add support for Gaufrette cache

composer.json

@@ -27,6 +27,9 @@
     "require-dev": {
         "phpunit/phpunit":  ">=3.6.0"
     },
+    "suggest": {
+        "knplabs/gaufrette": "Needed for optional Gaufrette cache"
+    },
     "autoload": {
         "psr-0": { "Github\\": "lib/" }
     },

lib/Github/HttpClient/Cache/GaufretteCache.php

@@ -0,0 +1,57 @@
+<?php
+
+namespace Github\HttpClient\Cache;
+
+use Guzzle\Http\Message\Response;
+use Gaufrette\Filesystem;
+
+/**
+ * Gaufrette Cache
+ *
+ * @author Massimiliano Arione <massimiliano.arione@bee-lab.net>
+ */
+class GaufretteCache implements CacheInterface
+{
+    /**
+     * @var Filesystem
+     */
+    protected $filesystem;
+
+    /**
+     * @param Filesystem $filesystem
+     */
+    public function __construct(Filesystem $filesystem)
+    {
+        $this->filesystem = $filesystem;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function get($id)
+    {
+        $content = $this->filesystem->read($id);
+
+        return unserialize($content);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function set($id, Response $response)
+    {
+        $this->filesystem->write($id, serialize($response), true);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getModifiedSince($id)
+    {
+        if ($this->filesystem->has($id)) {
+            return $this->filesystem->mtime($id);
+        }
+
+        return null;
+    }
+}

test/Github/Tests/HttpClient/Cache/GaufretteCacheTest.php

@@ -0,0 +1,84 @@
+<?php
+
+namespace Github\Tests\HttpClient\Cache;
+
+use Guzzle\Http\Message\Response;
+use Github\HttpClient\Cache\GaufretteCache;
+
+class GaufretteCacheTest extends \PHPUnit_Framework_TestCase
+{
+    public function setUp()
+    {
+        if (!class_exists('Gaufrette\Filesystem')) {
+            $this->markTestSkipped('Gaufrette not installed.');
+        }
+    }
+
+    /**
+     * @test
+     */
+    public function shouldStoreAResponseForAGivenKey()
+    {
+        $response = new Response(200);
+        $filesystem = $this->getMockBuilder('Gaufrette\Filesystem')->disableOriginalConstructor()->getMock();
+        $filesystem
+            ->expects($this->once())
+            ->method('write')
+            ->with('test', serialize($response))
+        ;
+        $filesystem
+            ->expects($this->once())
+            ->method('read')
+            ->with('test')
+            ->will($this->returnValue('a:0:{}'))
+        ;
+
+        $cache = new GaufretteCache($filesystem);
+        $cache->set('test', $response);
+        $this->assertNotNull($cache->get('test'));
+    }
+
+    /**
+     * @test
+     */
+    public function shouldGetATimestampForExistingFile()
+    {
+        $response = new Response(200);
+        $filesystem = $this->getMockBuilder('Gaufrette\Filesystem')->disableOriginalConstructor()->getMock();
+        $filesystem
+            ->expects($this->once())
+            ->method('has')
+            ->with('test')
+            ->will($this->returnValue(true))
+        ;
+        $filesystem
+            ->expects($this->once())
+            ->method('mtime')
+            ->with('test')
+            ->will($this->returnValue(100))
+        ;
+
+        $cache = new GaufretteCache($filesystem);
+        $cache->set('test', new Response(200));
+
+        $this->assertInternalType('int', $cache->getModifiedSince('test'));
+    }
+
+    /**
+     * @test
+     */
+    public function shouldNotGetATimestampForInexistingFile()
+    {
+        $filesystem = $this->getMockBuilder('Gaufrette\Filesystem')->disableOriginalConstructor()->getMock();
+        $filesystem
+            ->expects($this->once())
+            ->method('has')
+            ->with('test2')
+            ->will($this->returnValue(false))
+        ;
+
+        $cache = new GaufretteCache($filesystem);
+
+        $this->assertNull($cache->getModifiedSince('test2'));
+    }
+}