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   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) 2005-2015 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 Countable;
  13  use Iterator;
  14  
  15  class PriorityList implements Iterator, Countable
  16  {
  17      const EXTR_DATA     = 0x00000001;
  18      const EXTR_PRIORITY = 0x00000002;
  19      const EXTR_BOTH     = 0x00000003;
  20      /**
  21       * Internal list of all items.
  22       *
  23       * @var array[]
  24       */
  25      protected $items = array();
  26  
  27      /**
  28       * Serial assigned to items to preserve LIFO.
  29       *
  30       * @var int
  31       */
  32      protected $serial = 0;
  33  
  34      /**
  35       * Serial order mode
  36       * @var integer
  37       */
  38      protected $isLIFO = 1;
  39  
  40      /**
  41       * Internal counter to avoid usage of count().
  42       *
  43       * @var int
  44       */
  45      protected $count = 0;
  46  
  47      /**
  48       * Whether the list was already sorted.
  49       *
  50       * @var bool
  51       */
  52      protected $sorted = false;
  53  
  54      /**
  55       * Insert a new item.
  56       *
  57       * @param  string  $name
  58       * @param  mixed   $value
  59       * @param  int     $priority
  60       *
  61       * @return void
  62       */
  63      public function insert($name, $value, $priority = 0)
  64      {
  65          $this->sorted = false;
  66          $this->count++;
  67  
  68          $this->items[$name] = array(
  69              'data'     => $value,
  70              'priority' => (int) $priority,
  71              'serial'   => $this->serial++,
  72          );
  73      }
  74  
  75      /**
  76       * @param string $name
  77       * @param int    $priority
  78       *
  79       * @return $this
  80       *
  81       * @throws \Exception
  82       */
  83      public function setPriority($name, $priority)
  84      {
  85          if (!isset($this->items[$name])) {
  86              throw new \Exception("item $name not found");
  87          }
  88  
  89          $this->items[$name]['priority'] = (int) $priority;
  90          $this->sorted                   = false;
  91  
  92          return $this;
  93      }
  94  
  95      /**
  96       * Remove a item.
  97       *
  98       * @param  string $name
  99       * @return void
 100       */
 101      public function remove($name)
 102      {
 103          if (isset($this->items[$name])) {
 104              $this->count--;
 105          }
 106  
 107          unset($this->items[$name]);
 108      }
 109  
 110      /**
 111       * Remove all items.
 112       *
 113       * @return void
 114       */
 115      public function clear()
 116      {
 117          $this->items  = array();
 118          $this->serial = 0;
 119          $this->count  = 0;
 120          $this->sorted = false;
 121      }
 122  
 123      /**
 124       * Get a item.
 125       *
 126       * @param  string $name
 127       * @return mixed
 128       */
 129      public function get($name)
 130      {
 131          if (!isset($this->items[$name])) {
 132              return;
 133          }
 134  
 135          return $this->items[$name]['data'];
 136      }
 137  
 138      /**
 139       * Sort all items.
 140       *
 141       * @return void
 142       */
 143      protected function sort()
 144      {
 145          if (!$this->sorted) {
 146              uasort($this->items, array($this, 'compare'));
 147              $this->sorted = true;
 148          }
 149      }
 150  
 151      /**
 152       * Compare the priority of two items.
 153       *
 154       * @param  array $item1,
 155       * @param  array $item2
 156       * @return int
 157       */
 158      protected function compare(array $item1, array $item2)
 159      {
 160          return ($item1['priority'] === $item2['priority'])
 161              ? ($item1['serial']   > $item2['serial']   ? -1 : 1) * $this->isLIFO
 162              : ($item1['priority'] > $item2['priority'] ? -1 : 1);
 163      }
 164  
 165      /**
 166       * Get/Set serial order mode
 167       *
 168       * @param bool|null $flag
 169       *
 170       * @return bool
 171       */
 172      public function isLIFO($flag = null)
 173      {
 174          if ($flag !== null) {
 175              $isLifo = $flag === true ? 1 : -1;
 176  
 177              if ($isLifo !== $this->isLIFO) {
 178                  $this->isLIFO = $isLifo;
 179                  $this->sorted = false;
 180              }
 181          }
 182  
 183          return 1 === $this->isLIFO;
 184      }
 185  
 186      /**
 187       * {@inheritDoc}
 188       */
 189      public function rewind()
 190      {
 191          $this->sort();
 192          reset($this->items);
 193      }
 194  
 195      /**
 196       * {@inheritDoc}
 197       */
 198      public function current()
 199      {
 200          $this->sorted || $this->sort();
 201          $node = current($this->items);
 202  
 203          return $node ? $node['data'] : false;
 204      }
 205  
 206      /**
 207       * {@inheritDoc}
 208       */
 209      public function key()
 210      {
 211          $this->sorted || $this->sort();
 212          return key($this->items);
 213      }
 214  
 215      /**
 216       * {@inheritDoc}
 217       */
 218      public function next()
 219      {
 220          $node = next($this->items);
 221  
 222          return $node ? $node['data'] : false;
 223      }
 224  
 225      /**
 226       * {@inheritDoc}
 227       */
 228      public function valid()
 229      {
 230          return current($this->items) !== false;
 231      }
 232  
 233      /**
 234       * @return self
 235       */
 236      public function getIterator()
 237      {
 238          return clone $this;
 239      }
 240  
 241      /**
 242       * {@inheritDoc}
 243       */
 244      public function count()
 245      {
 246          return $this->count;
 247      }
 248  
 249      /**
 250       * Return list as array
 251       *
 252       * @param int $flag
 253       *
 254       * @return array
 255       */
 256      public function toArray($flag = self::EXTR_DATA)
 257      {
 258          $this->sort();
 259  
 260          if ($flag == self::EXTR_BOTH) {
 261              return $this->items;
 262          }
 263  
 264          return array_map(
 265              function ($item) use ($flag) {
 266                  return ($flag == PriorityList::EXTR_PRIORITY) ? $item['priority'] : $item['data'];
 267              },
 268              $this->items
 269          );
 270      }
 271  }