symfony · nicolas-grekas · Jan 27, 2020 · Jan 16, 2020
diff --git a/src/Symfony/Component/Cache/Adapter/ArrayAdapter.php b/src/Symfony/Component/Cache/Adapter/ArrayAdapter.php
@@ -15,10 +15,15 @@
 use Psr\Log\LoggerAwareInterface;
 use Psr\Log\LoggerAwareTrait;
 use Symfony\Component\Cache\CacheItem;
+use Symfony\Component\Cache\Exception\InvalidArgumentException;
 use Symfony\Component\Cache\ResettableInterface;
 use Symfony\Contracts\Cache\CacheInterface;

 /**
+ * An in-memory cache storage.
+ *
+ * Acts as a least-recently-used (LRU) storage when configured with a maximum number of items.
+ *
 * @author Nicolas Grekas <p@tchwork.com>
 */
 class ArrayAdapter implements AdapterInterface, CacheInterface, LoggerAwareInterface, ResettableInterface
@@ -29,13 +34,25 @@ class ArrayAdapter implements AdapterInterface, CacheInterface, LoggerAwareInter
    private $values = [];
    private $expiries = [];
    private $createCacheItem;
+    private $maxLifetime;
+    private $maxItems;

    /**
     * @param bool $storeSerialized Disabling serialization can lead to cache corruptions when storing mutable values but increases performance otherwise
     */
-    public function __construct(int $defaultLifetime = 0, bool $storeSerialized = true)
+    public function __construct(int $defaultLifetime = 0, bool $storeSerialized = true, int $maxLifetime = 0, int $maxItems = 0)
    {
+        if (0 > $maxLifetime) {
+            throw new InvalidArgumentException(sprintf('Argument $maxLifetime must be a positive integer, %d passed.', $maxLifetime));
+        }
+
+        if (0 > $maxItems) {
+            throw new InvalidArgumentException(sprintf('Argument $maxItems must be a positive integer, %d passed.', $maxItems));
+        }
+
        $this->storeSerialized = $storeSerialized;
+        $this->maxLifetime = $maxLifetime;
+        $this->maxItems = $maxItems;
        $this->createCacheItem = \Closure::bind(
            static function ($key, $value, $isHit) use ($defaultLifetime) {
                $item = new CacheItem();
@@ -84,6 +101,13 @@ public function delete(string $key): bool
    public function hasItem($key)
    {
        if (\is_string($key) && isset($this->expiries[$key]) && $this->expiries[$key] > microtime(true)) {
+            if ($this->maxItems) {
+                // Move the item last in the storage
+                $value = $this->values[$key];
+                unset($this->values[$key]);
+                $this->values[$key] = $value;
+            }
+
            return true;
        }
        CacheItem::validateKey($key);
@@ -97,7 +121,12 @@ public function hasItem($key)
    public function getItem($key)
    {
        if (!$isHit = $this->hasItem($key)) {
-            $this->values[$key] = $value = null;
+            $value = null;
+
+            if (!$this->maxItems) {
+                // Track misses in non-LRU mode only
+                $this->values[$key] = null;
+            }
        } else {
            $value = $this->storeSerialized ? $this->unfreeze($key, $isHit) : $this->values[$key];
        }
@@ -164,7 +193,9 @@ public function save(CacheItemInterface $item)
        $value = $item["\0*\0value"];
        $expiry = $item["\0*\0expiry"];

-        if (null !== $expiry && $expiry <= microtime(true)) {
+        $now = microtime(true);
+
+        if (null !== $expiry && $expiry <= $now) {
            $this->deleteItem($key);

            return true;
@@ -173,7 +204,23 @@ public function save(CacheItemInterface $item)
            return false;
        }
        if (null === $expiry && 0 < $item["\0*\0defaultLifetime"]) {
-            $expiry = microtime(true) + $item["\0*\0defaultLifetime"];
+            $expiry = $item["\0*\0defaultLifetime"];
+            $expiry = $now + ($expiry > ($this->maxLifetime ?: $expiry) ? $this->maxLifetime : $expiry);
+        } elseif ($this->maxLifetime && (null === $expiry || $expiry > $now + $this->maxLifetime)) {
+            $expiry = $now + $this->maxLifetime;
+        }
+
+        if ($this->maxItems) {
+            unset($this->values[$key]);
+
+            // Iterate items and vacuum expired ones while we are at it
+            foreach ($this->values as $k => $v) {
+                if ($this->expiries[$k] > $now && \count($this->values) < $this->maxItems) {
+                    break;
+                }
+
+                unset($this->values[$k], $this->expiries[$k]);
+            }
        }

