MediaWiki REL1_31
MultiWriteBagOStuff Class Reference

A cache class that replicates all writes to multiple child caches. More...

Inheritance diagram for MultiWriteBagOStuff:
Collaboration diagram for MultiWriteBagOStuff:

Public Member Functions

 __construct ( $params)
 $params include:
 
 add ( $key, $value, $exptime=0)
 
 clearLastError ()
 Clear the "last error" registry.
 
 decr ( $key, $value=1)
 Decrease stored value of $key by $value while preserving its TTL.
 
 delete ( $key)
 Delete an item.
 
 deleteObjectsExpiringBefore ( $date, $progressCallback=false)
 Delete objects expiring before a certain date.
 
 getLastError ()
 Get the "last error" registered; clearLastError() should be called manually.
 
 incr ( $key, $value=1)
 Increase stored value of $key by $value while preserving its TTL.
 
 lock ( $key, $timeout=6, $expiry=6, $rclass='')
 Acquire an advisory lock on a key string.
 
 makeGlobalKey ( $class, $component=null)
 Make a global cache key.
 
 makeKey ( $class, $component=null)
 Make a cache key, scoped to this instance's keyspace.
 
 set ( $key, $value, $exptime=0, $flags=0)
 Set an item.
 
 setDebug ( $debug)
 
 unlock ( $key)
 Release an advisory lock on a key string.
 
- Public Member Functions inherited from BagOStuff
 __construct (array $params=[])
 $params include:
 
 addBusyCallback (callable $workCallback)
 Let a callback be run to avoid wasting time on special blocking calls.
 
 changeTTL ( $key, $expiry=0)
 Reset the TTL on a key if it exists.
 
 get ( $key, $flags=0, $oldFlags=null)
 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)
 
 getScopedLock ( $key, $timeout=6, $expiry=30, $rclass='')
 Get a lightweight exclusive self-unlocking lock.
 
 getWithSetCallback ( $key, $ttl, $callback, $flags=0)
 Get an item with the given key, regenerating and setting it if not found.
 
 incrWithInit ( $key, $ttl, $value=1, $init=1)
 Increase stored value of $key by $value while preserving its TTL.
 
 makeKeyInternal ( $keyspace, $args)
 Construct a cache key.
 
 merge ( $key, callable $callback, $exptime=0, $attempts=10, $flags=0)
 Merge changes into the existing cache value (possibly creating a new one)
 
 modifySimpleRelayEvent (array $event)
 Modify a cache update operation array for EventRelayer::notify()
 
 setLogger (LoggerInterface $logger)
 
 setMockTime (&$time)
 
 setMulti (array $data, $exptime=0)
 Batch insertion.
 

Public Attributes

const ALL = INF
 Idiom for "write to all backends".
 
const UPGRADE_TTL = 3600
 
- Public Attributes inherited from BagOStuff
const ERR_NO_RESPONSE = 1
 
const ERR_NONE = 0
 Possible values for getLastError()
 
const ERR_UNEXPECTED = 3
 
const ERR_UNREACHABLE = 2
 
const READ_LATEST = 1
 Bitfield constants for get()/getMulti()
 
const READ_VERIFIED = 2
 
const WRITE_CACHE_ONLY = 2
 
const WRITE_SYNC = 1
 Bitfield constants for set()/merge()
 
- Public Attributes inherited from IExpiringStore
const ATTR_EMULATION = 1
 
const ATTR_SYNCWRITES = 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

 doGet ( $key, $flags=0)
 
 doWrite ( $count, $asyncWrites, $method)
 Apply a write method to the first $count backing caches.
 
- Protected Member Functions inherited from BagOStuff
 cas ( $casToken, $key, $value, $exptime=0)
 Check and set an item.
 
 convertExpiry ( $exptime)
 Convert an optionally relative time to an absolute time.
 
 convertToRelative ( $exptime)
 Convert an optionally absolute expiry time to a relative time.
 
 debug ( $text)
 
 getCurrentTime ()
 
 getWithToken ( $key, &$casToken, $flags=0)
 
 isInteger ( $value)
 Check if a value is an integer.
 
 mergeFlagMaps (array $bags)
 Merge the flag maps of one or more BagOStuff objects into a "lowest common denominator" map.
 
 mergeViaCas ( $key, $callback, $exptime=0, $attempts=10)
 
 mergeViaLock ( $key, $callback, $exptime=0, $attempts=10, $flags=0)
 
 setLastError ( $err)
 Set the "last error" registry.
 

