- State
- Initial State
- Mutable State
- Progress
- Redirect Handling
- Cached Response Handling
- URLCredential
- Validator
- URLRequests
- HTTPURLResponse
- Tasks
- Metrics
- Retry Count
- Error
State
State
State는 다음과 같이 구성되어 있습니다.
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public enum State {
/// Initial state of the `Request`.
case initialized
/// `State` set when `resume()` is called. Any tasks created for the `Request` will have `resume()` called on
/// them in this state.
case resumed
/// `State` set when `suspend()` is called. Any tasks created for the `Request` will have `suspend()` called on
/// them in this state.
case suspended
/// `State` set when `cancel()` is called. Any tasks created for the `Request` will have `cancel()` called on
/// them. Unlike `resumed` or `suspended`, once in the `cancelled` state, the `Request` can no longer transition
/// to any other state.
case cancelled
/// `State` set when all response serialization completion closures have been cleared on the `Request` and
/// enqueued on their respective queues.
case finished
/// Determines whether `self` can be transitioned to the provided `State`.
func canTransitionTo(_ state: State) -> Bool {
switch (self, state) {
case (.initialized, _):
return true
case (_, .initialized), (.cancelled, _), (.finished, _):
return false
case (.resumed, .cancelled), (.suspended, .cancelled), (.resumed, .suspended), (.suspended, .resumed):
return true
case (.suspended, .suspended), (.resumed, .resumed):
return false
case (_, .finished):
return true
}
}
initialized(초기 상태)resumed(task가 resume되었을 때의 상태)suspended(중지되었을 때의 상태)cancelled(취소되었을 때의 상태)finished(완료되었을 때의 상태)
총 5가지 상태가 존재합니다. 상태전이 가능의 여부는 canTransitionTo(_: State) 로 체크할 수 있습니다.
Initial State
State는 시점에 따라 크게 Initial State와 Mutable State로 나뉩니다.
그중 Initial State때 세팅되는 프로퍼티들은 다음과 같습니다.
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/// `UUID` providing a unique identifier for the `Request`, used in the `Hashable` and `Equatable` conformances.
public let id: UUID
/// The serial queue for all internal async actions.
public let underlyingQueue: DispatchQueue
/// The queue used for all serialization actions. By default it's a serial queue that targets `underlyingQueue`.
public let serializationQueue: DispatchQueue
/// `EventMonitor` used for event callbacks.
public let eventMonitor: EventMonitor?
/// The `Request`'s interceptor.
public let interceptor: RequestInterceptor?
/// The `Request`'s delegate.
public private(set) weak var delegate: RequestDelegate?
Request를 구분짓는 id값, 지정가능한 DispatchQueue, eventMonitor, interceptor, delegate 등이 있습니다.
위의 값들은 public이기 때문에 라이브러리를 사용하는 경우에도 꺼내 쓸 수 있습니다.
반면 Mutable State의 값들은 internal이라 꺼내 쓸 수 없으니 다루지 않도록 하겠습니다.
현재 상태 확인법
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/// `State` of the `Request`.
public var state: State { $mutableState.state }
/// Returns whether `state` is `.initialized`.
public var isInitialized: Bool { state == .initialized }
/// Returns whether `state is `.resumed`.
public var isResumed: Bool { state == .resumed }
/// Returns whether `state` is `.suspended`.
public var isSuspended: Bool { state == .suspended }
/// Returns whether `state` is `.cancelled`.
public var isCancelled: Bool { state == .cancelled }
/// Returns whether `state` is `.finished`.
public var isFinished: Bool { state == .finished }
state라는 변수와 함께 각종 상황이 진행되었는지를 체크할 수 있는 변수가 주어지므로
이를 통해 현재 Request의 상태를 확인할 수 있습니다.
기타
Requests
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/// All `URLRequests` created on behalf of the `Request`, including original and adapted requests.
public var requests: [URLRequest] { $mutableState.requests }
/// First `URLRequest` created on behalf of the `Request`. May not be the first one actually executed.
public var firstRequest: URLRequest? { requests.first }
/// Last `URLRequest` created on behalf of the `Request`.
public var lastRequest: URLRequest? { requests.last }
/// Current `URLRequest` created on behalf of the `Request`.
public var request: URLRequest? { lastRequest }
/// `URLRequest`s from all of the `URLSessionTask`s executed on behalf of the `Request`. May be different from
/// `requests` due to `URLSession` manipulation.
public var performedRequests: [URLRequest] { $mutableState.read { $0.tasks.compactMap(\.currentRequest) } }
request를 꺼내 볼 수 있는 연산 프로퍼티들입니다.
이미 진행된 requests만 따로 볼 수 있는 perfromedRequests를 지원합니다.
HTTPURLResponse
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/// `HTTPURLResponse` received from the server, if any. If the `Request` was retried, this is the response of the
/// last `URLSessionTask`.
public var response: HTTPURLResponse? { lastTask?.response as? HTTPURLResponse }
