Add forward plugin

Author: andot

lib/plugins.dart

@@ -8,7 +8,7 @@
 |                                                          |
 | hprose.rpc.plugins library for Dart.                     |
 |                                                          |
-| LastModified: Mar 6, 2019                                |
+| LastModified: Mar 28, 2020                               |
 | Author: Ma Bingyao <[email protected]>                    |
 |                                                          |
 \*________________________________________________________*/
@@ -22,7 +22,11 @@ import 'dart:math';
 import 'dart:convert';
 import 'dart:typed_data';
 import 'io.dart';
-import 'core.dart';
+import 'core.dart'
+    // ignore: uri_does_not_exist
+    if (dart.library.html) 'browser.dart'
+    // ignore: uri_does_not_exist
+    if (dart.library.io) 'rpc.dart';
 
 part 'src/rpc/plugins/log.dart';
 part 'src/rpc/plugins/limiter.dart';
@@ -33,3 +37,4 @@ part 'src/rpc/plugins/loadbalance.dart';
 part 'src/rpc/plugins/push.dart';
 part 'src/rpc/plugins/reverse.dart';
 part 'src/rpc/plugins/timeout.dart';
+part 'src/rpc/plugins/forward.dart';

lib/src/rpc/plugins/forward.dart

@@ -0,0 +1,45 @@
+/*--------------------------------------------------------*\
+|                                                          |
+|                          hprose                          |
+|                                                          |
+| Official WebSite: https://hprose.com                     |
+|                                                          |
+| forward.dart                                             |
+|                                                          |
+| Forward plugin for Dart.                                 |
+|                                                          |
+| LastModified: Mar 28, 2020                               |
+| Author: Ma Bingyao <[email protected]>                    |
+|                                                          |
+\*________________________________________________________*/
+
+part of hprose.rpc.plugins;
+
+class Forward {
+  Client _client;
+  Duration timeout;
+  Forward([List<String> uris]) {
+    _client = new Client(uris);
+  }
+
+  Future<Uint8List> ioHandler(
+      Uint8List request, Context context, NextIOHandler next) {
+    final clientContext = new ClientContext(timeout: timeout);
+    clientContext.init(_client);
+    return _client.request(request, clientContext);
+  }
+
+  Future invokeHandler(
+      String name, List args, Context context, NextInvokeHandler next) {
+    final clientContext = new ClientContext(timeout: timeout);
+    return _client.invoke(name, args, clientContext);
+  }
+
+  void use<Handler>(Handler handler) {
+    _client.use(handler);
+  }
+
+  void unuse<Handler>(Handler handler) {
+    _client.unuse(handler);
+  }
+}

test/hprose_rpc_test.dart

@@ -503,4 +503,22 @@ void main() {
     await provider.close();
     server.close();
   });
+
+  test('forward', () async {
+    final service = Service();
+    service.addMethod(hello);
+    final server = await ServerSocket.bind('127.0.0.1', 8412);
+    service.bind(server);
+
+    final service2 = Service();
+    service2.use(new Forward(["tcp://127.0.0.1:8412"]).ioHandler);
+    final server2 = await HttpServer.bind('127.0.0.1', 8000);
+    service2.bind(server2);
+
+    final client = Client(['http://127.0.0.1:8000/']);
+    final proxy = client.useService();
+    expect(await proxy.hello<String>('world'), equals('hello world'));
+    server2.close();
+    server.close();
+  });
 }