Merge branch 'feature/5702' into develop

Close zendframework/zendframework#5702

src/PriorityList.php

@@ -0,0 +1,263 @@
+<?php
+/**
+ * Zend Framework (http://framework.zend.com/)
+ *
+ * @link      http://github.com/zendframework/zf2 for the canonical source repository
+ * @copyright Copyright (c) 2005-2014 Zend Technologies USA Inc. (http://www.zend.com)
+ * @license   http://framework.zend.com/license/new-bsd New BSD License
+ */
+
+namespace Zend\Stdlib;
+
+use Countable;
+use Iterator;
+
+/**
+ * Priority list
+ */
+class PriorityList implements Iterator, Countable
+{
+    const EXTR_DATA     = 0x00000001;
+    const EXTR_PRIORITY = 0x00000002;
+    const EXTR_BOTH     = 0x00000003;
+    /**
+     * Internal list of all items.
+     *
+     * @var array
+     */
+    protected $items = array();
+
+    /**
+     * Serial assigned to items to preserve LIFO.
+     *
+     * @var int
+     */
+    protected $serial = 0;
+
+    /**
+     * Serial order mode
+     * @var integer
+     */
+    protected $isLIFO = 1;
+
+    /**
+     * Internal counter to avoid usage of count().
+     *
+     * @var int
+     */
+    protected $count = 0;
+
+    /**
+     * Whether the list was already sorted.
+     *
+     * @var bool
+     */
+    protected $sorted = false;
+
+    /**
+     * Insert a new item.
+     *
+     * @param  string  $name
+     * @param  mixed $value
+     * @param  int $priority
+     * @return void
+     */
+    public function insert($name, $value, $priority = 0)
+    {
+        $this->sorted = false;
+        $this->count++;
+
+        $this->items[$name] = array(
+            'data'     => $value,
+            'priority' => (int) $priority,
+            'serial'   => $this->serial++,
+        );
+    }
+
+    public function setPriority($name, $priority)
+    {
+        if (!isset($this->items[$name])) {
+            throw new \Exception("item $name not found");
+        }
+        $this->items[$name]['priority'] = (int) $priority;
+        $this->sorted = false;
+        return $this;
+    }
+
+    /**
+     * Remove a item.
+     *
+     * @param  string $name
+     * @return void
+     */
+    public function remove($name)
+    {
+        if (!isset($this->items[$name])) {
+            return;
+        }
+
+        $this->count--;
+        unset($this->items[$name]);
+    }
+
+    /**
+     * Remove all items.
+     *
+     * @return void
+     */
+    public function clear()
+    {
+        $this->items = array();
+        $this->serial = 0;
+        $this->count  = 0;
+        $this->sorted = false;
+    }
+
+    /**
+     * Get a item.
+     *
+     * @param  string $name
+     * @return mixed
+     */
+    public function get($name)
+    {
+        if (!isset($this->items[$name])) {
+            return null;
+        }
+
+        return $this->items[$name]['data'];
+    }
+
+    /**
+     * Sort all items.
+     *
+     * @return void
+     */
+    protected function sort()
+    {
+        if (!$this->sorted) {
+            uasort($this->items, array($this, 'compare'));
+            $this->sorted = true;
+        }
+    }
+
+    /**
+     * Compare the priority of two items.
+     *
+     * @param  array $item1,
+     * @param  array $item2
+     * @return int
+     */
+    protected function compare(array $item1, array $item2)
+    {
+        return ($item1['priority'] === $item2['priority'])
+            ? ($item1['serial']   > $item2['serial']   ? -1 : 1) * $this->isLIFO
+            : ($item1['priority'] > $item2['priority'] ? -1 : 1);
+    }
+
+    /**
+     * Get/Set serial order mode
+     *
+     * @param bool $flag
+     * @return bool
+     */
+    public function isLIFO($flag = null)
+    {
+        if ($flag !== null) {
+            if (($flag = ($flag === true ? 1 : -1)) !== $this->isLIFO) {
+                $this->isLIFO = $flag;
+                $this->sorted = false;
+            }
+        }
+        return $this->isLIFO === 1;
+    }
+
+    /**
+     * rewind(): defined by Iterator interface.
+     *
+     * @see    Iterator::rewind()
+     * @return void
+     */
+    public function rewind()
+    {
+        $this->sort();
+        reset($this->items);
+    }
+
+    /**
+     * current(): defined by Iterator interface.
+     *
+     * @see    Iterator::current()
+     * @return mixed
+     */
+    public function current()
+    {
+        $node = current($this->items);
+        return ($node !== false ? $node['data'] : false);
+    }
+
+    /**
+     * key(): defined by Iterator interface.
+     *
+     * @see    Iterator::key()
+     * @return string
+     */
+    public function key()
+    {
+        return key($this->items);
+    }
+
+    /**
+     * next(): defined by Iterator interface.
+     *
+     * @see    Iterator::next()
+     * @return mixed
+     */
+    public function next()
+    {
+        $node = next($this->items);
+        return ($node !== false ? $node['data'] : false);
+    }
+
+    /**
+     * valid(): defined by Iterator interface.
+     *
+     * @see    Iterator::valid()
+     * @return bool
+     */
+    public function valid()
+    {
+        return ($this->current() !== false);
+    }
+
+    /**
+     * count(): defined by Countable interface.
+     *
+     * @see    Countable::count()
+     * @return int
+     */
+    public function count()
+    {
+        return $this->count;
+    }
+
+    /**
+     * Return list as array
+     *
+     * @param type $raw
+     * @return array
+     */
+    public function toArray($flag = self::EXTR_DATA)
+    {
+        $this->sort();
+        if ($flag == self::EXTR_BOTH) {
+            return $this->items;
+        }
+        return array_map(
+            ($flag == self::EXTR_PRIORITY)
+                ? function ($item) { return $item['priority']; }
+                : function ($item) { return $item['data']; },
+            $this->items
+        );
+    }
+}