Add Flatbuffers support to NodeJS bindings

CHANGELOG.md

@@ -1,6 +1,7 @@
 # Unreleased
   - Changes from 5.26.0
     - API:
+      - ADDED: Add Flatbuffers support to NodeJS bindings. [#6338](https://github.com/Project-OSRM/osrm-backend/pull/6338)
       - CHANGED: Add `data_version` field to responses of all services. [#5387](https://github.com/Project-OSRM/osrm-backend/pull/5387)
       - FIXED: Use Boost.Beast to parse HTTP request. [#6294](https://github.com/Project-OSRM/osrm-backend/pull/6294)
       - FIXED: Fix inefficient osrm-routed connection handling [#6113](https://github.com/Project-OSRM/osrm-backend/pull/6113)

docs/nodejs/api.md

@@ -63,8 +63,8 @@ Returns the fastest route between two or more coordinates while visiting the way
     -   `options.approaches` **[Array](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Array)?** Keep waypoints on curb side. Can be `null` (unrestricted, default) or `curb`.
                          `null`/`true`/`false`
     -   `options.waypoints` **[Array](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Array)?** Indices to coordinates to treat as waypoints. If not supplied, all coordinates are waypoints.  Must include first and last coordinate index.
-    -   `options.snapping` **[String](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)?** Which edges can be snapped to, either `default`, or `any`.  `default` only snaps to edges marked by the profile as `is_startpoint`, `any` will allow snapping to any edge in the routing graph.
     -   `options.format` **[String](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)?** Which output format to use, either `json`, or [`flatbuffers`](https://github.com/Project-OSRM/osrm-backend/tree/master/include/engine/api/flatbuffers).
+    -   `options.snapping` **[String](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)?** Which edges can be snapped to, either `default`, or `any`.  `default` only snaps to edges marked by the profile as `is_startpoint`, `any` will allow snapping to any edge in the routing graph.
 -   `callback` **[Function](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Statements/function)** 
 
 **Examples**
@@ -98,8 +98,8 @@ Note: `coordinates` in the general options only supports a single `{longitude},{
     -   `options.number` **[Number](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number)** Number of nearest segments that should be returned.
         Must be an integer greater than or equal to `1`. (optional, default `1`)
     -   `options.approaches` **[Array](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Array)?** Keep waypoints on curb side. Can be `null` (unrestricted, default) or `curb`.
-    -   `options.snapping` **[String](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)?** Which edges can be snapped to, either `default`, or `any`.  `default` only snaps to edges marked by the profile as `is_startpoint`, `any` will allow snapping to any edge in the routing graph.
     -   `options.format` **[String](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)?** Which output format to use, either `json`, or [`flatbuffers`](https://github.com/Project-OSRM/osrm-backend/tree/master/include/engine/api/flatbuffers).
+    -   `options.snapping` **[String](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)?** Which edges can be snapped to, either `default`, or `any`.  `default` only snaps to edges marked by the profile as `is_startpoint`, `any` will allow snapping to any edge in the routing graph.
 -   `callback` **[Function](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Statements/function)** 
 
 **Examples**
@@ -142,7 +142,6 @@ Optionally returns distance table.
     -   `options.fallback_coordinate` **[String](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)?** Either `input` (default) or `snapped`.  If using a `fallback_speed`, use either the user-supplied coordinate (`input`), or the snapped coordinate (`snapped`) for calculating the as-the-crow-flies distance between two points.
     -   `options.scale_factor` **[Number](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number)?** Multiply the table duration values in the table by this number for more controlled input into a route optimization solver.
     -   `options.snapping` **[String](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)?** Which edges can be snapped to, either `default`, or `any`.  `default` only snaps to edges marked by the profile as `is_startpoint`, `any` will allow snapping to any edge in the routing graph.
-    -   `options.format` **[String](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)?** Which output format to use, either `json`, or [`flatbuffers`](https://github.com/Project-OSRM/osrm-backend/tree/master/include/engine/api/flatbuffers).
     -   `options.annotations` **[Array](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Array)?** Return the requested table or tables in response. Can be `['duration']` (return the duration matrix, default), `[distance']` (return the distance matrix), or `['duration', distance']` (return both the duration matrix and the distance matrix).
 -   `callback` **[Function](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Statements/function)** 
 
@@ -228,7 +227,6 @@ if they can not be matched successfully.
     -   `options.tidy` **[Boolean](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** Allows the input track modification to obtain better matching quality for noisy tracks. (optional, default `false`)
     -   `options.waypoints` **[Array](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Array)?** Indices to coordinates to treat as waypoints.  If not supplied, all coordinates are waypoints.  Must include first and last coordinate index.
     -   `options.snapping` **[String](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)?** Which edges can be snapped to, either `default`, or `any`. `default` only snaps to edges marked by the profile as `is_startpoint`, `any` will allow snapping to any edge in the routing graph.
-    -   `options.format` **[String](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)?** Which output format to use, either `json`, or [`flatbuffers`](https://github.com/Project-OSRM/osrm-backend/tree/master/include/engine/api/flatbuffers).
 -   `callback` **[Function](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Statements/function)** 
 
