Add REST enpoints for hashing

Signed-off-by: Marcel Klehr <mklehr@gmx.net>

API.md

@@ -33,8 +33,8 @@ GET
 
 ```json
 {
-    "status": "success",
-    "data": [{ "id": "7", "title": "Google", "tags": ["firsttag"] /*...*/ }]
+	"status": "success",
+	"data": [{ "id": "7", "title": "Google", "tags": ["firsttag"] /*...*/ }]
 }
 ```
 
@@ -62,13 +62,13 @@ POST /index.php/apps/bookmarks/public/rest/v2/bookmark?url=http%3A%2F%2Fgoogle.c
 
 ```json
 {
-    "status": "success",
-    "item": {
-        "id": "7",
-        "url": "http://google.com",
-        "title": "Google"
-        //...
-    }
+	"status": "success",
+	"item": {
+		"id": "7",
+		"url": "http://google.com",
+		"title": "Google"
+		//...
+	}
 }
 ```
 
@@ -92,13 +92,13 @@ GET /index.php/apps/bookmarks/public/rest/v2/bookmark/7
 
 ```json
 {
-    "status": "success",
-    "item": {
-        "id": "7",
-        "url": "http://google.com",
-        "title": "Boogle"
-        //...
-    }
+	"status": "success",
+	"item": {
+		"id": "7",
+		"url": "http://google.com",
+		"title": "Boogle"
+		//...
+	}
 }
 ```
 
@@ -128,13 +128,13 @@ PUT /index.php/apps/bookmarks/public/rest/v2/bookmark/7?record_id=7&title=Boogle
 
 ```json
 {
-    "status": "success",
-    "item": {
-        "id": "7",
-        "url": "http://google.com",
-        "title": "Boogle"
-        //...
-    }
+	"status": "success",
+	"item": {
+		"id": "7",
+		"url": "http://google.com",
+		"title": "Boogle"
+		//...
+	}
 }
 ```
 
@@ -292,7 +292,7 @@ POST /index.php/apps/bookmarks/public/rest/v2/folder
 ### Edit folders
 
 ```
-PUT /index.php/apps/bookmarks/public/rest/v2/folder
+PUT /index.php/apps/bookmarks/public/rest/v2/folder/:id
 ```
 
 Parameters:
@@ -312,6 +312,46 @@ PUT /index.php/apps/bookmarks/public/rest/v2/folder/5
 { "status": "success", "item": {"id": 5, "title": "physical activity", "parent_folder": "-1"}}
 ```
 
+### Hash folders
+
+```
+GET /index.php/apps/bookmarks/public/rest/v2/folder/:id/hash
+```
+
+Parameters:
+
+- (optional) `fields[]`: All bookmarks fields that should be hashed (default: `title`, `url`)
+
+Example:
+
+```
+GET /index.php/apps/bookmarks/public/rest/v2/folder/5/hash
+```
+
+```
+{ "status": "success", "data": "65432378"}
+```
+
+Description:
+
+This endpoint is useful for synchronizing data between the server and a client. By comparing the hash of the data on your client with the hash from the server you can figure out which parts of the tree have changed.
+
+The algorithm works as follows:
+
+- Hash endpoint: `hashFolder(id, fields)`
+- `hashFolder(id, fields)`
+  - for all children of the folder
+    - if it's a folder
+      - add to `childrenHashes`: `hashFolder(folderId, fields)`
+    - if it's a bookmark
+      - add to `childrenHashes`: `hashBookmark(bookmarkId, fields)`
+  - Return `murmur2(to_json({title: folderTitle, children: childrenHashes}))`
+- `hashBookmark(id, fields)`
+  - for all entries in `fields`
+    - set `object[field]` to the value of the associated field of the bookmark
+  - Return `murmur2(to_json(object))`
+- `murmur2`: [The murmur2 hashing algorithm](https://en.wikipedia.org/wiki/MurmurHash)
+
 ### Delete folders
 
 ```

appinfo/routes.php

@@ -47,6 +47,7 @@ $application->registerRoutes($this, ['routes' => [
 	['name' => 'internal_folders#add_folder', 'url' => '/folder', 'verb' => 'POST'],
 	['name' => 'internal_folders#edit_folder', 'url' => '/folder/{folderId}', 'verb' => 'PUT'],
 	['name' => 'internal_folders#delete_folder', 'url' => '/folder/{folderId}', 'verb' => 'DELETE'],
+	['name' => 'internal_folders#hash_folder', 'url' => '/folder/{folderId}/hash', 'verb' => 'GET'],
 	['name' => 'internal_folders#get_folder_children_order', 'url' => '/folder/{folderId}/childorder', 'verb' => 'GET'],
 	['name' => 'internal_folders#set_folder_children_order', 'url' => '/folder/{folderId}/childorder', 'verb' => 'PATCH'],
 	['name' => 'internal_folders#add_to_folder', 'url' => '/folder/{folderId}/bookmarks/{bookmarkId}', 'verb' => 'POST'],
@@ -70,6 +71,7 @@ $application->registerRoutes($this, ['routes' => [
 	['name' => 'folders#add_folder', 'url' => '/public/rest/v2/folder', 'verb' => 'POST'],
 	['name' => 'folders#edit_folder', 'url' => '/public/rest/v2/folder/{folderId}', 'verb' => 'PUT'],
 	['name' => 'folders#delete_folder', 'url' => '/public/rest/v2/folder/{folderId}', 'verb' => 'DELETE'],
+	['name' => 'folders#hash_folder', 'url' => '/public/rest/v2/folder/{folderId}/hash', 'verb' => 'GET'],
 	['name' => 'folders#get_folder_children_order', 'url' => '/public/rest/v2/folder/{folderId}/childorder', 'verb' => 'GET'],
 	['name' => 'folders#set_folder_children_order', 'url' => '/public/rest/v2/folder/{folderId}/childorder', 'verb' => 'PATCH'],
 	['name' => 'folders#add_to_folder', 'url' => '/public/rest/v2/folder/{folderId}/bookmarks/{bookmarkId}', 'verb' => 'POST'],

lib/Controller/Rest/FoldersController.php

@@ -118,6 +118,24 @@ class FoldersController extends ApiController {
 		}
 	}
 
+	/**
+	 * @param int $folderId
+	 * @param string[] $fields
+	 * @return JSONResponse
+	 *
+	 * @NoAdminRequired
+	 * @NoCSRFRequired
+	 * @CORS
+	 */
+	public function hashFolder($folderId, $fields=['title', 'url']) {
+		try {
+			$hash = $this->bookmarks->hashFolder($this->userId, $folderId, $fields);
+			return new JSONResponse(['status' => 'success', 'data' => $hash]);
+		} catch (Exception $e) {
+			return new JSONResponse(['status' => 'error', 'data' => $e->getMessage()], Http::STATUS_BAD_REQUEST);
+		}
+	}
+
 
 	/**
 	 * @param int $folderId

lib/Controller/Rest/InternalFoldersController.php

@@ -102,6 +102,17 @@ class InternalFoldersController extends ApiController {
 		return $this->controller->editFolder($folderId, $title, $parent_folder);
 	}
 
+	/**
+	 * @param int $folderId
+	 * @param string[] $fields
+	 * @return JSONResponse
+	 *
+	 * @NoAdminRequired
+	 */
+	public function hashFolder($folderId, $fields=['title', 'url']) {
+		return $this->controller->hashFolder($folderId, $fields);
+	}
+
 	/**
 	 * @param int $root the id of the root folder whose descendants to return
 	 * @param int $layers the number of layers of hierarchy too return