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,
+            ]
+        ];
+    }
+}