Removes risk of DDS connection information being split across two stream events, causing JSON decoding to fail. Also updates DDS to close stderr, even in the error case. TEST=Existing service and dartdev tests Change-Id: I5cceab899aac1fa63bd7578dd658b34096722bd3 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/371000 Reviewed-by: Derek Xu <derekx@google.com>
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 preferable or required to communicate with DDS using server-sent events (SSE). DDS has an 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());
}