interface/modules/zend_modules/library/Zend/Stdlib/SplPriorityQueue.php

   1 <?php
   2 /**
   3  * Zend Framework (http://framework.zend.com/)
   4  *
   5  * @link      http://github.com/zendframework/zf2 for the canonical source repository
   6  * @copyright Copyright (c) 2005-2013 Zend Technologies USA Inc. (http://www.zend.com)
   7  * @license   http://framework.zend.com/license/new-bsd New BSD License
   8  */
   9
  10 namespace Zend\Stdlib;
  11
  12 use Serializable;
  13
  14 /**
  15  * Serializable version of SplPriorityQueue
  16  *
  17  * Also, provides predictable heap order for datums added with the same priority
  18  * (i.e., they will be emitted in the same order they are enqueued).
  19  */
  20 class SplPriorityQueue extends \SplPriorityQueue implements Serializable
  21 {
  22     /**
  23      * @var int Seed used to ensure queue order for items of the same priority
  24      */
  25     protected $serial = PHP_INT_MAX;
  26
  27     /**
  28      * Insert a value with a given priority
  29      *
  30      * Utilizes {@var $serial} to ensure that values of equal priority are
  31      * emitted in the same order in which they are inserted.
  32      *
  33      * @param  mixed $datum
  34      * @param  mixed $priority
  35      * @return void
  36      */
  37     public function insert($datum, $priority)
  38     {
  39         if (!is_array($priority)) {
  40             $priority = array($priority, $this->serial--);
  41         }
  42         parent::insert($datum, $priority);
  43     }
  44
  45
  46     /**
  47      * Serialize to an array
  48      *
  49      * Array will be priority => data pairs
  50      *
  51      * @return array
  52      */
  53     public function toArray()
  54     {
  55         $array = array();
  56         foreach (clone $this as $item) {
  57             $array[] = $item;
  58         }
  59         return $array;
  60     }
  61
  62
  63     /**
  64      * Serialize
  65      *
  66      * @return string
  67      */
  68     public function serialize()
  69     {
  70         $clone = clone $this;
  71         $clone->setExtractFlags(self::EXTR_BOTH);
  72
  73         $data = array();
  74         foreach ($clone as $item) {
  75             $data[] = $item;
  76         }
  77
  78         return serialize($data);
  79     }
  80
  81     /**
  82      * Deserialize
  83      *
  84      * @param  string $data
  85      * @return void
  86      */
  87     public function unserialize($data)
  88     {
  89         foreach (unserialize($data) as $item) {
  90             $this->insert($item['data'], $item['priority']);
  91         }
  92     }
  93 }