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Zend Framework
3.0
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Re-usable, serializable priority queue implementation. More...
Public Member Functions | |
| insert ($data, $priority=1) | |
| Insert an item into the queue. | |
| remove ($datum) | |
| Remove an item from the queue. | |
| isEmpty () | |
| Is the queue empty? | |
| count () | |
| How many items are in the queue? | |
| top () | |
| Peek at the top node in the queue, based on priority. | |
| extract () | |
| Extract a node from the inner queue and sift up. | |
| getIterator () | |
| Retrieve the inner iterator. | |
| serialize () | |
| Serialize the data structure. | |
| unserialize ($data) | |
| Unserialize a string into a PriorityQueue object. | |
| toArray ($flag=self::EXTR_DATA) | |
| Serialize to an array. | |
| setInternalQueueClass ($class) | |
| Specify the internal queue class. | |
| contains ($datum) | |
| Does the queue contain the given datum? | |
| hasPriority ($priority) | |
| Does the queue have an item with the given priority? | |
| __clone () | |
| Add support for deep cloning. | |
Public Attributes | |
| const | EXTR_DATA = 0x00000001 |
| const | EXTR_PRIORITY = 0x00000002 |
| const | EXTR_BOTH = 0x00000003 |
Protected Member Functions | |
| getQueue () | |
| Get the inner priority queue instance. | |
Protected Attributes | |
| $queueClass = 'Zend\Stdlib\SplPriorityQueue' | |
| $items = [] | |
| $queue | |
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.
| __clone | ( | ) |
Add support for deep cloning.
| contains | ( | $datum | ) |
Does the queue contain the given datum?
| mixed | $datum |
| count | ( | ) |
How many items are in the queue?
| extract | ( | ) |
Extract a node from the inner queue and sift up.
| getIterator | ( | ) |
Retrieve 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.
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protected |
| hasPriority | ( | $priority | ) |
Does the queue have an item with the given priority?
| int | $priority |
| insert | ( | $data, | |
$priority = 1 |
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Insert an item into the queue.
Priority defaults to 1 (low priority) if none provided.
| mixed | $data | |
| int | $priority |
| isEmpty | ( | ) |
Is the queue empty?
| remove | ( | $datum | ) |
Remove 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.
| mixed | $datum |
| serialize | ( | ) |
Serialize the data structure.
| setInternalQueueClass | ( | $class | ) |
Specify the internal queue class.
Please see getIterator() for details on the necessity of an internal queue class. The class provided should extend SplPriorityQueue.
| string | $class |
| toArray | ( | $flag = self::EXTR_DATA | ) |
Serialize 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.
| int | $flag |
| top | ( | ) |
Peek at the top node in the queue, based on priority.
| unserialize | ( | $data | ) |
Unserialize a string into a PriorityQueue object.
Serialization format is compatible with Zend
| string | $data |
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protected |
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protected |
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protected |
| const EXTR_BOTH = 0x00000003 |
| const EXTR_DATA = 0x00000001 |
| const EXTR_PRIORITY = 0x00000002 |
1.8.3