Protected Attributes

bool $asyncWrites = false
 Use async secondary writes.
 
BagOStuff[] $caches
 
- Protected Attributes inherited from BagOStuff
callback null $asyncHandler
 
int[] $attrMap = []
 Map of (ATTR_* class constant => QOS_* class constant)
 
callable[] $busyCallbacks = []
 
string $keyspace = 'local'
 
int $lastError = self::ERR_NONE
 ERR_* class constant.
 
array[] $locks = []
 Lock tracking.
 
LoggerInterface $logger
 
int $syncTimeout
 Seconds.
 

Detailed Description

A cache class that replicates all writes to multiple child caches.

Reads are implemented by reading from the caches in the order they are given in the configuration until a cache gives a positive result.

Definition at line 32 of file MultiWriteBagOStuff.php.

Constructor & Destructor Documentation

◆ __construct()

MultiWriteBagOStuff::__construct ( $params)

$params include:

  • caches: A numbered array of either ObjectFactory::getObjectFromSpec arrays yeilding BagOStuff objects or direct BagOStuff objects. If using the former, the 'args' field must be set. The first cache is the primary one, being the first to be read in the fallback chain. Writes happen to all stores in the order they are defined. However, lock()/unlock() calls only use the primary store.
  • replication: Either 'sync' or 'async'. This controls whether writes to secondary stores are deferred when possible. Async writes require setting 'asyncHandler'. HHVM register_postsend_function() function. Async writes can increase the chance of some race conditions or cause keys to expire seconds later than expected. It is safe to use for modules when cached values: are immutable, invalidation uses logical TTLs, invalidation uses etag/timestamp validation against the DB, or merge() is used to handle races.
    Parameters
    array$params
    Exceptions
    InvalidArgumentException

Definition at line 63 of file MultiWriteBagOStuff.php.

References $params, and BagOStuff\mergeFlagMaps().

Member Function Documentation

◆ add()

MultiWriteBagOStuff::add ( $key,
$value,
$exptime = 0 )
Parameters
string$key
mixed$value
int$exptime
Returns
bool Success

Reimplemented from BagOStuff.

Definition at line 142 of file MultiWriteBagOStuff.php.

References $value, and doWrite().

◆ clearLastError()

MultiWriteBagOStuff::clearLastError ( )

Clear the "last error" registry.

Since
1.23

Reimplemented from BagOStuff.

Definition at line 168 of file MultiWriteBagOStuff.php.

◆ decr()

MultiWriteBagOStuff::decr ( $key,
$value = 1 )

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

Parameters
string$key
int$value
Returns
int|bool New value or false on failure

Reimplemented from BagOStuff.

Definition at line 150 of file MultiWriteBagOStuff.php.

References $value, and doWrite().

◆ delete()

MultiWriteBagOStuff::delete ( $key)

Delete an item.

Parameters
string$key
Returns
bool True if the item was deleted or not found, false on failure

Reimplemented from BagOStuff.

Definition at line 138 of file MultiWriteBagOStuff.php.

References doWrite().

◆ deleteObjectsExpiringBefore()

MultiWriteBagOStuff::deleteObjectsExpiringBefore ( $date,
$progressCallback = false )

Delete objects expiring before a certain date.

Succeed if any of the child caches succeed.

Parameters
string$date
bool | callable$progressCallback
Returns
bool

Reimplemented from BagOStuff.

Definition at line 226 of file MultiWriteBagOStuff.php.

References $cache, and $ret.

◆ doGet()

MultiWriteBagOStuff::doGet ( $key,
$flags = 0 )
protected
Parameters
string$key
int$flagsBitfield of BagOStuff::READ_* constants [optional]
Returns
mixed Returns false on failure and if the item does not exist

Reimplemented from BagOStuff.

