Added serializable SPL data structures

- Extended SplQueue, SplStack, and SplPriorityQueue to add the ability to
  serialize each, as well as provide toArray() methods.

src/SplPriorityQueue.php

@@ -0,0 +1,77 @@
+<?php
+namespace Zend\Stdlib;
+
+class SplPriorityQueue extends \SplPriorityQueue
+{
+    /**
+     * @var array Used for serialization
+     */
+    private $_data = array();
+
+    /**
+     * Serialize to an array
+     *
+     * Array will be priority => data pairs
+     * 
+     * @return array
+     */
+    public function toArray()
+    {
+        $this->setExtractFlags(self::EXTR_BOTH);
+        $array = array();
+        while ($this->valid()) {
+            $array[] = $this->current();
+            $this->next();
+        }
+        $this->setExtractFlags(self::EXTR_DATA);
+
+        // Iterating through a priority queue removes items
+        foreach ($array as $item) {
+            $this->insert($item['data'], $item['priority']);
+        }
+
+        // Return only the data
+        $return = array();
+        foreach ($array as $item) {
+            $return[$item['priority']] = $item['data'];
+        }
+
+        return $return;
+    }
+
+    /**
+     * Serialize
+     * 
+     * @return array
+     */
+    public function __sleep()
+    {
+        $this->_data = array();
+        $this->setExtractFlags(self::EXTR_BOTH);
+        while ($this->valid()) {
+            $this->_data[] = $this->current();
+            $this->next();
+        }
+        $this->setExtractFlags(self::EXTR_DATA);
+
+        // Iterating through a priority queue removes items
+        foreach ($this->_data as $item) {
+            $this->insert($item['data'], $item['priority']);
+        }
+
+        return array('_data');
+    }
+
+    /**
+     * Deserialize
+     * 
+     * @return void
+     */
+    public function __wakeup()
+    {
+        foreach ($this->_data as $item) {
+            $this->insert($item['data'], $item['priority']);
+        }
+        $this->_data = array();
+    }
+}

src/SplQueue.php

@@ -0,0 +1,48 @@
+<?php
+namespace Zend\Stdlib;
+
+class SplQueue extends \SplQueue
+{
+    /**
+     * @var array Used for serialization
+     */
+    private $_data = array();
+
+    /**
+     * Return an array representing the queue
+     * 
+     * @return array
+     */
+    public function toArray()
+    {
+        $array = array();
+        foreach ($this as $item) {
+            $array[] = $item;
+        }
+        return $array;
+    }
+
+    /**
+     * Serialize
+     * 
+     * @return array
+     */
+    public function __sleep()
+    {
+        $this->_data = $this->toArray();
+        return array('_data');
+    }
+
+    /**
+     * Unserialize
+     * 
+     * @return void
+     */
+    public function __wakeup()
+    {
+        foreach ($this->_data as $item) {
+            $this->push($item);
+        }
+        $this->_data = array();
+    }
+}

src/SplStack.php

@@ -0,0 +1,48 @@
+<?php
+namespace Zend\Stdlib;
+
+class SplStack extends \SplStack
+{
+    /**
+     * @var array Used in serialization
+     */
+    private $_data = array();
+
+    /**
+     * Serialize to an array representing the stack
+     * 
+     * @return void
+     */
+    public function toArray()
+    {
+        $array = array();
+        foreach ($this as $item) {
+            $array[] = $item;
+        }
+        return $array;
+    }
+
+    /**
+     * Serialize
+     * 
+     * @return array
+     */
+    public function __sleep()
+    {
+        $this->_data = $this->toArray();
+        return array('_data');
+    }
+
+    /**
+     * Unserialize
+     * 
+     * @return void
+     */
+    public function __wakeup()
+    {
+        foreach ($this->_data as $item) {
+            $this->unshift($item);
+        }
+        $this->_data = array();
+    }
+}

