string, exclusive to the caller.

Parameters
string$key
int$timeoutLock wait timeout; 0 for non-blocking [optional]
int$exptimeLock time-to-live in seconds; 1 day maximum [optional]
string$rclassIf this thread already holds the lock, and the lock was acquired using the same value for this parameter, then return true and use reference counting so that only the unlock() call from the outermost lock() caller actually releases the lock (note that only the outermost time-to-live is used) [optional]
Returns
bool Success

Reimplemented in ReplicatedBagOStuff, MultiWriteBagOStuff, MediumSpecificBagOStuff, and CachedBagOStuff.

Referenced by getScopedLock().

◆ makeGlobalKey()

BagOStuff::makeGlobalKey (   $collection,
  $components 
)
abstract

Make a cache key for the default keyspace and given components.

See also
IStoreKeyEncoder::makeGlobalKey()
Parameters
string$collectionKey collection name component
string|int...$components Additional, ordered, key components for entity IDs
Returns
string Colon-separated, keyspace-prepended, ordered list of encoded components
Since
1.27

Implements IStoreKeyEncoder.

Reimplemented in ReplicatedBagOStuff, MultiWriteBagOStuff, MediumSpecificBagOStuff, and CachedBagOStuff.

Referenced by Wikimedia\Rdbms\ChronologyProtector\__construct(), and ExtensionRegistry\makeCacheKey().

◆ makeKey()

BagOStuff::makeKey (   $collection,
  $components 
)
abstract

Make a cache key for the global keyspace and given components.

See also
IStoreKeyEncoder::makeKey()
Parameters
string$collectionKey collection name component
string|int...$components Additional, ordered, key components for entity IDs
Returns
string Colon-separated, keyspace-prepended, ordered list of encoded components
Since
1.27

Implements IStoreKeyEncoder.

Reimplemented in ReplicatedBagOStuff, MultiWriteBagOStuff, MediumSpecificBagOStuff, and CachedBagOStuff.

Referenced by CryptHKDF\__construct(), and UploadBase\getUploadSessionKey().

◆ makeKeyInternal()

BagOStuff::makeKeyInternal (   $keyspace,
  $components 
)
abstract

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.

Access: internal
This method should not be used outside of BagOStuff (since 1.36)
Parameters
string$keyspaceKeyspace component
string[] | int[]$componentsKey components (key collection name first)
Returns
string Keyspace-prepended list of encoded components as a colon-separated value
Since
1.27

Reimplemented in SqlBagOStuff, WinCacheBagOStuff, RESTBagOStuff, ReplicatedBagOStuff, RedisBagOStuff, MultiWriteBagOStuff, MemcachedBagOStuff, HashBagOStuff, EmptyBagOStuff, CachedBagOStuff, and APCUBagOStuff.

◆ merge()

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

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 overriden in the callback. Nothing is stored nor deleted if the callback returns false.

Parameters
string$key
callable$callbackCallback method to be executed
int$exptimeEither an interval in seconds or a unix timestamp for expiry
int$attemptsThe amount of times to attempt a merge in case of failure
int$flagsBitfield of BagOStuff::WRITE_* constants
Returns
bool Success
Exceptions
InvalidArgumentException

Reimplemented in ReplicatedBagOStuff, MultiWriteBagOStuff, MediumSpecificBagOStuff, EmptyBagOStuff, and CachedBagOStuff.

◆ mergeFlagMaps()

BagOStuff::mergeFlagMaps ( array  $bags)
finalprotected

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

Parameters
BagOStuff[]$bags
Returns
int[] Resulting flag map (class ATTR_* constant => class QOS_* constant)

Definition at line 594 of file BagOStuff.php.

Referenced by MultiWriteBagOStuff\__construct(), and ReplicatedBagOStuff\__construct().

◆ proxyCall()

BagOStuff::proxyCall (   $method,
  $arg0Sig,
  $resSig,
array  $genericArgs 
)
protected

Call a method on behalf of wrapper BagOStuff instance that uses "generic" keys.

