pkgs/http/lib/src/abortable.dart

// Copyright (c) 2025, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

import 'dart:async';

import 'base_request.dart';
import 'client.dart';
import 'exception.dart';
import 'streamed_response.dart';

/// An HTTP request that can be aborted before it completes.
abstract mixin class Abortable implements BaseRequest {
  /// Completion of this future aborts this request (if the client supports
  /// abortion).
  ///
  /// Requests/responses may be aborted at any time during their lifecycle.
  ///
  ///  * If completed before the request has been finalized and sent,
  ///    [Client.send] completes with [RequestAbortedException].
  ///  * If completed after the response headers are available, or whilst
  ///    streaming the response, clients inject [RequestAbortedException] into
  ///    the [StreamedResponse.stream] then close the stream.
  ///  * If completed after the response is fully complete, there is no effect.
  ///
  /// A common pattern is aborting a request when another event occurs (such as
  /// a user action): use a [Completer] to implement this. To implement a
  /// timeout (to abort the request after a set time has elapsed), use
  /// [Future.delayed].
  ///
  /// This future must not complete with an error.
  ///
  /// Some clients may not support abortion, or may not support this trigger.
  abstract final Future<void>? abortTrigger;
}

/// Thrown when an HTTP request is aborted.
///
/// This exception is triggered when [Abortable.abortTrigger] completes.
class RequestAbortedException extends ClientException {
  RequestAbortedException([Uri? uri])
      : super('Request aborted by `abortTrigger`', uri);
}