diff --git a/src/Symfony/Component/Cache/Adapter/AbstractAdapter.php b/src/Symfony/Component/Cache/Adapter/AbstractAdapter.php
index a6da1952a57bd..543bd2da1fdfc 100644
--- a/src/Symfony/Component/Cache/Adapter/AbstractAdapter.php
+++ b/src/Symfony/Component/Cache/Adapter/AbstractAdapter.php
@@ -12,7 +12,6 @@
namespace Symfony\Component\Cache\Adapter;
use Psr\Cache\CacheItemInterface;
-use Psr\Cache\CacheItemPoolInterface;
use Psr\Log\LoggerAwareInterface;
use Psr\Log\LoggerAwareTrait;
use Symfony\Component\Cache\CacheItem;
@@ -21,7 +20,7 @@
/**
* @author Nicolas Grekas
*/
-abstract class AbstractAdapter implements CacheItemPoolInterface, LoggerAwareInterface
+abstract class AbstractAdapter implements AdapterInterface, LoggerAwareInterface
{
use LoggerAwareTrait;
diff --git a/src/Symfony/Component/Cache/Adapter/AdapterInterface.php b/src/Symfony/Component/Cache/Adapter/AdapterInterface.php
new file mode 100644
index 0000000000000..85a0da80db079
--- /dev/null
+++ b/src/Symfony/Component/Cache/Adapter/AdapterInterface.php
@@ -0,0 +1,24 @@
+
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Cache\Adapter;
+
+use Psr\Cache\CacheItemPoolInterface;
+use Symfony\Component\Cache\CacheItem;
+
+/**
+ * Interface for adapters managing instances of Symfony's {@see CacheItem}.
+ *
+ * @author Kévin Dunglas
+ */
+interface AdapterInterface extends CacheItemPoolInterface
+{
+}
diff --git a/src/Symfony/Component/Cache/Adapter/ArrayAdapter.php b/src/Symfony/Component/Cache/Adapter/ArrayAdapter.php
index e7f69807e8f08..d00488911c838 100644
--- a/src/Symfony/Component/Cache/Adapter/ArrayAdapter.php
+++ b/src/Symfony/Component/Cache/Adapter/ArrayAdapter.php
@@ -12,7 +12,6 @@
namespace Symfony\Component\Cache\Adapter;
use Psr\Cache\CacheItemInterface;
-use Psr\Cache\CacheItemPoolInterface;
use Psr\Log\LoggerAwareInterface;
use Psr\Log\LoggerAwareTrait;
use Symfony\Component\Cache\CacheItem;
@@ -21,7 +20,7 @@
/**
* @author Nicolas Grekas
*/
-class ArrayAdapter implements CacheItemPoolInterface, LoggerAwareInterface
+class ArrayAdapter implements AdapterInterface, LoggerAwareInterface
{
use LoggerAwareTrait;
diff --git a/src/Symfony/Component/Cache/Adapter/ChainAdapter.php b/src/Symfony/Component/Cache/Adapter/ChainAdapter.php
new file mode 100644
index 0000000000000..013ce97839a68
--- /dev/null
+++ b/src/Symfony/Component/Cache/Adapter/ChainAdapter.php
@@ -0,0 +1,226 @@
+
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Cache\Adapter;
+
+use Psr\Cache\CacheItemInterface;
+use Psr\Cache\CacheItemPoolInterface;
+use Symfony\Component\Cache\CacheItem;
+use Symfony\Component\Cache\Exception\InvalidArgumentException;
+
+/**
+ * Chains several adapters together.
+ *
+ * Cached items are fetched from the first adapter having them in its data store.
+ * They are saved and deleted in all adapters at once.
+ *
+ * @author Kévin Dunglas
+ */
+class ChainAdapter implements AdapterInterface
+{
+ private $adapters = array();
+ private $saveUp;
+
+ /**
+ * @param CacheItemPoolInterface[] $adapters The ordered list of adapters used to fetch cached items.
+ * @param int $maxLifetime The max lifetime of items propagated from lower adapters to upper ones.
