feature #20858 [Cache] Simple Memcached Adapter (robfrawley)

This PR was merged into the 3.3-dev branch.

Discussion
----------

[Cache] Simple Memcached Adapter

| Q             | A
| ------------- | ---
| Branch?       | master
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets |
| License       | MIT
| Doc PR        |
| Related PRs | #20863, ~~#20752~~

Commits
-------

12de2ae memcached cache pool adapter

src/Symfony/Component/Cache/Adapter/MemcachedAdapter.php

@@ -0,0 +1,80 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Cache\Adapter;
+
+/**
+ * @author Rob Frawley 2nd <rmf@src.run>
+ */
+class MemcachedAdapter extends AbstractAdapter
+{
+    private $client;
+
+    public static function isSupported()
+    {
+        return extension_loaded('memcached') && version_compare(phpversion('memcached'), '2.2.0', '>=');
+    }
+
+    public function __construct(\Memcached $client, $namespace = '', $defaultLifetime = 0)
+    {
+        parent::__construct($namespace, $defaultLifetime);
+        $this->client = $client;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function doSave(array $values, $lifetime)
+    {
+        return $this->client->setMulti($values, $lifetime)
+            && $this->client->getResultCode() === \Memcached::RES_SUCCESS;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function doFetch(array $ids)
+    {
+        return $this->client->getMulti($ids);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function doHave($id)
+    {
+        return $this->client->get($id) !== false
+            || $this->client->getResultCode() === \Memcached::RES_SUCCESS;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function doDelete(array $ids)
+    {
+        $toDelete = count($ids);
+        foreach ($this->client->deleteMulti($ids) as $result) {
+            if (\Memcached::RES_SUCCESS === $result || \Memcached::RES_NOTFOUND === $result) {
+                --$toDelete;
+            }
+        }
+
+        return 0 === $toDelete;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function doClear($namespace)
+    {
+        return $this->client->flush();
+    }
+}

src/Symfony/Component/Cache/Tests/Adapter/MemcachedAdapterTest.php

@@ -0,0 +1,50 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Cache\Tests\Adapter;
+
+use Symfony\Component\Cache\Adapter\MemcachedAdapter;
+
+class MemcachedAdapterTest extends AdapterTestCase
+{
+    protected $skippedTests = array(
+        'testExpiration' => 'Testing expiration slows down the test suite',
+        'testHasItemReturnsFalseWhenDeferredItemIsExpired' => 'Testing expiration slows down the test suite',
+        'testDefaultLifeTime' => 'Testing expiration slows down the test suite',
+    );
+
+    private static $client;
+
+    public static function setupBeforeClass()
+    {
+        if (!MemcachedAdapter::isSupported()) {
+            self::markTestSkipped('Extension memcached >=2.2.0 required.');
+        }
+
+        self::$client = new \Memcached();
+        self::$client->addServers(array(array(
+            getenv('MEMCACHED_HOST') ?: '127.0.0.1',
+            getenv('MEMCACHED_PORT') ?: 11211,
+        )));
+
+        parent::setupBeforeClass();
+    }
+
+    public function createCachePool($defaultLifetime = 0)
+    {
+        return new MemcachedAdapter(self::$client, str_replace('\\', '.', __CLASS__), $defaultLifetime);
+    }
+
+    public function testIsSupported()
+    {
+        $this->assertTrue(MemcachedAdapter::isSupported());
+    }
+}