symfony · nicolas-grekas · Apr 26, 2016
diff --git a/src/Symfony/Component/Cache/Adapter/AbstractAdapter.php b/src/Symfony/Component/Cache/Adapter/AbstractAdapter.php
@@ -47,17 +47,22 @@ function ($key, $value, $isHit) use ($defaultLifetime) {
         );
         $this->mergeByLifetime = \Closure::bind(
             function ($deferred, $namespace, &$expiredIds) {
-                $byLifetime = array();
+                $byLifetime = array('value' => array(), 'tags' => array());
                 $now = time();
                 $expiredIds = array();
 
                 foreach ($deferred as $key => $item) {
+                    $id = $namespace.$key;
+
                     if (null === $item->expiry) {
-                        $byLifetime[0][$namespace.$key] = $item->value;
+                        $byLifetime['value'][0][$id] = $item->value;
+                        $byLifetime['tags'][0][$id] = $item->tags;
                     } elseif ($item->expiry > $now) {
-                        $byLifetime[$item->expiry - $now][$namespace.$key] = $item->value;
+                        $byLifetime['value'][$item->expiry - $now][$id] = $item->value;
+                        $byLifetime['tags'][$item->expiry - $now][$id] = $item->tags;
                     } else {
-                        $expiredIds[] = $namespace.$key;
+                        $expiredIds[] = $id;
+                        continue;
                     }
                 }
 
@@ -313,9 +318,13 @@ public function commit()
         if ($expiredIds) {
             $this->doDelete($expiredIds);
         }
-        foreach ($byLifetime as $lifetime => $values) {
+        foreach ($byLifetime['value'] as $lifetime => $values) {
             try {
-                $e = $this->doSave($values, $lifetime);
+                if ($this instanceof AbstractTagsInvalidatingAdapter) {
+                    $e = $this->doSaveWithTags($values, $lifetime, $byLifetime['tags'][$lifetime]);
+                } else {
+                    $e = $this->doSave($values, $lifetime);
+                }
             } catch (\Exception $e) {
             }
             if (true === $e || array() === $e) {
@@ -339,8 +348,12 @@ public function commit()
         foreach ($retry as $lifetime => $ids) {
             foreach ($ids as $id) {
                 try {
-                    $v = $byLifetime[$lifetime][$id];
-                    $e = $this->doSave(array($id => $v), $lifetime);
+                    $v = $byLifetime['value'][$lifetime][$id];
+                    if ($this instanceof AbstractTagsInvalidatingAdapter) {
+                        $e = $this->doSaveWithTags(array($id => $v), $lifetime, array($id => $byLifetime['tags'][$lifetime][$id]));
+                    } else {
+                        $e = $this->doSave(array($id => $v), $lifetime);
+                    }
                 } catch (\Exception $e) {
                 }
                 if (true === $e || array() === $e) {

diff --git a/src/Symfony/Component/Cache/Adapter/AbstractTagsInvalidatingAdapter.php b/src/Symfony/Component/Cache/Adapter/AbstractTagsInvalidatingAdapter.php
@@ -0,0 +1,37 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Cache\Adapter;
+
+/**
+ * @author Nicolas Grekas <p@tchwork.com>
+ */
+abstract class AbstractTagsInvalidatingAdapter extends AbstractAdapter implements TagsInvalidatingAdapterInterface
+{
+    /**
+     * Persists several cache items immediately.
+     *
+     * @param array $values   The values to cache, indexed by their cache identifier.
+     * @param int   $lifetime The lifetime of the cached values, 0 for persisting until manual cleaning.
+     * @param array $tags     The tags corresponding to each value identifiers.
+     *
+     * @return array|bool The identifiers that failed to be cached or a boolean stating if caching succeeded or not.
+     */
+    abstract protected function doSaveWithTags(array $values, $lifetime, array $tags);
+
+    /**
+     * @internal
+     */
+    protected function doSave(array $values, $lifetime)
+    {
+        throw new \BadMethodCallException('Use doSaveWithTags() instead.');
+    }
+}
diff --git a/src/Symfony/Component/Cache/Adapter/FilesystemAdapter.php b/src/Symfony/Component/Cache/Adapter/FilesystemAdapter.php
@@ -11,10 +11,12 @@
 
 namespace Symfony\Component\Cache\Adapter;
 
+use Symfony\Component\Cache\CacheItem;
+
 /**
  * @author Nicolas Grekas <p@tchwork.com>
  */
-class FilesystemAdapter extends AbstractAdapter
+class FilesystemAdapter extends AbstractTagsInvalidatingAdapter
 {
     use FilesystemAdapterTrait;
 
@@ -24,6 +26,20 @@ public function __construct($namespace = '', $defaultLifetime = 0, $directory =
         $this->init($namespace, $directory);
     }
 
