bug #46699 [Cache] Respect $save option in all adapters (jrjohnson)

nicolas-grekas · nicolas-grekas · commit fa4a7a4af835 · 2022-06-19T13:27:28.000+02:00
This PR was merged into the 4.4 branch. Discussion ---------- [Cache] Respect $save option in all adapters | Q | A | ------------- | --- | Branch? | 4.4 | Bug fix? | yes | New feature? | no | Deprecations? | no | Tickets | | License | MIT | Doc PR | I was working with a cache chain which included the array adapter. When we have a cache miss we need to consolidate all of the misses so we can do a single DB query for all values. So first we look in the cache, then and then we can pull the data as a big group, hydrate the results, and then cache them. Because we search for these values a bunch of times in the same request I chained the array and Redis adapter together. Looks like: ``` $hitsAndMisses = array_map( fn(mixed $id) => $this->cache->get($id, function (ItemInterface $item, bool &$save) { $save = false; return false; }), $ids ); $hits = array_filter($hitsAndMisses); //cut: compare arrays to get missed Ids $hydrated = $this->hydrate($missedIds); //very expensive to do individually $missedValues = array_map(fn($obj) => $this->cache->get( $obj->id, function (ItemInterface $item) use ($obj) { return $obj; } ), $hydrated); return array_values([...$hits, ...$missedValues]); ``` Unfortunately neither the `ArrayAdapter` nor the `ChainAdapter` respect the $save reference. I was able to fix the `ArrayAdapter` in this PR, but I'm at a loss for how to do the same for the `ChainAdapter`, but I was able to create a generic failing test. Commits ------- b14aa77 [Cache] Respect $save option in ChainAdapter 5e8de1e [Cache] Respect $save option in ArrayAdapter
diff --git a/src/Symfony/Component/Cache/Adapter/ArrayAdapter.php b/src/Symfony/Component/Cache/Adapter/ArrayAdapter.php
@@ -60,7 +60,10 @@ public function get(string $key, callable $callback, float $beta = null, array &
         // ArrayAdapter works in memory, we don't care about stampede protection
         if (\INF === $beta || !$item->isHit()) {
             $save = true;
-            $this->save($item->set($callback($item, $save)));
+            $item->set($callback($item, $save));
+            if ($save) {
+                $this->save($item);
+            }
         }
 
         return $item->get();
diff --git a/src/Symfony/Component/Cache/Adapter/ChainAdapter.php b/src/Symfony/Component/Cache/Adapter/ChainAdapter.php
@@ -91,9 +91,17 @@ static function ($sourceItem, $item, $sourceMetadata = null) use ($defaultLifeti
      */
     public function get(string $key, callable $callback, float $beta = null, array &$metadata = null)
     {
+        $doSave = true;
+        $callback = static function (CacheItem $item, bool &$save) use ($callback, &$doSave) {
+            $value = $callback($item, $save);
+            $doSave = $save;
+
+            return $value;
+        };
+
         $lastItem = null;
         $i = 0;
-        $wrap = function (CacheItem $item = null) use ($key, $callback, $beta, &$wrap, &$i, &$lastItem, &$metadata) {
+        $wrap = function (CacheItem $item = null, bool &$save = true) use ($key, $callback, $beta, &$wrap, &$i, &$doSave, &$lastItem, &$metadata) {
             $adapter = $this->adapters[$i];
             if (isset($this->adapters[++$i])) {
                 $callback = $wrap;
@@ -107,6 +115,7 @@ public function get(string $key, callable $callback, float $beta = null, array &
             if (null !== $item) {
                 ($this->syncItem)($lastItem = $lastItem ?? $item, $item, $metadata);
             }
+            $save = $doSave;
 
             return $value;
         };
diff --git a/src/Symfony/Component/Cache/Tests/Adapter/AdapterTestCase.php b/src/Symfony/Component/Cache/Tests/Adapter/AdapterTestCase.php
@@ -98,6 +98,31 @@ public function testRecursiveGet()
         $this->assertSame(1, $cache->get('k2', function () { return 2; }));
     }
 
+    public function testDontSaveWhenAskedNotTo()
+    {
+        if (isset($this->skippedTests[__FUNCTION__])) {
+            $this->markTestSkipped($this->skippedTests[__FUNCTION__]);
+        }
+
+        $cache = $this->createCachePool(0, __FUNCTION__);
+
+        $v1 = $cache->get('some-key', function($item, &$save){
+           $save = false;
+           return 1;
+        });
+        $this->assertSame($v1, 1);
+
+        $v2 = $cache->get('some-key', function(){
+            return 2;
+        });
+        $this->assertSame($v2, 2, 'First value was cached and should not have been');
+
+        $v3 = $cache->get('some-key', function(){
+            $this->fail('Value should have come from cache');
+        });
+        $this->assertSame($v3, 2);
+    }
+
     public function testGetMetadata()
     {
         if (isset($this->skippedTests[__FUNCTION__])) {
diff --git a/src/Symfony/Component/Cache/Tests/Adapter/PhpArrayAdapterTest.php b/src/Symfony/Component/Cache/Tests/Adapter/PhpArrayAdapterTest.php
@@ -24,6 +24,7 @@ class PhpArrayAdapterTest extends AdapterTestCase
 {
     protected $skippedTests = [
         'testGet' => 'PhpArrayAdapter is read-only.',
+        'testDontSaveWhenAskedNotTo' => 'PhpArrayAdapter is read-only.',
         'testRecursiveGet' => 'PhpArrayAdapter is read-only.',
         'testBasicUsage' => 'PhpArrayAdapter is read-only.',
         'testBasicUsageWithLongKey' => 'PhpArrayAdapter is read-only.',

Original file line number	Diff line number	Diff line change
`@@ -24,6 +24,7 @@ class PhpArrayAdapterTest extends AdapterTestCase`
`24`	`24`	`{`
`25`	`25`	`protected $skippedTests = [`
`26`	`26`	`'testGet' => 'PhpArrayAdapter is read-only.',`
	`27`	`+ 'testDontSaveWhenAskedNotTo' => 'PhpArrayAdapter is read-only.',`
`27`	`28`	`'testRecursiveGet' => 'PhpArrayAdapter is read-only.',`
`28`	`29`	`'testBasicUsage' => 'PhpArrayAdapter is read-only.',`
`29`	`30`	`'testBasicUsageWithLongKey' => 'PhpArrayAdapter is read-only.',`