        $this->values[$key] = $value;
@@ -210,15 +257,21 @@ public function commit()
    public function clear(string $prefix = '')
    {
        if ('' !== $prefix) {
+            $now = microtime(true);
+
            foreach ($this->values as $key => $value) {
-                if (0 === strpos($key, $prefix)) {
+                if (!isset($this->expiries[$key]) || $this->expiries[$key] <= $now || 0 === strpos($key, $prefix)) {
                    unset($this->values[$key], $this->expiries[$key]);
                }
            }
-        } else {
-            $this->values = $this->expiries = [];
+
+            if ($this->values) {
+                return true;
+            }
        }

+        $this->values = $this->expiries = [];
+
        return true;
    }

@@ -258,8 +311,20 @@ private function generateItems(array $keys, $now, $f)
    {
        foreach ($keys as $i => $key) {
            if (!$isHit = isset($this->expiries[$key]) && ($this->expiries[$key] > $now || !$this->deleteItem($key))) {
-                $this->values[$key] = $value = null;
+                $value = null;
+
+                if (!$this->maxItems) {
+                    // Track misses in non-LRU mode only
+                    $this->values[$key] = null;
+                }
            } else {
+                if ($this->maxItems) {
+                    // Move the item last in the storage
+                    $value = $this->values[$key];
+                    unset($this->values[$key]);
+                    $this->values[$key] = $value;
+                }
+
                $value = $this->storeSerialized ? $this->unfreeze($key, $isHit) : $this->values[$key];
            }
            unset($keys[$i]);
@@ -314,8 +379,12 @@ private function unfreeze(string $key, bool &$isHit)
                $value = false;
            }
            if (false === $value) {
-                $this->values[$key] = $value = null;
+                $value = null;
                $isHit = false;
+
+                if (!$this->maxItems) {
+                    $this->values[$key] = null;
+                }
            }
        }


diff --git a/src/Symfony/Component/Cache/CHANGELOG.md b/src/Symfony/Component/Cache/CHANGELOG.md
@@ -1,6 +1,11 @@
 CHANGELOG
 =========

+5.1.0
+-----
+
+ * added max-items + LRU + max-lifetime capabilities to `ArrayCache`
+
 5.0.0
 -----


diff --git a/src/Symfony/Component/Cache/Tests/Adapter/ArrayAdapterTest.php b/src/Symfony/Component/Cache/Tests/Adapter/ArrayAdapterTest.php
@@ -55,4 +55,36 @@ public function testGetValuesHitAndMiss()
        $this->assertArrayHasKey('bar', $values);
        $this->assertNull($values['bar']);
    }
+
+    public function testMaxLifetime()
+    {
+        $cache = new ArrayAdapter(0, false, 1);
+
+        $item = $cache->getItem('foo');
+        $item->expiresAfter(2);
+        $cache->save($item->set(123));
+
+        $this->assertTrue($cache->hasItem('foo'));
+        sleep(1);
+        $this->assertFalse($cache->hasItem('foo'));
+    }
+
+    public function testMaxItems()
+    {
+        $cache = new ArrayAdapter(0, false, 0, 2);
+
+        $cache->save($cache->getItem('foo'));
+        $cache->save($cache->getItem('bar'));
+        $cache->save($cache->getItem('buz'));
+
+        $this->assertFalse($cache->hasItem('foo'));
+        $this->assertTrue($cache->hasItem('bar'));
+        $this->assertTrue($cache->hasItem('buz'));
+
+        $cache->save($cache->getItem('foo'));
+
+        $this->assertFalse($cache->hasItem('bar'));
+        $this->assertTrue($cache->hasItem('buz'));
+        $this->assertTrue($cache->hasItem('foo'));
+    }
 }