[Breaking Change Request] Support abort() in HttpClientRequest in Dart:IO #41904
Description
Summary
With current APIs in Dart:IO, there is no way to abort the HttpClientRequest. Once HttpClientRequest has been sent, the request cannot be canceled until HttpClientResponse comes back. See the example below:
HttpClient client = new HttpClient();
client.getUrl(Uri.parse("http://www.example.com/"))
.then((HttpClientRequest request) {
// Optionally set up headers...
request.write();
// Optionally write to the request object...
// Then call close.
...
return request.close();
})
.then((HttpClientResponse response) {
// Process the response.
...
});Abort() will allow users to stop waiting for HttpClientResponse, so users can abort the request if it takes too long.
Function signature
abort([Object? exception, StackTrace? stackTrace]);The intended behavior
- The future returned by
close()will complete withexceptionandstackTraceif abort() is called prior toHttpClientResponsebeing available. The default value forexceptionandstackTracewill beHttpExceptionandStackTrace.empty. - Data cannot be sent through
IOSink's API after abort(). - In case of
HttpClientResponsereturning beforeabort, abort() will not make any effect.
Expected use case
HttpClient client = new HttpClient();
client.getUrl(Uri.parse("http://www.example.com/"))
.then((HttpClientRequest request) {
// Optionally set up headers...
request.write();
// Optionally write to the request object...
// Then call close.
Timer(Duration(seconds: 1), () {
request.abort(Exception("Customized value"));
});
return request.close();
})
.then((HttpClientResponse response) {
// Process the response.
...
}, onError: (e) {
// e will be `Exception("Customized value")`
});Expected impact
All classes extends or implements HttpClientRequest in Dart:IO will need to update accordingly.
Proposed Implementation
https://dart-review.googlesource.com/c/sdk/+/147339