[Cache] work aroung PHP memory leak

nicolas-grekas · nicolas-grekas · commit bb191cfb7fb2 · 2019-06-28T10:19:15.000+02:00
diff --git a/src/Symfony/Component/Cache/Traits/PhpFilesTrait.php b/src/Symfony/Component/Cache/Traits/PhpFilesTrait.php
@@ -50,12 +50,15 @@ public function prune()
     {
         $time = time();
         $pruned = true;
+        $getExpiry = true;
 
         set_error_handler($this->includeHandler);
         try {
             foreach (new \RecursiveIteratorIterator(new \RecursiveDirectoryIterator($this->directory, \FilesystemIterator::SKIP_DOTS), \RecursiveIteratorIterator::LEAVES_ONLY) as $file) {
                 try {
-                    list($expiresAt) = include $file;
+                    if (\is_array($expiresAt = include $file)) {
+                        $expiresAt = $expiresAt[0];
+                    }
                 } catch (\ErrorException $e) {
                     $expiresAt = $time;
                 }
@@ -87,13 +90,21 @@ protected function doFetch(array $ids)
         $values = [];
 
         begin:
+        $getExpiry = false;
+
         foreach ($ids as $id) {
             if (null === $value = $this->values[$id] ?? null) {
                 $missingIds[] = $id;
             } elseif ('N;' === $value) {
                 $values[$id] = null;
-            } elseif ($value instanceof \Closure) {
-                $values[$id] = $value();
+            } elseif (\is_object($value)) {
+                if (!$value instanceof LazyValue) {
+                    // calling a Closure is for @deprecated BC and should be removed in Symfony 5.0
+                    $values[$id] = $value();
+                } elseif (false === $values[$id] = include $value->file) {
+                    unset($values[$id], $this->values[$id]);
+                    $missingIds[] = $id;
+                }
             } else {
                 $values[$id] = $value;
             }
@@ -108,10 +119,18 @@ protected function doFetch(array $ids)
 
         set_error_handler($this->includeHandler);
         try {
+            $getExpiry = true;
+
             foreach ($missingIds as $k => $id) {
                 try {
                     $file = $this->files[$id] ?? $this->files[$id] = $this->getFile($id);
-                    list($expiresAt, $this->values[$id]) = include $file;
+
+                    if (\is_array($expiresAt = include $file)) {
+                        [$expiresAt, $this->values[$id]] = $expiresAt;
+                    } elseif ($now < $expiresAt) {
+                        $this->values[$id] = new LazyValue($file);
+                    }
+
                     if ($now >= $expiresAt) {
                         unset($this->values[$id], $missingIds[$k]);
                     }
@@ -140,7 +159,13 @@ protected function doHave($id)
         set_error_handler($this->includeHandler);
         try {
             $file = $this->files[$id] ?? $this->files[$id] = $this->getFile($id);
-            list($expiresAt, $value) = include $file;
+            $getExpiry = true;
+
+            if (\is_array($expiresAt = include $file)) {
+                [$expiresAt, $value] = $expiresAt;
+            } elseif ($this->appendOnly) {
+                $value = new LazyValue($file);
+            }
         } catch (\ErrorException $e) {
             return false;
         } finally {
@@ -189,13 +214,16 @@ protected function doSave(array $values, $lifetime)
             }
 
             if (!$isStaticValue) {
-                $value = str_replace("\n", "\n    ", $value);
-                $value = "static function () {\n\n    return {$value};\n\n}";
+                // We cannot use a closure here because of https://bugs.php.net/76982
+                $value = str_replace('\Symfony\Component\VarExporter\Internal\\', '', $value);
+                $value = "<?php\n\nnamespace Symfony\Component\VarExporter\Internal;\n\nreturn \$getExpiry ? {$expiry} : {$value};\n";
+            } else {
+                $value = "<?php return [{$expiry}, {$value}];\n";
             }
 
             $file = $this->files[$key] = $this->getFile($key, true);
             // Since OPcache only compiles files older than the script execution start, set the file's mtime in the past
-            $ok = $this->write($file, "<?php return [{$expiry}, {$value}];\n", self::$startTime - 10) && $ok;
+            $ok = $this->write($file, $value, self::$startTime - 10) && $ok;
 
             if ($allowCompile) {
                 @opcache_invalidate($file, true);
@@ -241,3 +269,16 @@ protected function doUnlink($file)
         return @unlink($file);
     }
 }
+
+/**
+ * @internal
+ */
+class LazyValue
+{
+    public $file;
+
+    public function __construct($file)
+    {
+        $this->file = $file;
+    }
+}
