bug #19042 [Cache] Fix double fetch in ProxyAdapter (nicolas-grekas)

This PR was merged into the 3.1 branch.

Discussion
----------

[Cache] Fix double fetch in ProxyAdapter

| Q             | A
| ------------- | ---
| Branch?       | 3.1
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | -
| License       | MIT
| Doc PR        | -

Commits
-------

040f53d [Cache] Fix double fetch in ProxyAdapter

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

@@ -42,7 +42,7 @@ abstract class AbstractAdapter implements AdapterInterface, LoggerAwareInterface
 
                 return $item;
             },
-            $this,
+            null,
             CacheItem::class
         );
         $this->mergeByLifetime = \Closure::bind(
@@ -63,7 +63,7 @@ abstract class AbstractAdapter implements AdapterInterface, LoggerAwareInterface
 
                 return $byLifetime;
             },
-            $this,
+            null,
             CacheItem::class
         );
     }

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

@@ -45,7 +45,7 @@ class ArrayAdapter implements AdapterInterface, LoggerAwareInterface
 
                 return $item;
             },
-            $this,
+            null,
             CacheItem::class
         );
     }
@@ -132,9 +132,9 @@ class ArrayAdapter implements AdapterInterface, LoggerAwareInterface
             return false;
         }
         $item = (array) $item;
-        $key = $item[CacheItem::CAST_PREFIX.'key'];
-        $value = $item[CacheItem::CAST_PREFIX.'value'];
-        $expiry = $item[CacheItem::CAST_PREFIX.'expiry'];
+        $key = $item["\0*\0key"];
+        $value = $item["\0*\0value"];
+        $expiry = $item["\0*\0expiry"];
 
         if (null !== $expiry && $expiry <= time()) {
             $this->deleteItem($key);

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

@@ -62,7 +62,7 @@ class ChainAdapter implements AdapterInterface
                 $adapter->save($item);
                 $item->defaultLifetime = $origDefaultLifetime;
             },
-            $this,
+            null,
             CacheItem::class
         );
     }

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

@@ -24,23 +24,28 @@ class ProxyAdapter implements AdapterInterface
     private $namespace;
     private $namespaceLen;
     private $createCacheItem;
+    private $poolHash;
 
     public function __construct(CacheItemPoolInterface $pool, $namespace = '', $defaultLifetime = 0)
     {
         $this->pool = $pool;
+        $this->poolHash = $poolHash = spl_object_hash($pool);
         $this->namespace = '' === $namespace ? '' : $this->getId($namespace);
         $this->namespaceLen = strlen($namespace);
         $this->createCacheItem = \Closure::bind(
-            function ($key, $value, $isHit) use ($defaultLifetime) {
+            function ($key, $innerItem) use ($defaultLifetime, $poolHash) {
                 $item = new CacheItem();
                 $item->key = $key;
-                $item->value = $value;
-                $item->isHit = $isHit;
+                $item->value = $innerItem->get();
+                $item->isHit = $innerItem->isHit();
                 $item->defaultLifetime = $defaultLifetime;
+                $item->innerItem = $innerItem;
+                $item->poolHash = $poolHash;
+                $innerItem->set(null);
 
                 return $item;
             },
-            $this,
+            null,
             CacheItem::class
         );
     }
@@ -53,7 +58,7 @@ class ProxyAdapter implements AdapterInterface
         $f = $this->createCacheItem;
         $item = $this->pool->getItem($this->getId($key));
 
-        return $f($key, $item->get(), $item->isHit());
+        return $f($key, $item);
     }
 
     /**
@@ -138,12 +143,12 @@ class ProxyAdapter implements AdapterInterface
             return false;
         }
         $item = (array) $item;
-        $expiry = $item[CacheItem::CAST_PREFIX.'expiry'];
-        $poolItem = $this->pool->getItem($this->namespace.$item[CacheItem::CAST_PREFIX.'key']);
-        $poolItem->set($item[CacheItem::CAST_PREFIX.'value']);
-        $poolItem->expiresAt(null !== $expiry ? \DateTime::createFromFormat('U', $expiry) : null);
+        $expiry = $item["\0*\0expiry"];
+        $innerItem = $item["\0*\0poolHash"] === $this->poolHash ? $item["\0*\0innerItem"] : $this->pool->getItem($this->namespace.$item["\0*\0key"]);
+        $innerItem->set($item["\0*\0value"]);
+        $innerItem->expiresAt(null !== $expiry ? \DateTime::createFromFormat('U', $expiry) : null);
 
-        return $this->pool->$method($poolItem);
+        return $this->pool->$method($innerItem);
     }
 
     private function generateItems($items)
@@ -155,7 +160,7 @@ class ProxyAdapter implements AdapterInterface
                 $key = substr($key, $this->namespaceLen);
             }
 
-            yield $key => $f($key, $item->get(), $item->isHit());
+            yield $key => $f($key, $item);
         }
     }
 

src/Symfony/Component/Cache/CacheItem.php

@@ -20,16 +20,13 @@ use Symfony\Component\Cache\Exception\InvalidArgumentException;
  */
 final class CacheItem implements CacheItemInterface
 {
-    /**
-     * @internal
-     */
-    const CAST_PREFIX = "\0Symfony\Component\Cache\CacheItem\0";
-
-    private $key;
-    private $value;
-    private $isHit;
-    private $expiry;
-    private $defaultLifetime;
+    protected $key;
+    protected $value;
+    protected $isHit;
+    protected $expiry;
+    protected $defaultLifetime;
+    protected $innerItem;
+    protected $poolHash;
 
     /**
      * {@inheritdoc}

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

@@ -12,8 +12,10 @@
 namespace Symfony\Component\Cache\Tests\Adapter;
 
 use Cache\IntegrationTests\CachePoolTest;
+use Psr\Cache\CacheItemInterface;
 use Symfony\Component\Cache\Adapter\ArrayAdapter;
 use Symfony\Component\Cache\Adapter\ProxyAdapter;
+use Symfony\Component\Cache\CacheItem;
 
 /**
  * @group time-sensitive
@@ -29,4 +31,41 @@ class ProxyAdapterTest extends CachePoolTest
     {
         return new ProxyAdapter(new ArrayAdapter());
     }
+
+    /**
+     * @expectedException Exception
+     * @expectedExceptionMessage OK bar
+     */
+    public function testProxyfiedItem()
+    {
+        $item = new CacheItem();
+        $pool = new ProxyAdapter(new TestingArrayAdapter($item));
+
+        $proxyItem = $pool->getItem('foo');
+
+        $this->assertFalse($proxyItem === $item);
+        $pool->save($proxyItem->set('bar'));
+    }
+}
+
+class TestingArrayAdapter extends ArrayAdapter
+{
+    private $item;
+
+    public function __construct(CacheItemInterface $item)
+    {
+        $this->item = $item;
+    }
+
+    public function getItem($key)
+    {
+        return $this->item;
+    }
+
+    public function save(CacheItemInterface $item)
+    {
+        if ($item === $this->item) {
+            throw new \Exception('OK '.$item->get());
+        }
+    }
 }