Parameters
string$methodName of a non-final public method that reads/changes keys
int$arg0SigBagOStuff::ARG0_* constant describing argument 0
int$resSigBagOStuff::RES_* constant describing the return value
array$genericArgsMethod arguments passed to the wrapper instance
Returns
mixed Method result with any resulting cache keys remapped to "generic" keys

Definition at line 726 of file BagOStuff.php.

References convertGenericKey().

◆ registerWrapperInfoForStats()

BagOStuff::registerWrapperInfoForStats ( string  $prefixComponent,
string  $statsGroup,
callable  $collectionCallback 
)

Register info about a caching layer class that uses BagOStuff as a backing store.

Object cache wrappers are classes that implement generic caching/storage functionality, use a BagOStuff instance as the backing store, and implement IStoreKeyEncoder with the same "generic" style key encoding as BagOStuff. Such wrappers transform keys before passing them to BagOStuff methods; a wrapper-specific prefix component will be prepended along with other possible additions. Transformed keys still use the "generic" BagOStuff encoding.

The provided callback takes a transformed key, having the specified prefix component, and extracts the key collection name. For sanity, the callback must be able to handle keys that bear the prefix (by coincidence) but do not originate from the wrapper class.

Calls to this method should be idempotent.

Parameters
string$prefixComponentKey prefix component used by the wrapper
string$statsGroupStats group to use for metrics from this wrapper
callable$collectionCallbackStatic callback that gets the key collection name
Access: internal
For use with BagOStuff and WANObjectCache only
Since
1.36

Definition at line 658 of file BagOStuff.php.

◆ set()

BagOStuff::set (   $key,
  $value,
  $exptime = 0,
  $flags = 0 
)
abstract

Set an item.

Parameters
string$key
mixed$value
int$exptimeEither an interval in seconds or a unix timestamp for expiry
int$flagsBitfield of BagOStuff::WRITE_* constants
Returns
bool Success

Reimplemented in ReplicatedBagOStuff, MultiWriteBagOStuff, MediumSpecificBagOStuff, and CachedBagOStuff.

◆ setDebug()

BagOStuff::setDebug (   $enabled)
Parameters
bool$enabled
Deprecated:
since 1.36, always true

Definition at line 187 of file BagOStuff.php.

References wfDeprecated().

◆ setLogger()

BagOStuff::setLogger ( LoggerInterface  $logger)
Parameters
LoggerInterface$logger
Returns
void

Reimplemented in RESTBagOStuff.

Definition at line 171 of file BagOStuff.php.

References $logger.

Referenced by __construct().

◆ setMockTime()

BagOStuff::setMockTime ( $time)
Access: internal
For testing only
Parameters
float | null&$timeMock UNIX timestamp

Reimplemented in ReplicatedBagOStuff, MultiWriteBagOStuff, and CachedBagOStuff.

Definition at line 804 of file BagOStuff.php.

◆ setMulti()

BagOStuff::setMulti ( array  $valueByKey,
  $exptime = 0,
  $flags = 0 
)
abstract

Batch insertion/replace.

This does not support WRITE_ALLOW_SEGMENTS to avoid excessive read I/O

WRITE_BACKGROUND can be used for bulk insertion where the response is not vital

Parameters
mixed[]$valueByKeyMap of (key => value)
int$exptimeEither an interval in seconds or a unix timestamp for expiry
int$flagsBitfield of BagOStuff::WRITE_* constants (since 1.33)
Returns
bool Success
Since
1.24

Reimplemented in ReplicatedBagOStuff, MultiWriteBagOStuff, MediumSpecificBagOStuff, and CachedBagOStuff.

◆ setNewPreparedValues()

BagOStuff::setNewPreparedValues ( array  $valueByKey)
abstract

Make a "generic" reversible cache key from the given components.

All previously prepared values will be cleared. Each of the new prepared values will be individually cleared as they get used by write operations for that key. This is done to avoid unchecked growth in PHP memory usage.

Example usage:

$valueByKey = [ $key1 => $value1, $key2 => $value2, $key3 => $value3 ];
$cache->setNewPreparedValues( $valueByKey );
$cache->set( $key1, $value1, $cache::TTL_HOUR );
$cache->setMulti( [ $key2 => $value2, $key3 => $value3 ], $cache::TTL_HOUR );

This is only useful if the caller needs an estimate of the serialized object sizes. The caller cannot know the serialization format and even if it did, it could be expensive to serialize complex values twice just to get the size information before writing them to cache. This method solves both problems by making the cache instance do the serialization and having it reuse the result when the cache write happens.

