Fixed Issue #17295 : Search REST API returns wrong total_count

lib/internal/Magento/Framework/Search/Adapter/Mysql/Adapter.php

@@ -49,6 +49,16 @@ class Adapter implements AdapterInterface
      */
     private $temporaryStorageFactory;
 
+    /**
+     * Query Select Parts to be skipped when prepare query for count
+     *
+     * @var array
+     */
+    protected $countSqlSkipParts = [
+        \Magento\Framework\DB\Select::LIMIT_COUNT => true,
+        \Magento\Framework\DB\Select::LIMIT_OFFSET => true,
+    ];
+
     /**
      * @param Mapper $mapper
      * @param ResponseFactory $responseFactory
@@ -86,6 +96,7 @@ public function query(RequestInterface $request)
         $response = [
             'documents' => $documents,
             'aggregations' => $aggregations,
+            'size' => $this->getSize($query)
         ];
         return $this->responseFactory->create($response);
     }
@@ -114,4 +125,35 @@ private function getConnection()
     {
         return $this->resource->getConnection();
     }
+
+    /**
+     * Get rows size
+     *
+     * @return int
+     */
+    public function getSize($query)
+    {
+        $sql = $this->getSelectCountSql($query);
+        $parentSelect = $this->getConnection()->select();
+        $parentSelect->from(['core_select' => $sql]);
+        $parentSelect->reset(\Magento\Framework\DB\Select::COLUMNS);
+        $parentSelect->columns('COUNT(*)');
+        $totalRecords = $this->getConnection()->fetchOne($parentSelect);
+        return (int)$totalRecords;
+    }
+
+    /**
+     * Reset limit and offset
+     *
+     * @return Select
+     */
+    protected function getSelectCountSql($query)
+    {
+        foreach ($this->countSqlSkipParts as $part => $toSkip) {
+            if ($toSkip) {
+                $query->reset($part);
+            }
+        }
+        return $query;
+    }
 }

lib/internal/Magento/Framework/Search/Adapter/Mysql/ResponseFactory.php

@@ -68,7 +68,8 @@ public function create($rawResponse)
             \Magento\Framework\Search\Response\QueryResponse::class,
             [
                 'documents' => $documents,
-                'aggregations' => $aggregations
+                'aggregations' => $aggregations,
+                'size' => $rawResponse['size']
             ]
         );
     }

lib/internal/Magento/Framework/Search/Response/QueryResponse.php

@@ -29,14 +29,23 @@ class QueryResponse implements ResponseInterface
      */
     protected $aggregations;
 
+    /**
+     * Total count of collection
+     *
+     * @var int
+     */
+    protected $totalCount;
+
     /**
      * @param Document[] $documents
      * @param AggregationInterface $aggregations
+     * @param Total size int $size
      */
-    public function __construct(array $documents, AggregationInterface $aggregations)
+    public function __construct(array $documents, AggregationInterface $aggregations, int $size = 0)
     {
         $this->documents = $documents;
         $this->aggregations = $aggregations;
+        $this->totalCount = $size;
     }
 
     /**
@@ -65,4 +74,12 @@ public function getAggregations()
     {
         return $this->aggregations;
     }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getTotalCount()
+    {
+        return $this->totalCount;
+    }
 }

lib/internal/Magento/Framework/Search/SearchResponseBuilder.php

@@ -42,11 +42,10 @@ public function build(ResponseInterface $response)
     {
         /** @var \Magento\Framework\Api\Search\SearchResult $searchResult */
         $searchResult = $this->searchResultFactory->create();
-
         $documents = iterator_to_array($response);
         $searchResult->setItems($documents);
         $searchResult->setAggregations($response->getAggregations());
-        $searchResult->setTotalCount(count($documents));
+        $searchResult->setTotalCount($response->getTotalCount());
 
         return $searchResult;
     }