+ */
+ public function __construct(array $adapters, $maxLifetime = 0)
+ {
+ if (!$adapters) {
+ throw new InvalidArgumentException('At least one adapter must be specified.');
+ }
+
+ foreach ($adapters as $adapter) {
+ if (!$adapter instanceof CacheItemPoolInterface) {
+ throw new InvalidArgumentException(sprintf('The class "%s" does not implement the "%s" interface.', get_class($adapter), CacheItemPoolInterface::class));
+ }
+
+ if ($adapter instanceof AdapterInterface) {
+ $this->adapters[] = $adapter;
+ } else {
+ $this->adapters[] = new ProxyAdapter($adapter);
+ }
+ }
+
+ $this->saveUp = \Closure::bind(
+ function ($adapter, $item) use ($maxLifetime) {
+ $origDefaultLifetime = $item->defaultLifetime;
+
+ if (0 < $maxLifetime && ($origDefaultLifetime <= 0 || $maxLifetime < $origDefaultLifetime)) {
+ $item->defaultLifetime = $maxLifetime;
+ }
+
+ $adapter->save($item);
+ $item->defaultLifetime = $origDefaultLifetime;
+ },
+ $this,
+ CacheItem::class
+ );
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function getItem($key)
+ {
+ $saveUp = $this->saveUp;
+
+ foreach ($this->adapters as $i => $adapter) {
+ $item = $adapter->getItem($key);
+
+ if ($item->isHit()) {
+ while (0 <= --$i) {
+ $saveUp($this->adapters[$i], $item);
+ }
+
+ return $item;
+ }
+ }
+
+ return $item;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function getItems(array $keys = array())
+ {
+ return $this->generateItems($this->adapters[0]->getItems($keys), 0);
+ }
+
+ private function generateItems($items, $adapterIndex)
+ {
+ $missing = array();
+ $nextAdapterIndex = $adapterIndex + 1;
+ $nextAdapter = isset($this->adapters[$nextAdapterIndex]) ? $this->adapters[$nextAdapterIndex] : null;
+
+ foreach ($items as $k => $item) {
+ if (!$nextAdapter || $item->isHit()) {
+ yield $k => $item;
+ } else {
+ $missing[] = $k;
+ }
+ }
+
+ if ($missing) {
+ $saveUp = $this->saveUp;
+ $adapter = $this->adapters[$adapterIndex];
+ $items = $this->generateItems($nextAdapter->getItems($missing), $nextAdapterIndex);
+
+ foreach ($items as $k => $item) {
+ if ($item->isHit()) {
+ $saveUp($adapter, $item);
+ }
+
+ yield $k => $item;
+ }
+ }
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function hasItem($key)
+ {
+ foreach ($this->adapters as $adapter) {
+ if ($adapter->hasItem($key)) {
+ return true;
+ }
+ }
+
+ return false;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function clear()
+ {
+ $cleared = true;
+
+ foreach ($this->adapters as $adapter) {
+ $cleared = $adapter->clear() && $cleared;
+ }
+
+ return $cleared;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function deleteItem($key)
+ {
+ $deleted = true;
+
+ foreach ($this->adapters as $adapter) {
+ $deleted = $adapter->deleteItem($key) && $deleted;
+ }
+
+ return $deleted;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function deleteItems(array $keys)
+ {
+ $deleted = true;
+
+ foreach ($this->adapters as $adapter) {
+ $deleted = $adapter->deleteItems($keys) && $deleted;
+ }
+
+ return $deleted;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function save(CacheItemInterface $item)
+ {
+ $saved = true;
+
+ foreach ($this->adapters as $adapter) {
+ $saved = $adapter->save($item) && $saved;
+ }
+
+ return $saved;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function saveDeferred(CacheItemInterface $item)
+ {
+ $saved = true;
+
+ foreach ($this->adapters as $adapter) {
+ $saved = $adapter->saveDeferred($item) && $saved;
+ }
+
+ return $saved;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function commit()
+ {
+ $committed = true;
+
+ foreach ($this->adapters as $adapter) {
+ $committed = $adapter->commit() && $committed;
+ }
+
+ return $committed;
+ }
+}