Definition at line 102 of file MultiWriteBagOStuff.php.

References $cache, $value, and doWrite().

◆ doWrite()

MultiWriteBagOStuff::doWrite ( $count,
$asyncWrites,
$method )
protected

Apply a write method to the first $count backing caches.

Parameters
int$count
bool$asyncWrites
string$method
mixed$args,...
Returns
bool

Definition at line 181 of file MultiWriteBagOStuff.php.

References $args, $asyncWrites, $cache, BagOStuff\$logger, $ret, serialize(), and unserialize().

Referenced by add(), decr(), delete(), doGet(), incr(), and set().

◆ getLastError()

MultiWriteBagOStuff::getLastError ( )

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

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

Reimplemented from BagOStuff.

Definition at line 164 of file MultiWriteBagOStuff.php.

◆ incr()

MultiWriteBagOStuff::incr ( $key,
$value = 1 )

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

Parameters
string$keyKey to increase
int$valueValue to add to $key (Default 1)
Returns
int|bool New value or false on failure

Reimplemented from BagOStuff.

Definition at line 146 of file MultiWriteBagOStuff.php.

References $value, and doWrite().

◆ lock()

MultiWriteBagOStuff::lock ( $key,
$timeout = 6,
$expiry = 6,
$rclass = '' )

Acquire an advisory lock on a key string.

Note that if reentry is enabled, duplicate calls ignore $expiry

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
bool Success

Reimplemented from BagOStuff.

Definition at line 154 of file MultiWriteBagOStuff.php.

◆ makeGlobalKey()

MultiWriteBagOStuff::makeGlobalKey ( $class,
$component = null )

Make a global cache key.

Since
1.27
Parameters
string$classKey class
string$component[optional] Key component (starting with a key collection name)
Returns
string Colon-delimited list of $keyspace followed by escaped components of $args

Reimplemented from BagOStuff.

Definition at line 241 of file MultiWriteBagOStuff.php.

Referenced by MultiWriteBagOStuffTest\testMakeGlobalKey().

◆ makeKey()

MultiWriteBagOStuff::makeKey ( $class,
$component = null )

Make a cache key, scoped to this instance's keyspace.

Since
1.27
Parameters
string$classKey class
string$component[optional] Key component (starting with a key collection name)
Returns
string Colon-delimited list of $keyspace followed by escaped components of $args

Reimplemented from BagOStuff.

Definition at line 237 of file MultiWriteBagOStuff.php.

Referenced by MultiWriteBagOStuffTest\testMakeKey().

◆ set()

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

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 from BagOStuff.

Definition at line 130 of file MultiWriteBagOStuff.php.

References $asyncWrites, $value, doWrite(), false, and BagOStuff\WRITE_SYNC.

◆ setDebug()

MultiWriteBagOStuff::setDebug ( $bool)
Parameters
bool$bool

Reimplemented from BagOStuff.

Definition at line 96 of file MultiWriteBagOStuff.php.

References $cache, and $debug.

◆ unlock()

MultiWriteBagOStuff::unlock ( $key)

Release an advisory lock on a key string.

Parameters
string$key
Returns
bool Success

Reimplemented from BagOStuff.

Definition at line 159 of file MultiWriteBagOStuff.php.

Member Data Documentation

◆ $asyncWrites

bool MultiWriteBagOStuff::$asyncWrites = false
protected

Use async secondary writes.

Definition at line 36 of file MultiWriteBagOStuff.php.

Referenced by doWrite(), and set().

◆ $caches

BagOStuff [] MultiWriteBagOStuff::$caches
protected

Definition at line 34 of file MultiWriteBagOStuff.php.

◆ ALL

const MultiWriteBagOStuff::ALL = INF

Idiom for "write to all backends".

Definition at line 39 of file MultiWriteBagOStuff.php.

◆ UPGRADE_TTL

const MultiWriteBagOStuff::UPGRADE_TTL = 3600

Definition at line 41 of file MultiWriteBagOStuff.php.


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