test/SplPriorityQueueTest.php

@@ -0,0 +1,46 @@
+<?php
+namespace ZendTest\Stdlib;
+
+use Zend\Stdlib\SplPriorityQueue;
+
+class SplPriorityQueueTest extends \PHPUnit_Framework_TestCase
+{
+    public function setUp()
+    {
+        $this->queue = new SplPriorityQueue();
+        $this->queue->insert('foo', 3);
+        $this->queue->insert('bar', 4);
+        $this->queue->insert('baz', 2);
+        $this->queue->insert('bat', 1);
+    }
+
+    public function testSerializationAndDeserializationShouldMaintainState()
+    {
+        $s = serialize($this->queue);
+        $unserialized = unserialize($s);
+        $count = count($this->queue);
+        $this->assertSame($count, count($unserialized), 'Expected count ' . $count . '; received ' . count($unserialized));
+
+        $expected = array();
+        foreach ($this->queue as $item) {
+            $expected[] = $item;
+        }
+        $test = array();
+        foreach ($unserialized as $item) {
+            $test[] = $item;
+        }
+        $this->assertSame($expected, $test, 'Expected: ' . var_export($expected, 1) . "\nReceived:" . var_export($test, 1));
+    }
+
+    public function testCanRetrieveQueueAsArray()
+    {
+        $expected = array(
+            4 => 'bar', 
+            3 => 'foo', 
+            2 => 'baz', 
+            1 => 'bat',
+        );
+        $test     = $this->queue->toArray();
+        $this->assertSame($expected, $test, var_export($test, 1));
+    }
+}

test/SplQueueTest.php

@@ -0,0 +1,39 @@
+<?php
+namespace ZendTest\Stdlib;
+
+use Zend\Stdlib\SplQueue;
+
+class SplQueueTest extends \PHPUnit_Framework_TestCase
+{
+    public function setUp()
+    {
+        $this->queue = new SplQueue();
+        $this->queue->push('foo');
+        $this->queue->push('bar');
+        $this->queue->push('baz');
+    }
+
+    public function testSerializationAndDeserializationShouldMaintainState()
+    {
+        $s = serialize($this->queue);
+        $unserialized = unserialize($s);
+        $count = count($this->queue);
+        $this->assertSame($count, count($unserialized));
+
+        $expected = array();
+        foreach ($this->queue as $item) {
+            $expected[] = $item;
+        }
+        $test = array();
+        foreach ($unserialized as $item) {
+            $test[] = $item;
+        }
+        $this->assertSame($expected, $test);
+    }
+
+    public function testCanRetrieveQueueAsArray()
+    {
+        $expected = array('foo', 'bar', 'baz');
+        $this->assertSame($expected, $this->queue->toArray());
+    }
+}

test/SplStackTest.php

@@ -0,0 +1,41 @@
+<?php
+namespace ZendTest\Stdlib;
+
+use Zend\Stdlib\SplStack;
+
+class SplStackTest extends \PHPUnit_Framework_TestCase
+{
+    public function setUp()
+    {
+        $this->stack = new SplStack();
+        $this->stack->push('foo');
+        $this->stack->push('bar');
+        $this->stack->push('baz');
+        $this->stack->push('bat');
+    }
+
+    public function testSerializationAndDeserializationShouldMaintainState()
+    {
+        $s = serialize($this->stack);
+        $unserialized = unserialize($s);
+        $count = count($this->stack);
+        $this->assertSame($count, count($unserialized));
+
+        $expected = array();
+        foreach ($this->stack as $item) {
+            $expected[] = $item;
+        }
+        $test = array();
+        foreach ($unserialized as $item) {
+            $test[] = $item;
+        }
+        $this->assertSame($expected, $test);
+    }
+
+    public function testCanRetrieveQueueAsArray()
+    {
+        $expected = array('bat', 'baz', 'bar', 'foo');
+        $test     = $this->stack->toArray();
+        $this->assertSame($expected, $test, var_export($test, 1));
+    }
+}