bug symfony#61605 [Cache] Fix internal representation of non-static values (nicolas-grekas)

This PR was merged into the 6.4 branch.

Discussion
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[Cache] Fix internal representation of non-static values

| Q             | A
| ------------- | ---
| Branch?       | 6.4
| Bug fix?      | yes
| New feature?  | no
| Deprecations? | no
| Issues        | -
| License       | MIT

I'm working on a PR to allow exporting named closures, and the way we use closures in PhpArrayAdapter and PhpFilesAdapter gets into my way.

Instead of relying on `instanceof \Closure` checks, this PR adds an internal marker interface. This makes the logic specific to the component, enabling having closures as regular cached values.

The new logic is tested since adapters are.

Commits
-------

a5823af [Cache] Fix internal representation of non-static values

Author: nicolas-grekas

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

@@ -17,6 +17,7 @@
 use Symfony\Component\Cache\Exception\InvalidArgumentException;
 use Symfony\Component\Cache\PruneableInterface;
 use Symfony\Component\Cache\ResettableInterface;
+use Symfony\Component\Cache\Traits\CachedValueInterface;
 use Symfony\Component\Cache\Traits\ContractsTrait;
 use Symfony\Component\Cache\Traits\ProxyTrait;
 use Symfony\Component\VarExporter\VarExporter;
@@ -96,16 +97,15 @@ public function get(string $key, callable $callback, ?float $beta = null, ?array
         if ('N;' === $value) {
             return null;
         }
+        if (!$value instanceof CachedValueInterface) {
+            return $value;
+        }
         try {
-            if ($value instanceof \Closure) {
-                return $value();
-            }
+            return $value->getValue();
         } catch (\Throwable) {
             unset($this->keys[$key]);
             goto get_from_pool;
         }
-
-        return $value;
     }
 
     public function getItem(mixed $key): CacheItem
@@ -125,9 +125,9 @@ public function getItem(mixed $key): CacheItem
 
         if ('N;' === $value) {
             $value = null;
-        } elseif ($value instanceof \Closure) {
+        } elseif ($value instanceof CachedValueInterface) {
             try {
-                $value = $value();
+                $value = $value->getValue();
             } catch (\Throwable) {
                 $value = null;
                 $isHit = false;
@@ -306,8 +306,7 @@ public function warmUp(array $values): array
             }
 
             if (!$isStaticValue) {
-                $value = str_replace("\n", "\n    ", $value);
-                $value = "static function () {\n    return {$value};\n}";
+                $value = 'new class() implements \\'.CachedValueInterface::class." { public function getValue(): mixed { return {$value}; } }";
             }
             $hash = hash('xxh128', $value);
 
@@ -368,9 +367,9 @@ private function generateItems(array $keys): \Generator
 
                 if ('N;' === $value) {
                     yield $key => $f($key, null, true);
-                } elseif ($value instanceof \Closure) {
+                } elseif ($value instanceof CachedValueInterface) {
                     try {
-                        yield $key => $f($key, $value(), true);
+                        yield $key => $f($key, $value->getValue(), true);
                     } catch (\Throwable) {
                         yield $key => $f($key, null, false);
                     }

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

@@ -14,6 +14,7 @@
 use Symfony\Component\Cache\Exception\CacheException;
 use Symfony\Component\Cache\Exception\InvalidArgumentException;
 use Symfony\Component\Cache\PruneableInterface;
+use Symfony\Component\Cache\Traits\CachedValueInterface;
 use Symfony\Component\Cache\Traits\FilesystemCommonTrait;
 use Symfony\Component\VarExporter\VarExporter;
 
@@ -114,8 +115,10 @@ protected function doFetch(array $ids): iterable
                 $values[$id] = null;
             } elseif (!\is_object($value)) {
                 $values[$id] = $value;
+            } elseif ($value instanceof CachedValueInterface) {
+                $values[$id] = $value->getValue();
             } elseif (!$value instanceof LazyValue) {
-                $values[$id] = $value();
+                $values[$id] = $value;
             } elseif (false === $values[$id] = include $value->file) {
                 unset($values[$id], $this->values[$id]);
                 $missingIds[] = $id;
@@ -152,7 +155,7 @@ protected function doFetch(array $ids): iterable
                     if ($now >= $expiresAt) {
                         unset($this->values[$id], $missingIds[$k], self::$valuesCache[$file]);
                     }
-                } catch (\ErrorException $e) {
+                } catch (\ErrorException) {
                     unset($missingIds[$k]);
                 }
             }
@@ -236,7 +239,7 @@ protected function doSave(array $values, int $lifetime): array|bool
             if ($isStaticValue) {
                 $value = "return [{$expiry}, {$value}];";
             } elseif ($this->appendOnly) {
-                $value = "return [{$expiry}, static fn () => {$value}];";
+                $value = "return [{$expiry}, new class() implements \\".CachedValueInterface::class." { public function getValue(): mixed { return {$value}; } }];";
             } else {
                 // We cannot use a closure here because of https://bugs.php.net/76982
                 $value = str_replace('\Symfony\Component\VarExporter\Internal\\', '', $value);

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

@@ -0,0 +1,20 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Cache\Traits;
+
+/**
+ * @internal
+ */
+interface CachedValueInterface
+{
+    public function getValue(): mixed;
+}