 **Examples**
@@ -298,7 +296,6 @@ Right now, the following combinations are possible:
     -   `options.destination` **[String](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)** Return route ends at `any` or `last` coordinate. (optional, default `any`)
     -   `options.approaches` **[Array](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Array)?** Keep waypoints on curb side. Can be `null` (unrestricted, default) or `curb`.
     -   `options.snapping` **[String](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)?** Which edges can be snapped to, either `default`, or `any`. `default` only snaps to edges marked by the profile as `is_startpoint`, `any` will allow snapping to any edge in the routing graph.
-    -   `options.format` **[String](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)?** Which output format to use, either `json`, or [`flatbuffers`](https://github.com/Project-OSRM/osrm-backend/tree/master/include/engine/api/flatbuffers).
 -   `callback` **[Function](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Statements/function)** 
 
 **Examples**
@@ -355,7 +352,7 @@ var options = {
     [13.374481201171875, 52.506191342034576]
   ]
 };
-osrm.route(options, { format: "json_buffer" }, function(err, response) {
+osrm.route(options, { format: "buffer" }, function(err, response) {
   if (err) throw err;
   console.log(response.toString("utf-8"));
 });

src/nodejs/node_osrm.cpp

@@ -319,6 +319,7 @@ inline void asyncForTiles(const Nan::FunctionCallbackInfo<v8::Value> &info,
  * @param {Array} [options.approaches] Keep waypoints on curb side. Can be `null` (unrestricted, default) or `curb`.
  *                  `null`/`true`/`false`
  * @param {Array} [options.waypoints] Indices to coordinates to treat as waypoints. If not supplied, all coordinates are waypoints.  Must include first and last coordinate index.
+ * @param {String} [options.format] Which output format to use, either `json`, or [`flatbuffers`](https://github.com/Project-OSRM/osrm-backend/tree/master/include/engine/api/flatbuffers).
  * @param {String} [options.snapping] Which edges can be snapped to, either `default`, or `any`.  `default` only snaps to edges marked by the profile as `is_startpoint`, `any` will allow snapping to any edge in the routing graph.
  * @param {Function} callback
  *
@@ -359,6 +360,7 @@ NAN_METHOD(Engine::route) //
  * @param {Number} [options.number=1] Number of nearest segments that should be returned.
  * Must be an integer greater than or equal to `1`.
  * @param {Array} [options.approaches] Keep waypoints on curb side. Can be `null` (unrestricted, default) or `curb`.
+ * @param {String} [options.format] Which output format to use, either `json`, or [`flatbuffers`](https://github.com/Project-OSRM/osrm-backend/tree/master/include/engine/api/flatbuffers).
  * @param {String} [options.snapping] Which edges can be snapped to, either `default`, or `any`.  `default` only snaps to edges marked by the profile as `is_startpoint`, `any` will allow snapping to any edge in the routing graph.
  * @param {Function} callback
  *
@@ -625,12 +627,13 @@ NAN_METHOD(Engine::trip) //
  * @name Configuration
  * @param {Object} [plugin_config] - Object literal containing parameters for the trip query.
  * @param {String} [plugin_config.format] The format of the result object to various API calls.
- *                                        Valid options are `object` (default), which returns a
+ *                                        Valid options are `object` (default if `options.format` is `json`), which returns a
- * standard Javascript object, as described above, and `json_buffer`, which will return a NodeJS
+ * standard Javascript object, as described above, and `buffer`(default if `options.format` is `flatbuffers`), which will return a NodeJS
- * **[Buffer](https://nodejs.org/api/buffer.html)** object, containing a JSON string. The latter has
+ * **[Buffer](https://nodejs.org/api/buffer.html)** object, containing a JSON string or Flatbuffers object. The latter has
  * the advantage that it can be immediately serialized to disk/sent over the network, and the
  * generation of the string is performed outside the main NodeJS event loop.  This option is ignored
- * by the `tile` plugin.
+ * by the `tile` plugin. Also note that `options.format` set to `flatbuffers` cannot be used with `plugin_config.format` set to `object`.
+ * `json_buffer` is deprecated alias for `buffer`.
  *
  * @example
  * var osrm = new OSRM('network.osrm');
@@ -640,7 +643,7 @@ NAN_METHOD(Engine::trip) //
  *     [13.374481201171875, 52.506191342034576]
  *   ]
  * };
- * osrm.route(options, { format: "json_buffer" }, function(err, response) {
+ * osrm.route(options, { format: "buffer" }, function(err, response) {
  *   if (err) throw err;
  *   console.log(response.toString("utf-8"));
  * });