Stdlib/PriorityQueue.php
inherited
Classes
Zend Framework
LICENSE
This source file is subject to the new BSD license that is bundled with this package in the file LICENSE.txt. It is also available through the world-wide-web at this URL: http://framework.zend.com/license/new-bsd If you did not receive a copy of the license and are unable to obtain it through the world-wide-web, please send an email to [email protected] so we can send you a copy immediately.
- Category
- Zend
- Copyright
- Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
- License
- New BSD License
- Package
- Zend_Stdlib
\Zend_Stdlib_PriorityQueue
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.
- Implements
- Category
- Zend
- Copyright
- Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
- License
- New BSD License
Constants
Properties
array $items = array()Actual items aggregated in the priority queue.
Each item is an array with keys "data" and "priority".
array()Details- Type
- array
string $queueClass = 'Zend_Stdlib_SplPriorityQueue'Inner queue class to use for iteration
'Zend_Stdlib_SplPriorityQueue'Details- Type
- string
Methods
contains(mixed $datum) : boolDoes the queue contain the given datum?
| Name | Type | Description |
|---|---|---|
| $datum | mixed |
| Type | Description |
|---|---|
| bool |
count() : intHow many items are in the queue?
| Type | Description |
|---|---|
| int |
extract() : mixedExtract a node from the inner queue and sift up
| Type | Description |
|---|---|
| mixed |
getIterator() : \SplPriorityQueueRetrieve the inner iterator
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.
| Type | Description |
|---|---|
| \SplPriorityQueue |
getQueue() : \Zend_Stdlib_SplPriorityQueueGet the inner priority queue instance
| Type | Description |
|---|---|
| \Zend_Stdlib_SplPriorityQueue |
hasPriority(int $priority) : boolDoes the queue have an item with the given priority?
| Name | Type | Description |
|---|---|---|
| $priority | int |
| Type | Description |
|---|---|
| bool |
insert(mixed $data, int $priority = 1) : \Zend_Stdlib_PriorityQueueInsert an item into the queue
Priority defaults to 1 (low priority) if none provided.
| Name | Type | Description |
|---|---|---|
| $data | mixed | |
| $priority | int |
| Type | Description |
|---|---|
| \Zend_Stdlib_PriorityQueue |
isEmpty() : boolIs the queue empty?
| Type | Description |
|---|---|
| bool |
remove(mixed $datum) : booleanRemove an item from the queue
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.
| Name | Type | Description |
|---|---|---|
| $datum | mixed |
| Type | Description |
|---|---|
| boolean | False if the item was not found, true otherwise. |
returnData(array $item) : mixedReturn data from an internal item
Used as a lambda in toArray().
| Name | Type | Description |
|---|---|---|
| $item | array |
| Type | Description |
|---|---|
| mixed |
returnPriority(array $item) : mixedReturn priority from an internal item
Used as a lambda in toArray().
| Name | Type | Description |
|---|---|---|
| $item | array |
| Type | Description |
|---|---|
| mixed |
serialize() : stringSerialize the data structure
| Type | Description |
|---|---|
| string |
setInternalQueueClass(string $class) : \Zend_Stdlib_PriorityQueueSpecify the internal queue class
Please see getIterator() for details on the necessity of an internal queue class. The class provided should extend SplPriorityQueue.
| Name | Type | Description |
|---|---|---|
| $class | string |
| Type | Description |
|---|---|
| \Zend_Stdlib_PriorityQueue |
toArray(int $flag = self::EXTR_DATA) : arraySerialize to an 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.
| Name | Type | Description |
|---|---|---|
| $flag | int |
| Type | Description |
|---|---|
| array |
top() : mixedPeek at the top node in the queue, based on priority.
| Type | Description |
|---|---|
| mixed |
unserialize(string $data) : voidUnserialize a string into a Zend_Stdlib_PriorityQueue object
Serialization format is compatible with Zend_Stdlib_SplPriorityQueue
| Name | Type | Description |
|---|---|---|
| $data | string |