+    /**
+     * {@inheritdoc}
+     */
+    public function invalidateTags($tags)
+    {
+        $ok = true;
+
+        foreach (CacheItem::normalizeTags($tags) as $tag) {
+            $ok = $this->doInvalidateTag($tag) && $ok;
+        }
+
+        return $ok;
+    }
+
     /**
      * {@inheritdoc}
      */
@@ -68,15 +84,125 @@ protected function doHave($id)
     /**
      * {@inheritdoc}
      */
-    protected function doSave(array $values, $lifetime)
+    protected function doSaveWithTags(array $values, $lifetime, array $tags)
     {
         $ok = true;
         $expiresAt = $lifetime ? time() + $lifetime : PHP_INT_MAX;
+        $newTags = $oldTags = array();
 
         foreach ($values as $id => $value) {
+            $newIdTags = $tags[$id];
            $file = $this->getFile($id, true);
+            $tagFile = $this->getFile($id.':tag', $newIdTags);
+            $hasFile = file_exists($file);
+
+            if ($hadTags = file_exists($tagFile)) {
+                foreach (file($tagFile, FILE_IGNORE_NEW_LINES) as $tag) {
+                    if (isset($newIdTags[$tag = rawurldecode($tag)])) {
+                        if ($hasFile) {
+                            unset($newIdTags[$tag]);
+                        }
+                    } else {
+                        $oldTags[] = $tag;
+                    }
+                }
+                if ($oldTags) {
+                    $this->removeTags($id, $oldTags);
+                    $oldTags = array();
+                }
+            }
+            foreach ($newIdTags as $tag) {
+                $newTags[$tag][] = $id;
+            }
+
             $ok = $this->write($this->getFile($id, true), $expiresAt."\n".rawurlencode($id)."\n".serialize($value), $expiresAt) && $ok;
+
+            if ($tags[$id]) {
+                $ok = $this->write($tagFile, implode("\n", array_map('rawurlencode', $tags[$id]))."\n") && $ok;
+            } elseif ($hadTags) {
+                @unlink($tagFile);
+            }
+        }
+        if ($newTags) {
+            $ok = $this->doTag($newTags) && $ok;
+        }
+
+        return $ok;
+    }
+
+    private function doTag(array $tags)
+    {
+        $ok = true;
+        $linkedTags = array();
+
+        foreach ($tags as $tag => $ids) {
+            $file = $this->getFile($tag, true);
+            $linkedTags[$tag] = file_exists($file) ?: null;
+            $h = fopen($file, 'ab');
+
+            foreach ($ids as $id) {
+                $ok = fwrite($h, rawurlencode($id)."\n") && $ok;
+            }
+            fclose($h);
+
+            while (!isset($linkedTags[$tag]) && 0 < $r = strrpos($tag, '/')) {
+                $linkedTags[$tag] = true;
+                $parent = substr($tag, 0, $r);
+                $file = $this->getFile($parent, true);
+                $linkedTags[$parent] = file_exists($file) ?: null;
+                $ok = file_put_contents($file, rawurlencode($tag)."\n", FILE_APPEND) && $ok;
+                $tag = $parent;
+            }
+        }
+
+        return $ok;
+    }
+
+    private function doInvalidateTag($tag)
+    {
+        if (!$h = @fopen($this->getFile($tag), 'r+b')) {
+            return true;
+        }
+        $ok = true;
+        $count = 0;
+
+        while (false !== $id = fgets($h)) {
+            if ('!' === $id[0]) {
+                continue;
+            }
+            $id = rawurldecode(substr($id, 0, -1));
+
+            if ('/' === $id[0]) {
+                $ok = $this->doInvalidateTag($id) && $ok;
+            } elseif (file_exists($file = $this->getFile($id))) {
+                $count += $unlink = @unlink($file);
+                $ok = ($unlink || !file_exists($file)) && $ok;
+            }
         }
 
+        ftruncate($h, 0);
+        fclose($h);
+        CacheItem::log($this->logger, 'Invalidating {count} items tagged as "{tag}"', array('tag' => $tag, 'count' => $count));
+
         return $ok;
     }
+
+    private function removeTags($id, $tags)
+    {
+        $idLine = rawurlencode($id)."\n";
+        $idSeek = -strlen($idLine);
+
+        foreach ($tags as $tag) {
+            if (!$h = @fopen($this->getFile($tag), 'r+b')) {
+                continue;
+            }
+            while (false !== $line = fgets($h)) {
+                if ($line === $idLine) {
+                    fseek($h, $idSeek, SEEK_CUR);
+                    fwrite($h, '!');
+                }
+            }
+            fclose($h);
+        }
+    }
 }