Provide an API to dart:developer to control the web server hosting the Service Protocol

sdk/lib/vmservice/vmservice.dart

Index: sdk/lib/vmservice/vmservice.dart
diff --git a/sdk/lib/vmservice/vmservice.dart b/sdk/lib/vmservice/vmservice.dart
index a56c2932d4e40df002f369d2ffabe7cb1f04517b..a7dcce7ea2cb15133ba56019ca2061f447e43c09 100644
--- a/sdk/lib/vmservice/vmservice.dart
+++ b/sdk/lib/vmservice/vmservice.dart
@@ -7,6 +7,7 @@ library dart._vmservice;
 import 'dart:async';
 import 'dart:collection';
 import 'dart:convert';
+import 'dart:developer' show ServiceProtocolInfo;
 import 'dart:isolate';
 import 'dart:typed_data';
 
@@ -19,7 +20,7 @@ part 'running_isolates.dart';
 part 'message.dart';
 part 'message_router.dart';
 
-final RawReceivePort isolateLifecyclePort = new RawReceivePort();
+final RawReceivePort isolateControlPort = new RawReceivePort();
 final RawReceivePort scriptLoadPort = new RawReceivePort();
 
 abstract class IsolateEmbedderData {
@@ -125,6 +126,12 @@ typedef Future<List<int>> ReadFileCallback(Uri path);
 /// Called to list all files under some path.
 typedef Future<List<Map<String,String>>> ListFilesCallback(Uri path);
 
+/// Called when we need information about the server.
+typedef Future<Uri> ServerInformationCallback();
+
+/// Called when we want to [enable] or disable the web server.
+typedef Future<Uri> WebServerControlCallback(bool enable);
+
 /// Hooks that are setup by the embedder.
 class VMServiceEmbedderHooks {
   static ServerStartCallback serverStart;
@@ -136,6 +143,8 @@ class VMServiceEmbedderHooks {
   static WriteStreamFileCallback writeStreamFile;
   static ReadFileCallback readFile;
   static ListFilesCallback listFiles;
+  static ServerInformationCallback serverInformation;
+  static WebServerControlCallback webServerControl;
 }
 
 class VMService extends MessageRouter {
@@ -194,6 +203,27 @@ class VMService extends MessageRouter {
     }
   }
 
+  Future<Null> _serverMessageHandler(int code, SendPort sp, bool enable) async {
+    switch (code) {
+      case Constants.WEB_SERVER_CONTROL_MESSAGE_ID:
+        if (VMServiceEmbedderHooks.webServerControl == null) {
+          sp.send(null);
+          return;
+        }
+        Uri uri = await VMServiceEmbedderHooks.webServerControl(enable);
+        sp.send(uri);
+      break;
+      case Constants.SERVER_INFO_MESSAGE_ID:
+        if (VMServiceEmbedderHooks.serverInformation == null) {
+          sp.send(null);
+          return;
+        }
+        Uri uri = await VMServiceEmbedderHooks.serverInformation();
+        sp.send(uri);
+      break;
+    }
+  }
+
   Future _exit() async {
     // Stop the server.
     if (VMServiceEmbedderHooks.serverStop != null) {
@@ -201,7 +231,7 @@ class VMService extends MessageRouter {
     }
 
     // Close receive ports.
-    isolateLifecyclePort.close();
+    isolateControlPort.close();
     scriptLoadPort.close();
 
     // Create a copy of the set as a list because client.disconnect() will
@@ -233,6 +263,13 @@ class VMService extends MessageRouter {
         _exit();
         return;
       }
+      if (message.length == 3) {
+        // This is a message interacting with the web server.
+        assert((message[0] == Constants.WEB_SERVER_CONTROL_MESSAGE_ID) ||
+               (message[0] == Constants.SERVER_INFO_MESSAGE_ID));
+        _serverMessageHandler(message[0], message[1], message[2]);
+        return;
+      }
       if (message.length == 4) {
         // This is a message informing us of the birth or death of an
         // isolate.
@@ -244,7 +281,7 @@ class VMService extends MessageRouter {
   }
 
   VMService._internal()
-      : eventPort = isolateLifecyclePort {
+      : eventPort = isolateControlPort {
     eventPort.handler = messageHandler;
   }
 
@@ -425,8 +462,8 @@ class VMService extends MessageRouter {
 }
 
 RawReceivePort boot() {
-  // Return the port we expect isolate startup and shutdown messages on.
-  return isolateLifecyclePort;
+  // Return the port we expect isolate control messages on.
+  return isolateControlPort;
 }
 
 void _registerIsolate(int port_id, SendPort sp, String name) {