54 lines
2.2 KiB
Swift
54 lines
2.2 KiB
Swift
// Copyright 2018 Google Inc. All rights reserved.
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at:
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
import Dispatch
|
|
|
|
/// Wait until any of the given promises are fulfilled.
|
|
/// If one of the given promises is rejected, then the returned promise is rejected with same
|
|
/// error. If any other arbitrary value or `Error` appears in the array instead of `Promise`,
|
|
/// it's implicitly considered a pre-fulfilled or pre-rejected `Promise` correspondingly.
|
|
/// - parameters:
|
|
/// - queue: A queue to dispatch on.
|
|
/// - promises: Promises to wait for.
|
|
/// - returns: First promise, among the given ones, which was fulfilled.
|
|
public func race<Value>(
|
|
on queue: DispatchQueue = .promises,
|
|
_ promises: Promise<Value>...
|
|
) -> Promise<Value> {
|
|
return race(on: queue, promises)
|
|
}
|
|
|
|
/// Wait until any of the given promises are fulfilled.
|
|
/// If one of the given promises is rejected, then the returned promise is rejected with same
|
|
/// error. If any other arbitrary value or `Error` appears in the array instead of `Promise`,
|
|
/// it's implicitly considered a pre-fulfilled or pre-rejected `Promise` correspondingly.
|
|
/// - parameters:
|
|
/// - queue: A queue to dispatch on.
|
|
/// - promises: Promises to wait for.
|
|
/// - returns: First promise, among the given ones, which was fulfilled.
|
|
public func race<Value>(
|
|
on queue: DispatchQueue = .promises,
|
|
_ promises: [Promise<Value>]
|
|
) -> Promise<Value> {
|
|
let promises = promises.map { $0.objCPromise }
|
|
let promise = Promise<Value>(
|
|
Promise<Value>.ObjCPromise<AnyObject>.__onQueue(queue, race: promises)
|
|
)
|
|
// Keep Swift wrapper alive for chained promises until `ObjCPromise` counterpart is resolved.
|
|
promises.forEach {
|
|
$0.__addPendingObject(promise)
|
|
}
|
|
return promise
|
|
}
|