bug #34896 [Cache] fix memory leak when using PhpFilesAdapter (nicolas-grekas)

This PR was merged into the 4.3 branch.

Discussion
----------

[Cache] fix memory leak when using PhpFilesAdapter

| Q             | A
| ------------- | ---
| Branch?       | 4.3
| Bug fix?      | yes
| New feature?  | no
| Deprecations? | no
| Tickets       | Fix #34687
| License       | MIT
| Doc PR        | -

Similar to #34839 but for `PhpFilesAdapter`, as the "appendOnly" mode is a v4-only feature.

Commits
-------

0b46226648 [Cache] fix memory leak when using PhpFilesAdapter

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

@@ -0,0 +1,31 @@
+<?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\Tests\Adapter;
+
+use Psr\Cache\CacheItemPoolInterface;
+use Symfony\Component\Cache\Adapter\PhpFilesAdapter;
+
+/**
+ * @group time-sensitive
+ */
+class PhpFilesAdapterAppendOnlyTest extends PhpFilesAdapterTest
+{
+    protected $skippedTests = [
+        'testDefaultLifeTime' => 'PhpFilesAdapter does not allow configuring a default lifetime.',
+        'testExpiration' => 'PhpFilesAdapter in append-only mode does not expiration.',
+    ];
+
+    public function createCachePool(): CacheItemPoolInterface
+    {
+        return new PhpFilesAdapter('sf-cache', 0, null, true);
+    }
+}

src/Symfony/Component/Cache/Traits/FilesystemCommonTrait.php

@@ -26,7 +26,7 @@ trait FilesystemCommonTrait
     private function init($namespace, $directory)
     {
         if (!isset($directory[0])) {
-            $directory = sys_get_temp_dir().'/symfony-cache';
+            $directory = sys_get_temp_dir().\DIRECTORY_SEPARATOR.'symfony-cache';
         } else {
             $directory = realpath($directory) ?: $directory;
         }
@@ -55,8 +55,8 @@ trait FilesystemCommonTrait
     {
         $ok = true;
 
-        foreach (new \RecursiveIteratorIterator(new \RecursiveDirectoryIterator($this->directory, \FilesystemIterator::SKIP_DOTS)) as $file) {
+        foreach (new \RecursiveIteratorIterator(new \RecursiveDirectoryIterator($this->directory, \FilesystemIterator::SKIP_DOTS | \FilesystemIterator::CURRENT_AS_PATHNAME), \RecursiveIteratorIterator::LEAVES_ONLY) as $file) {
-            $ok = ($file->isDir() || $this->doUnlink($file) || !file_exists($file)) && $ok;
+            $ok = ($this->doUnlink($file) || !file_exists($file)) && $ok;
         }
 
         return $ok;

src/Symfony/Component/Cache/Traits/PhpFilesTrait.php

@@ -35,12 +35,13 @@ trait PhpFilesTrait
     private $files = [];
 
     private static $startTime;
+    private static $valuesCache = [];
 
     public static function isSupported()
     {
         self::$startTime = self::$startTime ?? $_SERVER['REQUEST_TIME'] ?? time();
 
-        return \function_exists('opcache_invalidate') && ('cli' !== \PHP_SAPI || filter_var(ini_get('opcache.enable_cli'), FILTER_VALIDATE_BOOLEAN)) && filter_var(ini_get('opcache.enable'), FILTER_VALIDATE_BOOLEAN);
+        return \function_exists('opcache_invalidate') && filter_var(ini_get('opcache.enable'), FILTER_VALIDATE_BOOLEAN) && (!\in_array(\PHP_SAPI, ['cli', 'phpdbg'], true) || filter_var(ini_get('opcache.enable_cli'), FILTER_VALIDATE_BOOLEAN));
     }
 
     /**
@@ -54,7 +55,7 @@ trait PhpFilesTrait
 
         set_error_handler($this->includeHandler);
         try {
-            foreach (new \RecursiveIteratorIterator(new \RecursiveDirectoryIterator($this->directory, \FilesystemIterator::SKIP_DOTS), \RecursiveIteratorIterator::LEAVES_ONLY) as $file) {
+            foreach (new \RecursiveIteratorIterator(new \RecursiveDirectoryIterator($this->directory, \FilesystemIterator::SKIP_DOTS | \FilesystemIterator::CURRENT_AS_PATHNAME), \RecursiveIteratorIterator::LEAVES_ONLY) as $file) {
                 try {
                     if (\is_array($expiresAt = include $file)) {
                         $expiresAt = $expiresAt[0];
@@ -100,7 +101,6 @@ trait PhpFilesTrait
             } elseif (!\is_object($value)) {
                 $values[$id] = $value;
             } elseif (!$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]);
@@ -123,14 +123,20 @@ trait PhpFilesTrait
                 try {
                     $file = $this->files[$id] ?? $this->files[$id] = $this->getFile($id);
 
-                    if (\is_array($expiresAt = include $file)) {
+                    if (isset(self::$valuesCache[$file])) {
+                        [$expiresAt, $this->values[$id]] = self::$valuesCache[$file];
+                    } elseif (\is_array($expiresAt = include $file)) {
+                        if ($this->appendOnly) {
+                            self::$valuesCache[$file] = $expiresAt;
+                        }
+
                         [$expiresAt, $this->values[$id]] = $expiresAt;
                     } elseif ($now < $expiresAt) {
                         $this->values[$id] = new LazyValue($file);
                     }
 
                     if ($now >= $expiresAt) {
-                        unset($this->values[$id], $missingIds[$k]);
+                        unset($this->values[$id], $missingIds[$k], self::$valuesCache[$file]);
                     }
                 } catch (\ErrorException $e) {
                     unset($missingIds[$k]);
@@ -159,7 +165,13 @@ trait PhpFilesTrait
             $file = $this->files[$id] ?? $this->files[$id] = $this->getFile($id);
             $getExpiry = true;
 
-            if (\is_array($expiresAt = include $file)) {
+            if (isset(self::$valuesCache[$file])) {
+                [$expiresAt, $value] = self::$valuesCache[$file];
+            } elseif (\is_array($expiresAt = include $file)) {
+                if ($this->appendOnly) {
+                    self::$valuesCache[$file] = $expiresAt;
+                }
+
                 [$expiresAt, $value] = $expiresAt;
             } elseif ($this->appendOnly) {
                 $value = new LazyValue($file);
@@ -211,12 +223,14 @@ trait PhpFilesTrait
                 $value = var_export($value, true);
             }
 
-            if (!$isStaticValue) {
+            if ($isStaticValue) {
+                $value = "<?php return [{$expiry}, {$value}];\n";
+            } elseif ($this->appendOnly) {
+                $value = "<?php return [{$expiry}, static function () { return {$value}; }];\n";
+            } else {
                 // 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);
@@ -227,6 +241,7 @@ trait PhpFilesTrait
                 @opcache_invalidate($file, true);
                 @opcache_compile_file($file);
             }
+            unset(self::$valuesCache[$file]);
         }
 
         if (!$ok && !is_writable($this->directory)) {
@@ -260,6 +275,8 @@ trait PhpFilesTrait
 
     protected function doUnlink($file)
     {
+        unset(self::$valuesCache[$file]);
+
         if (self::isSupported()) {
             @opcache_invalidate($file, true);
         }