class ChainedFastBackendTest

class ChainedFastBackendTest extends UnitTestCase {
    
    /**
     * The consistent cache backend.
     *
     * @var \Drupal\Core\Cache\CacheBackendInterface
     */
    protected $consistentCache;
    
    /**
     * The fast cache backend.
     *
     * @var \Drupal\Core\Cache\CacheBackendInterface
     */
    protected $fastCache;
    
    /**
     * The cache bin.
     *
     * @var string
     */
    protected $bin;
    
    /**
     * Tests a get() on the fast backend, with no hit on the consistent backend.
     */
    public function testGetDoesNotHitConsistentBackend() {
        $consistent_cache = $this->createMock('Drupal\\Core\\Cache\\CacheBackendInterface');
        $timestamp_cid = ChainedFastBackend::LAST_WRITE_TIMESTAMP_PREFIX . 'cache_foo';
        // Use the request time because that is what we will be comparing against.
        $timestamp_item = (object) [
            'cid' => $timestamp_cid,
            'data' => (int) $_SERVER['REQUEST_TIME'] - 60,
        ];
        $consistent_cache->expects($this->once())
            ->method('get')
            ->with($timestamp_cid)
            ->willReturn($timestamp_item);
        $consistent_cache->expects($this->never())
            ->method('getMultiple');
        $fast_cache = new MemoryBackend();
        $fast_cache->set('foo', 'baz');
        $chained_fast_backend = new ChainedFastBackend($consistent_cache, $fast_cache, 'foo');
        $this->assertEquals('baz', $chained_fast_backend->get('foo')->data);
    }
    
    /**
     * Tests a fast cache miss gets data from the consistent cache backend.
     */
    public function testFallThroughToConsistentCache() {
        $timestamp_item = (object) [
            'cid' => ChainedFastBackend::LAST_WRITE_TIMESTAMP_PREFIX . 'cache_foo',
            // Time travel is easy.
'data' => time() + 60,
        ];
        $cache_item = (object) [
            'cid' => 'foo',
            'data' => 'baz',
            'created' => time(),
            'expire' => time() + 3600,
            'tags' => [
                'tag',
            ],
        ];
        $consistent_cache = $this->createMock('Drupal\\Core\\Cache\\CacheBackendInterface');
        $fast_cache = $this->createMock('Drupal\\Core\\Cache\\CacheBackendInterface');
        // We should get a call for the timestamp on the consistent backend.
        $consistent_cache->expects($this->once())
            ->method('get')
            ->with($timestamp_item->cid)
            ->willReturn($timestamp_item);
        // We should get a call for the cache item on the consistent backend.
        $consistent_cache->expects($this->once())
            ->method('getMultiple')
            ->with([
            $cache_item->cid,
        ])
            ->willReturn([
            $cache_item->cid => $cache_item,
        ]);
        // We should get a call for the cache item on the fast backend.
        $fast_cache->expects($this->once())
            ->method('getMultiple')
            ->with([
            $cache_item->cid,
        ])
            ->willReturn([
            $cache_item->cid => $cache_item,
        ]);
        // We should get a call to set the cache item on the fast backend.
        $fast_cache->expects($this->once())
            ->method('set')
            ->with($cache_item->cid, $cache_item->data, $cache_item->expire);
        $chained_fast_backend = new ChainedFastBackend($consistent_cache, $fast_cache, 'foo');
        $this->assertEquals('baz', $chained_fast_backend->get('foo')->data);
    }

}