Ben Konyi
a99b92c252
Avoids a LateInitializationError that could occur when the VM service connection goes down during DDS startup. Done by delaying error reporting until after DDS has completed its initial startup flow, ensuring that all relevant state has already been initialized when we try to cleanup. Fixes https://github.com/flutter/flutter/issues/86361 Change-Id: I2b357bfb95c759d301ab48bce9fe1c28871d5e08 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/206672 Commit-Queue: Ben Konyi <bkonyi@google.com> Reviewed-by: Zach Anderson <zra@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 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());
}