query cache

Author: nekufa

README.md

@@ -172,6 +172,20 @@ $mapper->cache = $cache;
 $mapper->getSpace('_vspace'); // no new requests are made
 ```
 
+## Query Cache
+If you don't want to perform select queries you can inject cache interface to space instance/\
+For example, we use apcu adapter from `symfony/cache` package.
+```php
+use Symfony\Component\Cache\Adapter\ArrayAdapter;
+
+$mapper = new Mapper(Client::fromDefaults());
+$mapper->getSpace('_vspace')->cache = new ArrayAdapter(); // feel free to set default ttl
+
+$mapper->find('_vspace'); // query is executed
+$mapper->find('_vspace'); // results are fetched from cache
+$mapper->find('_vspace'); // results are fetched from cache
+```
+
 ## Changes registration
 In some cases you want to get all changes that were made during current session.\
 By default spy configuration is set to false, this improves performance a bit.

src/Space.php

@@ -5,6 +5,7 @@
 namespace Tarantool\Mapper;
 
 use Exception;
+use Psr\Cache\CacheItemPoolInterface;
 use ReflectionClass;
 use ReflectionMethod;
 use Tarantool\Client\Exception\RequestFailed;
@@ -17,6 +18,8 @@
 
 class Space
 {
+    public ?CacheItemPoolInterface $cache = null;
+
     private readonly int $id;
     private readonly string $name;
 
@@ -163,8 +166,22 @@ public function find(Criteria|array|null $criteria = null, ?int $limit = null):
             $criteria = $criteria->andLimit($limit);
         }
 
+        $item = null;
+        if ($this->cache) {
+            $item = $this->cache->getItem(md5(serialize($criteria)));
+            if ($item->isHit()) {
+                return $item->get();
+            }
+        }
+
         $tuples = $this->mapper->client->getSpaceById($this->id)->select($criteria);
-        return array_map($this->getInstance(...), $tuples);
+        $result = array_map($this->getInstance(...), $tuples);
+        if ($item) {
+            $item->set($result);
+            $this->cache->save($item);
+        }
+
+        return $result;
     }
 
     public function findOne(Criteria|array|null $criteria = null)

tests/MapperTest.php

@@ -40,23 +40,31 @@ public function testCache()
         $mapper = $this->createMapper(dropUserSpaces: false);
         $cache = new ArrayAdapter();
         $mapper->cache = $cache;
-        $this->assertCount(0, $cache->getvalues());
         $mapper->dropUserSpaces();
         $mapper->find('_vspace');
 
-        $this->assertNotCount(0, $cache->getvalues());
+        $this->assertNotCount(0, $cache->getValues());
 
         $freshCounter = count($this->middleware->data);
-
         $mapper = $this->createMapper(dropUserSpaces: false);
         $mapper->cache = $cache;
         $mapper->dropUserSpaces();
         $mapper->find('_vspace');
 
-        // 4 requests:
-        // - schema id 0 space + index
-        // - schema id N space + index
-        $this->assertCount($freshCounter - 4, $this->middleware->data);
+        $this->assertLessThan($freshCounter, count($this->middleware->data));
+
+        $cache = new ArrayAdapter();
+        $mapper->getSpace('_vspace')->cache = $cache;
+
+        $mapper->find('_vspace');
+        $this->assertCount(1, $cache->getValues());
+        $queries = count($this->middleware->data);
+
+        $mapper->find('_vspace');
+        $mapper->find('_vspace');
+        $mapper->find('_vspace');
+        $this->assertCount(1, $cache->getValues());
+        $this->assertCount($queries, $this->middleware->data);
     }
 
     public function testDifferentIndexPartConfiguration()