added DiffTaskResult Entity and Mapper

lib/Db/DiffTaskResult.php

@@ -0,0 +1,48 @@
+<?php
+namespace OCA\GroupfolderFilesystemSnapshots\Db;
+
+use JsonSerializable;
+
+use OCP\AppFramework\Db\Entity;
+
+class DiffTaskResult extends Entity implements JsonSerializable {
+
+    protected $taskId;
+    protected $timestamp;
+    protected $type;
+
+    protected $beforeFileExists;
+    protected $beforePath;
+    protected $beforeSize;
+
+    protected $currentFileExists;
+    protected $currentPath;
+    protected $currentSize;
+
+    public function __construct() {
+        $this->addType('id','integer');
+        $this->addType('taskId','integer');
+        $this->addType('beforeFileExists','boolean');
+        $this->addType('beforeSize','integer');
+        $this->addType('currentFileExists','boolean');
+        $this->addType('currentSize','integer');
+    }
+
+    public function jsonSerialize() {
+        return [
+            'id' => $this->id,
+            'taskId' => $this->taskId,
+            'type' => $this->type,
+            'before' => [
+                'fileExists' => $this->beforeFileExists,
+                'path' => $this->beforePath,
+                'size' => $this->beforeSize,
+            ],
+            'current' => [
+                'fileExists' => $this->currentFileExists,
+                'path' => $this->currentPath,
+                'size' => $this->currentSize,
+            ]
+        ];
+    }
+}

lib/Db/DiffTaskResultMapper.php

@@ -0,0 +1,36 @@
+<?php
+namespace OCA\GroupfolderFilesystemSnapshots\Db;
+
+use OCP\IDBConnection;
+use OCP\AppFramework\Db\QBMapper;
+
+/**
+ * @extends QBMapper<DiffTaskResult>
+ */
+class DiffTaskResultMapper extends QBMapper {
+
+    public function __construct(IDBConnection $db) {
+        parent::__construct($db, 'groupfolder_snapshots_task_results', DiffTaskResult::class);
+    }
+
+    public function find(int $id) {
+        $qb = $this->db->getQueryBuilder();
+
+        $qb->select('*')
+             ->from($this->getTableName())
+             ->where($qb->expr()->eq('id', $qb->createNamedParameter($id)));
+
+        return $this->findEntity($qb);
+    }
+
+    public function findAll(int $taskId) {
+        $qb = $this->db->getQueryBuilder();
+
+        $qb->select('*')
+           ->from($this->getTableName())
+           ->where($qb->expr()->eq('task_id', $qb->createNamedParameter($taskId)));
+
+        return $this->findEntities($qb);
+    }
+
+}