延迟任务工具包 (DefferedTaskKit)

延迟任务工具包是一个简单的库，用于包装可以稍后执行的闭包。

延迟任务 (DefferedTask)

DefferedTask 处理 Value 类型，而 DefferedResult 处理 Result 类型。

重要提示

任务只有在通过 'onComplete' 方法订阅后才会被执行。如果你不订阅任务，它将永远不会被执行。
默认情况下，任务是“自保留”的，你不需要在变量中保存任务的引用。使用 'weakify()' 方法来防止循环引用。
如果需要，你可以处理任务的 'deinit' (析构) 方法。

延迟任务 (DefferedTask)

DefferedTask<Int> { completion in
    print("start task")
    DispatchQueue.main.asyncAfter(deadline: .now() + 1) {
        completion(10)
        print("end task")
    }
} onDeinit: {
    print("onDeinit")
}
.beforeComplete { result in
    print("beforeComplete: \(result)") // print 10
}
.afterComplete { result in
    print("afterComplete: \(result)") // print 10
}
.set(userInfo: "subject")
.strongify()
.map { value in
    return value * 2
}
.beforeComplete { result in
    print("beforeComplete: \(result)") // print 20
}
.afterComplete { result in
    print("afterComplete: \(result)") // print 20
}
.onComplete { result in
    print("onComplete: \(result)") // print 20
}

控制台输出

start task
beforeComplete: 10
beforeComplete: 20
onComplete: 20
afterComplete: 20
afterComplete: 10
onDeinit
end task

待处理任务 (PendingTask)

特殊的任务，在执行单个主要任务时缓存其他任务。

let pending: PendingTask<Int> = .init()

for i in 0..<10 {
    pending.current { completion in
        print("start main task")
        DispatchQueue.main.asyncAfter(deadline: .now() + 1) {
            completion(10)
            print("end main task")
        }
    }.onComplete { _ in
        print("onComplete: \(i)")
    }
}

控制台输出

start main task
onComplete: 0
onComplete: 1
onComplete: 2
onComplete: 3
onComplete: 4
onComplete: 5
onComplete: 6
onComplete: 7
onComplete: 8
onComplete: 9
end main task

轮询任务 (PollingTask)

特殊的任务，以 idleTimeInterval (空闲时间间隔) 和 retryCount (重试次数) 轮询主要任务。

var idx = 0
PollingTask<Int>(idleTimeInterval: 1,
                 retryCount: 5,
                 generator: {
    return .init { completion in
        print("start main task")
        DispatchQueue.main.asyncAfter(deadline: .now() + 1) {
            completion(idx)
            idx += 1
            print("end main task")
        }
    }
},
                 shouldRepeat: { idx in
    print("shouldRepeat \(idx)")
    return idx < 4
},
                 response: { idx in
    print("response: \(idx)")
})
.start()
.onComplete { result in
    print("completed \(result)")
}

控制台输出

start main task
response: 0
shouldRepeat 0
end main task
start main task
response: 1
shouldRepeat 1
end main task
start main task
response: 2
shouldRepeat 2
end main task
start main task
response: 3
shouldRepeat 3
end main task
start main task
response: 4
shouldRepeat 4
completed 4
end main task