diff --git a/src/Symfony/Component/Cache/Adapter/ProxyAdapter.php b/src/Symfony/Component/Cache/Adapter/ProxyAdapter.php
index 3bce3cb5bb612..83c3f1baea055 100644
--- a/src/Symfony/Component/Cache/Adapter/ProxyAdapter.php
+++ b/src/Symfony/Component/Cache/Adapter/ProxyAdapter.php
@@ -19,7 +19,7 @@
/**
* @author Nicolas Grekas
*/
-class ProxyAdapter implements CacheItemPoolInterface
+class ProxyAdapter implements AdapterInterface
{
private $pool;
private $namespace;
diff --git a/src/Symfony/Component/Cache/Tests/Adapter/ChainAdapterTest.php b/src/Symfony/Component/Cache/Tests/Adapter/ChainAdapterTest.php
new file mode 100644
index 0000000000000..e9dce9ee8d0e7
--- /dev/null
+++ b/src/Symfony/Component/Cache/Tests/Adapter/ChainAdapterTest.php
@@ -0,0 +1,54 @@
+
+ *
+ * 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 Cache\IntegrationTests\CachePoolTest;
+use Symfony\Component\Cache\Adapter\ApcuAdapter;
+use Symfony\Component\Cache\Adapter\ArrayAdapter;
+use Symfony\Component\Cache\Adapter\ChainAdapter;
+use Symfony\Component\Cache\Tests\Fixtures\ExternalAdapter;
+
+/**
+ * @author Kévin Dunglas
+ */
+class ChainAdapterTest extends CachePoolTest
+{
+ public function createCachePool()
+ {
+ if (defined('HHVM_VERSION')) {
+ $this->skippedTests['testDeferredSaveWithoutCommit'] = 'Fails on HHVM';
+ }
+ if (!function_exists('apcu_fetch') || !ini_get('apc.enabled') || ('cli' === PHP_SAPI && !ini_get('apc.enable_cli'))) {
+ $this->markTestSkipped('APCu extension is required.');
+ }
+
+ return new ChainAdapter(array(new ArrayAdapter(), new ExternalAdapter(), new ApcuAdapter()));
+ }
+
+ /**
+ * @expectedException \Symfony\Component\Cache\Exception\InvalidArgumentException
+ * @expectedExceptionMessage At least one adapter must be specified.
+ */
+ public function testEmptyAdaptersException()
+ {
+ new ChainAdapter(array());
+ }
+
+ /**
+ * @expectedException \Symfony\Component\Cache\Exception\InvalidArgumentException
+ * @expectedExceptionMessage The class "stdClass" does not implement
+ */
+ public function testInvalidAdapterException()
+ {
+ new ChainAdapter(array(new \stdClass()));
+ }
+}
diff --git a/src/Symfony/Component/Cache/Tests/Fixtures/ExternalAdapter.php b/src/Symfony/Component/Cache/Tests/Fixtures/ExternalAdapter.php
new file mode 100644
index 0000000000000..493906ea0cccc
--- /dev/null
+++ b/src/Symfony/Component/Cache/Tests/Fixtures/ExternalAdapter.php
@@ -0,0 +1,76 @@
+
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Cache\Tests\Fixtures;
+
+use Psr\Cache\CacheItemInterface;
+use Psr\Cache\CacheItemPoolInterface;
+use Symfony\Component\Cache\Adapter\ArrayAdapter;
+
+/**
+ * Adapter not implementing the {@see \Symfony\Component\Cache\Adapter\AdapterInterface}.
+ *
+ * @author Kévin Dunglas
+ */
+class ExternalAdapter implements CacheItemPoolInterface
+{
+ private $cache;
+
+ public function __construct()
+ {
+ $this->cache = new ArrayAdapter();
+ }
+
+ public function getItem($key)
+ {
+ return $this->cache->getItem($key);
+ }
+
+ public function getItems(array $keys = array())
+ {
+ return $this->cache->getItems($keys);
+ }
+
+ public function hasItem($key)
+ {
+ return $this->cache->hasItem($key);
+ }
+
+ public function clear()
+ {
+ return $this->cache->clear();
+ }
+
+ public function deleteItem($key)
+ {
+ return $this->cache->deleteItem($key);
+ }
+
+ public function deleteItems(array $keys)
+ {
+ return $this->cache->deleteItems($keys);
+ }
+
+ public function save(CacheItemInterface $item)
+ {
+ return $this->cache->save($item);
+ }
+
+ public function saveDeferred(CacheItemInterface $item)
+ {
+ return $this->cache->saveDeferred($item);
+ }
+
+ public function commit()
+ {
+ return $this->cache->commit();
+ }
+}