Uses identityMap from Data

Author: alganet

src/Mapper.php

@@ -44,6 +44,13 @@ public function __construct(PDO|Db $db, EntityFactory $entityFactory = new Entit
 
     public function fetch(Collection $collection, mixed $extra = null): mixed
     {
+        if ($extra === null) {
+            $cached = $this->findInIdentityMap($collection);
+            if ($cached !== null) {
+                return $cached;
+            }
+        }
+
         $hydrated = $this->fetchHydrated($collection, $this->createStatement($collection, $extra));
 
         return $hydrated ? $this->parseHydrated($hydrated) : false;
@@ -97,7 +104,7 @@ public function flush(): void
         $conn->beginTransaction();
 
         try {
-            foreach ($this->changed as $entity) {
+            foreach ($this->pending as $entity) {
                 $this->flushSingle($entity);
             }
         } catch (Throwable $e) {
@@ -133,15 +140,20 @@ private function getRelatedEntity(object $object, string $remoteField): object|n
 
     private function flushSingle(object $entity): void
     {
-        $coll    = $this->tracked[$entity];
-        $cols    = $this->extractColumns($entity, $coll);
-
-        if ($this->removed->offsetExists($entity)) {
-            $this->rawDelete($cols, $coll, $entity);
-        } elseif ($this->new->offsetExists($entity)) {
-            $this->rawInsert($cols, $coll, $entity);
+        $coll = $this->tracked[$entity];
+        $cols = $this->extractColumns($entity, $coll);
+        $op   = $this->pending[$entity];
+
+        match ($op) {
+            'delete' => $this->rawDelete($cols, $coll, $entity),
+            'insert' => $this->rawInsert($cols, $coll, $entity),
+            default  => $this->rawUpdate($cols, $coll),
+        };
+
+        if ($op === 'delete') {
+            $this->evictFromIdentityMap($entity, $coll);
         } else {
-            $this->rawUpdate($cols, $coll);
+            $this->registerInIdentityMap($entity, $coll);
         }
     }
 
@@ -489,6 +501,12 @@ private function hasComposition(string $entity, string|null $next, string|null $
     private function parseHydrated(SplObjectStorage $hydrated): object
     {
         $this->tracked->addAll($hydrated);
+
+        // Register all hydrated entities in the PK-indexed identity map
+        foreach ($hydrated as $entity) {
+            $this->registerInIdentityMap($entity, $hydrated[$entity]);
+        }
+
         $hydrated->rewind();
 
         return $hydrated->current();

tests/MapperTest.php

@@ -1242,6 +1242,116 @@ public function testFilteredPersistInsertsOnlyFilteredColumns(): void
         $this->assertNull($row['text'], 'Non-filtered columns should not be inserted');
     }
 
+    /** Identity Map: fetch() short-circuit */
+    public function testFetchReturnsSameInstanceOnRepeatedPkLookup(): void
+    {
+        $first = $this->mapper->post(5)->fetch();
+        $second = $this->mapper->post(5)->fetch();
+
+        $this->assertSame($first, $second);
+    }
+
+    public function testFetchWithExtraBypassesIdentityMap(): void
+    {
+        $first = $this->mapper->post(5)->fetch();
+        $extra = new Sql();
+        $extra->orderBy('post.id');
+        $second = $this->mapper->post(5)->fetch($extra);
+
+        $this->assertNotSame($first, $second);
+        $this->assertEquals($first->id, $second->id);
+    }
+
+    public function testIdentityMapCountIncreasesOnFetch(): void
+    {
+        $this->assertSame(0, $this->mapper->identityMapCount());
+
+        $this->mapper->author(1)->fetch();
+
+        $this->assertGreaterThan(0, $this->mapper->identityMapCount());
+    }
+
+    public function testClearIdentityMapForcesFreshFetch(): void
+    {
+        $first = $this->mapper->post(5)->fetch();
+        $this->mapper->clearIdentityMap();
+        $second = $this->mapper->post(5)->fetch();
+
+        $this->assertNotSame($first, $second);
+        $this->assertEquals($first->id, $second->id);
+    }
+
+    /** Identity Map: flushSingle() insert/update/delete */
+    public function testInsertedEntityIsRetrievableFromIdentityMap(): void
+    {
+        $entity = new stdClass();
+        $entity->id = null;
+        $entity->title = 'New Post';
+        $entity->text = 'New Text';
+        $entity->author_id = 1;
+
+        $this->mapper->post->persist($entity);
+        $this->mapper->flush();
+
+        // The entity should now have an auto-assigned id and be cached
+        $this->assertNotNull($entity->id);
+
+        $fetched = $this->mapper->post($entity->id)->fetch();
+        $this->assertSame($entity, $fetched);
+    }
+
+    public function testUpdatedEntityKeepsReturningUpdatedInstance(): void
+    {
+        $entity = $this->mapper->post(5)->fetch();
+        $entity->title = 'Updated Title';
+
+        $this->mapper->post->persist($entity);
+        $this->mapper->flush();
+
+        $fetched = $this->mapper->post(5)->fetch();
+        $this->assertSame($entity, $fetched);
+        $this->assertSame('Updated Title', $fetched->title);
+    }
+
+    public function testDeletedEntityIsEvictedFromIdentityMap(): void
+    {
+        $entity = $this->mapper->post(5)->fetch();
+        $this->assertSame($entity, $this->mapper->post(5)->fetch());
+
+        $this->mapper->post->remove($entity);
+        $this->mapper->flush();
+
+        // After delete, fetch should hit DB (and return false since the row is gone)
+        $result = $this->mapper->post(5)->fetch();
+        $this->assertFalse($result);
+    }
+
+    /** Identity Map: parseHydrated() registers related entities */
+    public function testRelatedEntityFromJoinReturnsSameInstanceOnDirectFetch(): void
+    {
+        // Fetch a comment with its related post via join
+        $comment = $this->mapper->comment(7)->post->fetch();
+
+        // The related post entity should have been registered in the identity map
+        $post = $this->mapper->post(5)->fetch();
+        $this->assertSame($comment->post_id, $post->id);
+
+        // They should be the same object instance since parseHydrated()
+        // registers all entities (including nested ones) in the identity map
+        $this->assertSame($post, $this->mapper->post($post->id)->fetch());
+    }
+
+    public function testNestedRelatedEntitiesAllRegisteredInIdentityMap(): void
+    {
+        $this->mapper->comment(7)->post->author->fetch();
+
+        $postFromMap = $this->mapper->post(5)->fetch();
+        $authorFromMap = $this->mapper->author(1)->fetch();
+
+        $this->assertSame($postFromMap, $this->mapper->post(5)->fetch());
+        $this->assertSame($authorFromMap, $this->mapper->author(1)->fetch());
+    }
+
     private function query(string $sql): PDOStatement
     {
         $stmt = $this->conn->query($sql);