Parameters
array$valueByKeyMap of (cache key => PHP variable value to serialize)
Returns
int[]|null[] Corresponding list of size estimates (null for invalid values)
Since
1.35

Reimplemented in ReplicatedBagOStuff, MultiWriteBagOStuff, MemcachedPeclBagOStuff, MediumSpecificBagOStuff, HashBagOStuff, and CachedBagOStuff.

◆ unlock()

BagOStuff::unlock (   $key)
abstract

Release an advisory lock on a key string.

Parameters
string$key
Returns
bool Success

Reimplemented in ReplicatedBagOStuff, MultiWriteBagOStuff, MediumSpecificBagOStuff, and CachedBagOStuff.

Referenced by getScopedLock().

Member Data Documentation

◆ $asyncHandler

callable null BagOStuff::$asyncHandler
protected

◆ $attrMap

int [] BagOStuff::$attrMap = []
protected

Map of (ATTR_* class constant => QOS_* class constant)

Definition at line 100 of file BagOStuff.php.

◆ $debugMode

bool BagOStuff::$debugMode = true
protected

Whether to send debug log entries to the SPI logger instance.

Deprecated:
since 1.36 – unused

Definition at line 109 of file BagOStuff.php.

◆ $keyspace

◆ $logger

LoggerInterface BagOStuff::$logger
protected

Definition at line 90 of file BagOStuff.php.

Referenced by getLogger(), setLogger(), and RESTBagOStuff\setLogger().

◆ $stats

StatsdDataFactoryInterface BagOStuff::$stats
protected

Definition at line 88 of file BagOStuff.php.

◆ $wallClockOverride

float null BagOStuff::$wallClockOverride
private

Definition at line 112 of file BagOStuff.php.

◆ $wrapperInfoByPrefix

array<string,array> BagOStuff::$wrapperInfoByPrefix = []
protected

Cache key processing callbacks and info for metrics.

Definition at line 97 of file BagOStuff.php.

◆ READ_LATEST

const BagOStuff::READ_LATEST = 1

Bitfield constants for get()/getMulti(); these are only advisory.

Definition at line 115 of file BagOStuff.php.

Referenced by RESTBagOStuff\incr().

◆ READ_VERIFIED

const BagOStuff::READ_VERIFIED = 2

Definition at line 116 of file BagOStuff.php.

Referenced by ParserCache\get(), and ParserCache\getMetadata().

◆ WRAPPER_COLLECTION_CALLBACK

const BagOStuff::WRAPPER_COLLECTION_CALLBACK = 1
private

Key to the callback that extracts collection names from cache wrapper keys.

Definition at line 148 of file BagOStuff.php.

Referenced by determineKeyPrefixForStats().

◆ WRAPPER_STATS_GROUP

const BagOStuff::WRAPPER_STATS_GROUP = 0
private

Key to the metric group to use for the relevant cache wrapper.

Definition at line 146 of file BagOStuff.php.

Referenced by determineKeyPrefixForStats().

◆ WRITE_ALLOW_SEGMENTS

const BagOStuff::WRITE_ALLOW_SEGMENTS = 16

◆ WRITE_BACKGROUND

◆ WRITE_CACHE_ONLY

const BagOStuff::WRITE_CACHE_ONLY = 8

Definition at line 119 of file BagOStuff.php.

Referenced by CachedBagOStuff\get(), and MediaWiki\Session\SessionBackend\save().

◆ WRITE_PRUNE_SEGMENTS

const BagOStuff::WRITE_PRUNE_SEGMENTS = 32

◆ WRITE_SYNC

const BagOStuff::WRITE_SYNC = 4

Bitfield constants for set()/merge(); these are only advisory.

Definition at line 118 of file BagOStuff.php.

Referenced by MediaWiki\Session\SessionBackend\save().


The documentation for this class was generated from the following file:
$cache
$cache
Definition: mcc.php:33