Files
sdk/pkg/dds
Ben Konyi c36ba8b50c [ package:dds ] Improve DDS error handling, add tests
Added tests to try and emulate failures reported in flutter_tools crash
reports. Used these tests to update error handling and get a better
understanding of exception scenarios.

Change-Id: Ie72822dafcc6373ebfeea543d93b934c0d0687f5
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/172420
Reviewed-by: Jonah Williams <jonahwilliams@google.com>
Commit-Queue: Ben Konyi <bkonyi@google.com>
2020-11-17 00:00:45 +00:00
..

A package used to spawn the Dart Developer Service (DDS), which is used to communicate with a Dart VM Service instance and provide extended functionality to the core VM Service Protocol.

Functionality

Existing VM Service clients can issue both HTTP, websocket, and SSE requests to a running DDS instance as if it were an instance of the VM Service itself. If a request corresponds to an RPC defined in the VM Service Protocol, DDS will forward the request and return the response from the VM Service. Requests corresponding to an RPC defined in the DDS Protocol will be handled directly by the DDS instance.

SSE Support

For certain web clients it may be preferrable or required to communicate with DDS using server-sent events (SSE). DDS has a SSE handler listening for requests on /$debugHandler.

SSE and package:vm_service example

import 'package:sse/sse.dart';
import 'package:vm_service/vm_service.dart';

void main() {
  // Establish connection with DDS using SSE.
  final ddsChannel = SseClient('${ddsUri}\$debugHandler');

  // Wait for ddsChannel to be established
  await ddsChannel.onOpen.first;

  // Initialize VmService using the sink and stream from ddsChannel.
  final vmService = VmService(
    ddsChannel.stream,
    (e) => ddsChannel.sink.add(e),
  );

  // You're ready to query DDS and the VM service!
  print(await vmService.getVersion());
}