Wikibase\Lib\Store\ChunkCache Class Reference

Interface for DAO objects providing chunked access. More...

Inheritance diagram for Wikibase\Lib\Store\ChunkCache:

Collaboration diagram for Wikibase\Lib\Store\ChunkCache:

Public Member Functions
	__construct (ChunkAccess $source, $chunkSize, $maxSize)
	loadChunk ( $start, $size)
	Returns a chunk as a list of whatever object is used for data records by the implementing class.
	getRecordId ( $rec)
	Returns the sequential ID of the given data record.

Private Member Functions
	findEntryPosition ( $key)
	Finds the position for the given key in the internal entry array.
	insertChunk ( $start, $size, $before)
	prune ()
	Removes least recently used chunks until the total size is smaller than the max size specified in the constructor.

Private Attributes
	$source
	$entries = []
	$size = 0
	$maxSize
	$chunkSize
	$hitCount = 0
	$missCount = 0
	$modCount = 0

Detailed Description

Interface for DAO objects providing chunked access.

Copyright

GPL-2.0-or-later

Author

Daniel Kinzler

Constructor & Destructor Documentation

__construct()

Wikibase\Lib\Store\ChunkCache::__construct	(	ChunkAccess	$source,
			$chunkSize,
			$maxSize
	)

Parameters

ChunkAccess	$source	The source to load from
int	$chunkSize	The size of the chunk to load, if we have a choice
int	$maxSize	The maximum size this cache can grow to

Exceptions

MWException

Member Function Documentation

findEntryPosition()

Wikibase\Lib\Store\ChunkCache::findEntryPosition (   $key )

private

Finds the position for the given key in the internal entry array.

This is implemented using iterative binary search.

Parameters

int

$key

Returns

int the position if found, or the negative insert position minus one, if not.

getRecordId()

Wikibase\Lib\Store\ChunkCache::getRecordId

(

$rec

)

Returns the sequential ID of the given data record.

Parameters

mixed

$rec

Returns

int

Implements Wikibase\Lib\Store\ChunkAccess.

insertChunk()

Wikibase\Lib\Store\ChunkCache::insertChunk (   $start,   $size,   $before  )

private

Parameters

int	$start	the ID to start loading at
int	$size	the maximum size of the chunk to load
int	$before	insert into the internal entry list before this position.

Exceptions

MWException

Returns

array|bool the cache entry created by inserting the new chunk, or false if there is no more data to load from the source at the given position. The cache entry is an associative array containing the following keys:

• start: the key the chunk starts at
• data: a list of data records
• next: the id the following chunk starts at (or after)
• touched: (logical) timestamp of the entry's creation (taken from $this->modCount)

loadChunk()

Wikibase\Lib\Store\ChunkCache::loadChunk	(		$start,
			$size
	)

Returns a chunk as a list of whatever object is used for data records by the implementing class.

Parameters

int	$start	The first ID in the chunk
int	$size	The desired size of the chunk

Returns

array the desired chunk of rows/objects

Implements Wikibase\Lib\Store\ChunkAccess.

prune()

Wikibase\Lib\Store\ChunkCache::prune ( )

private

Removes least recently used chunks until the total size is smaller than the max size specified in the constructor.

Member Data Documentation

$chunkSize

Wikibase\Lib\Store\ChunkCache::$chunkSize

private

$entries

Wikibase\Lib\Store\ChunkCache::$entries = []

private

$hitCount

Wikibase\Lib\Store\ChunkCache::$hitCount = 0

private

$maxSize

Wikibase\Lib\Store\ChunkCache::$maxSize

private

$missCount

Wikibase\Lib\Store\ChunkCache::$missCount = 0

private

$modCount

Wikibase\Lib\Store\ChunkCache::$modCount = 0

private

$size

Wikibase\Lib\Store\ChunkCache::$size = 0

private

$source

Wikibase\Lib\Store\ChunkCache::$source

private

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

• lib/includes/Store/ChunkCache.php