Alamofire(4)

1:timeline时间轴

1）Alamofire的时间轴记录请求从生到死的时间节点信息，（时光🐔🐔🐔🐔🐔）。

 public init(
        requestStartTime: CFAbsoluteTime = 0.0, 
        initialResponseTime: CFAbsoluteTime = 0.0,
        requestCompletedTime: CFAbsoluteTime = 0.0,
        serializationCompletedTime: CFAbsoluteTime = 0.0)
    {
        self.requestStartTime = requestStartTime  //初始化请求时间
        self.initialResponseTime = initialResponseTime // 从服务器接收或发送第一个字节的时间
        self.requestCompletedTime = requestCompletedTime // 请求完成时间
        self.serializationCompletedTime = serializationCompletedTime // 响应序列化完成时间

        self.latency = initialResponseTime - requestStartTime //从请求开始到服务器的初始响应的时间间隔（以秒为单位）
        self.requestDuration = requestCompletedTime - requestStartTime//从请求开始到请求完成的时间间隔（以秒为单位）
        self.serializationDuration = serializationCompletedTime - requestCompletedTime // 从请求完成到响应序列化完成的时间间隔
        self.totalDuration = serializationCompletedTime - requestStartTime // 从请求开始到完成时间响应序列化的时间间隔
    }

2）应用
Request的扩展

extension Request {
    var timeline: Timeline {
        let requestStartTime = self.startTime ?? CFAbsoluteTimeGetCurrent()
        let requestCompletedTime = self.endTime ?? CFAbsoluteTimeGetCurrent()
        let initialResponseTime = self.delegate.initialResponseTime ?? requestCompletedTime

        return Timeline(
            requestStartTime: requestStartTime,   //调用resume的时候开启
            initialResponseTime: initialResponseTime, //queue.addOperation 控制
            requestCompletedTime: requestCompletedTime, // timeline（） 
            serializationCompletedTime: CFAbsoluteTimeGetCurrent() // response回调发起的时间
        )
    }
}

response 调用

        timeline: Timeline = Timeline(),

2：adapter适配器和retrier重连

RequestAdapter 请求适配器，目的是自定义修改请求，一个典型的例子是为每一个请求调价Token请求头
RequestRetrier 请求重试器， 目的是控制请求的重试机制，一个典型的例子是当某个特殊的请求失败后，是否重试。
遵守RequestAdapter、RequestRetrier协议，内容需要自己实现

public protocol RequestAdapter {
    func adapt(_ urlRequest: URLRequest) throws -> URLRequest
}

public protocol RequestRetrier {
    func should(_ manager: SessionManager, retry request: Request, with error: Error, completion: @escaping RequestRetryCompletion)
}

具体使用

class LGAdapter: RequestAdapter,RequestRetrier{
    func should(_ manager: SessionManager, retry request: Request, with error: Error, completion: @escaping RequestRetryCompletion) {
        print("manager = \(manager)")
        print("request = \(request)")
        print("error = \(error)")
        completion(true,1)
        
        completion(false,0)
    }
    
    func adapt(_ urlRequest: URLRequest) throws -> URLRequest {
        // token
        // 1: request 处理
        // 2: request 重定向
        var request = urlRequest
        request.setValue("lgcoociToken", forHTTPHeaderField: "lgtoken")
        let newUrlRequest = URLRequest.init(url: URL(string: "http://www.douban.com/j/app/radio/channels")!)
        return newUrlRequest
    }
}

在使用的时候直接调用。

3：request

1）DataRequest
2）DownloadRequest

public enum Result<Value> {
    case success(Value)
    case failure(Error)

    /// Returns `true` if the result is a success, `false` otherwise.
    public var isSuccess: Bool {
        switch self {
        case .success:
            return true
        case .failure:
            return false
        }
    }

    /// Returns `true` if the result is a failure, `false` otherwise.
    public var isFailure: Bool {
        return !isSuccess
    }

    /// Returns the associated value if the result is a success, `nil` otherwise.
    public var value: Value? {
        switch self {
        case .success(let value):
            return value
        case .failure:
            return nil
        }
    }

    /// Returns the associated error value if the result is a failure, `nil` otherwise.
    public var error: Error? {
        switch self {
        case .success:
            return nil
        case .failure(let error):
            return error
        }
    }
}

//标示请求成功或者失败，成功有成功Value失败有失败的Error。

4:response

1）DataResponse

dataResponse.jpg

2）DefaultDownloadResponse
3）DownloadResponse
4）DefaultDataResponse