Re-usable, serializable priority queue implementation
SplPriorityQueue acts as a heap; on iteration, each item is removed from the queue. If you wish to re-use such a queue, you need to clone it first. This makes for some interesting issues if you wish to delete items from the queue, or, as already stated, iterate over it multiple times.
This class aggregates items for the queue itself, but also composes an "inner" iterator in the form of an SplPriorityQueue object for performing the actual iteration.
category | Zend |
---|---|
package | Zend_Stdlib |
copyright | Copyright (c) 2005-2015 Zend Technologies USA Inc. (http://www.zend.com) |
license | New BSD License |
contains(mixed $datum) : boolean
mixed
boolean
count() : integer
integer
extract() : mixed
mixed
getIterator() : \SplPriorityQueue
SplPriorityQueue acts as a heap, which typically implies that as items are iterated, they are also removed. This does not work for situations where the queue may be iterated multiple times. As such, this class aggregates the values, and also injects an SplPriorityQueue. This method retrieves the inner queue object, and clones it for purposes of iteration.
\SplPriorityQueue
hasPriority(integer $priority) : boolean
integer
boolean
insert(mixed $data, integer $priority = 1
) : \Zend_Stdlib_PriorityQueue
Priority defaults to 1 (low priority) if none provided.
mixed
integer
\Zend_Stdlib_PriorityQueue
isEmpty() : boolean
boolean
remove(mixed $datum) : boolean
This is different than \extract(); its purpose is to dequeue an item.
This operation is potentially expensive, as it requires re-initialization and re-population of the inner queue.
Note: this removes the first item matching the provided item found. If the same item has been added multiple times, it will not remove other instances.
mixed
boolean
False if the item was not found, true otherwise.returnData(array $item) : mixed
Used as a lambda in toArray().
array
mixed
returnPriority(array $item) : mixed
Used as a lambda in toArray().
array
mixed
serialize() : string
string
setInternalQueueClass(string $class) : \Zend_Stdlib_PriorityQueue
Please see \getIterator() for details on the necessity of an internal queue class. The class provided should extend SplPriorityQueue.
string
\Zend_Stdlib_PriorityQueue
toArray(integer $flag = self::EXTR_DATA
) : array
By default, returns only the item data, and in the order registered (not sorted). You may provide one of the EXTR_* flags as an argument, allowing the ability to return priorities or both data and priority.
integer
array
top() : mixed
mixed
unserialize(string $data) : void
getQueue() : \Zend_Stdlib_SplPriorityQueue
\Zend_Stdlib_SplPriorityQueue
$items : array
array()
$queue : \SplPriorityQueue
$queueClass : string
'Zend_Stdlib_SplPriorityQueue'
EXTR_BOTH = 3
EXTR_DATA = 1
EXTR_PRIORITY = 2