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weibo/Pods/Alamofire/Source/Request.swift

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//
// Request.swift
//
// Copyright (c) 2014-2020 Alamofire Software Foundation (http://alamofire.org/)
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//
import Foundation
/// `Request` is the common superclass of all Alamofire request types and provides common state, delegate, and callback
/// handling.
public class Request {
/// State of the `Request`, with managed transitions between states set when calling `resume()`, `suspend()`, or
/// `cancel()` on the `Request`.
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
}
}
}
// MARK: - Initial State
/// `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?
// MARK: - Mutable State
/// Type encapsulating all mutable state that may need to be accessed from anything other than the `underlyingQueue`.
struct MutableState {
/// State of the `Request`.
var state: State = .initialized
/// `ProgressHandler` and `DispatchQueue` provided for upload progress callbacks.
var uploadProgressHandler: (handler: ProgressHandler, queue: DispatchQueue)?
/// `ProgressHandler` and `DispatchQueue` provided for download progress callbacks.
var downloadProgressHandler: (handler: ProgressHandler, queue: DispatchQueue)?
/// `RedirectHandler` provided for to handle request redirection.
var redirectHandler: RedirectHandler?
/// `CachedResponseHandler` provided to handle response caching.
var cachedResponseHandler: CachedResponseHandler?
/// Closure called when the `Request` is able to create a cURL description of itself.
var cURLHandler: ((String) -> Void)?
/// Response serialization closures that handle response parsing.
var responseSerializers: [() -> Void] = []
/// Response serialization completion closures executed once all response serializers are complete.
var responseSerializerCompletions: [() -> Void] = []
/// Whether response serializer processing is finished.
var responseSerializerProcessingFinished = false
/// `URLCredential` used for authentication challenges.
var credential: URLCredential?
/// All `URLRequest`s created by Alamofire on behalf of the `Request`.
var requests: [URLRequest] = []
/// All `URLSessionTask`s created by Alamofire on behalf of the `Request`.
var tasks: [URLSessionTask] = []
/// All `URLSessionTaskMetrics` values gathered by Alamofire on behalf of the `Request`. Should correspond
/// exactly the the `tasks` created.
var metrics: [URLSessionTaskMetrics] = []
/// Number of times any retriers provided retried the `Request`.
var retryCount = 0
/// Final `AFError` for the `Request`, whether from various internal Alamofire calls or as a result of a `task`.
var error: AFError?
/// Whether the instance has had `finish()` called and is running the serializers. Should be replaced with a
/// representation in the state machine in the future.
var isFinishing = false
}
/// Protected `MutableState` value that provides thread-safe access to state values.
@Protected
fileprivate var mutableState = MutableState()
/// `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 }
// MARK: Progress
/// Closure type executed when monitoring the upload or download progress of a request.
public typealias ProgressHandler = (Progress) -> Void
/// `Progress` of the upload of the body of the executed `URLRequest`. Reset to `0` if the `Request` is retried.
public let uploadProgress = Progress(totalUnitCount: 0)
/// `Progress` of the download of any response data. Reset to `0` if the `Request` is retried.
public let downloadProgress = Progress(totalUnitCount: 0)
/// `ProgressHandler` called when `uploadProgress` is updated, on the provided `DispatchQueue`.
fileprivate var uploadProgressHandler: (handler: ProgressHandler, queue: DispatchQueue)? {
get { mutableState.uploadProgressHandler }
set { mutableState.uploadProgressHandler = newValue }
}
/// `ProgressHandler` called when `downloadProgress` is updated, on the provided `DispatchQueue`.
fileprivate var downloadProgressHandler: (handler: ProgressHandler, queue: DispatchQueue)? {
get { mutableState.downloadProgressHandler }
set { mutableState.downloadProgressHandler = newValue }
}
// MARK: Redirect Handling
/// `RedirectHandler` set on the instance.
public private(set) var redirectHandler: RedirectHandler? {
get { mutableState.redirectHandler }
set { mutableState.redirectHandler = newValue }
}
// MARK: Cached Response Handling
/// `CachedResponseHandler` set on the instance.
public private(set) var cachedResponseHandler: CachedResponseHandler? {
get { mutableState.cachedResponseHandler }
set { mutableState.cachedResponseHandler = newValue }
}
// MARK: URLCredential
/// `URLCredential` used for authentication challenges. Created by calling one of the `authenticate` methods.
public private(set) var credential: URLCredential? {
get { mutableState.credential }
set { mutableState.credential = newValue }
}
// MARK: Validators
/// `Validator` callback closures that store the validation calls enqueued.
@Protected
fileprivate var validators: [() -> Void] = []
// MARK: URLRequests
/// 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 { $0.currentRequest } } }
// MARK: HTTPURLResponse
/// `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 }
// MARK: Tasks
/// All `URLSessionTask`s created on behalf of the `Request`.
public var tasks: [URLSessionTask] { mutableState.tasks }
/// First `URLSessionTask` created on behalf of the `Request`.
public var firstTask: URLSessionTask? { tasks.first }
/// Last `URLSessionTask` crated on behalf of the `Request`.
public var lastTask: URLSessionTask? { tasks.last }
/// Current `URLSessionTask` created on behalf of the `Request`.
public var task: URLSessionTask? { lastTask }
// MARK: Metrics
/// All `URLSessionTaskMetrics` gathered on behalf of the `Request`. Should correspond to the `tasks` created.
public var allMetrics: [URLSessionTaskMetrics] { mutableState.metrics }
/// First `URLSessionTaskMetrics` gathered on behalf of the `Request`.
public var firstMetrics: URLSessionTaskMetrics? { allMetrics.first }
/// Last `URLSessionTaskMetrics` gathered on behalf of the `Request`.
public var lastMetrics: URLSessionTaskMetrics? { allMetrics.last }
/// Current `URLSessionTaskMetrics` gathered on behalf of the `Request`.
public var metrics: URLSessionTaskMetrics? { lastMetrics }
// MARK: Retry Count
/// Number of times the `Request` has been retried.
public var retryCount: Int { mutableState.retryCount }
// MARK: Error
/// `Error` returned from Alamofire internally, from the network request directly, or any validators executed.
public fileprivate(set) var error: AFError? {
get { mutableState.error }
set { mutableState.error = newValue }
}
/// Default initializer for the `Request` superclass.
///
/// - Parameters:
/// - id: `UUID` used for the `Hashable` and `Equatable` implementations. `UUID()` by default.
/// - underlyingQueue: `DispatchQueue` on which all internal `Request` work is performed.
/// - serializationQueue: `DispatchQueue` on which all serialization work is performed. By default targets
/// `underlyingQueue`, but can be passed another queue from a `Session`.
/// - eventMonitor: `EventMonitor` called for event callbacks from internal `Request` actions.
/// - interceptor: `RequestInterceptor` used throughout the request lifecycle.
/// - delegate: `RequestDelegate` that provides an interface to actions not performed by the `Request`.
init(id: UUID = UUID(),
underlyingQueue: DispatchQueue,
serializationQueue: DispatchQueue,
eventMonitor: EventMonitor?,
interceptor: RequestInterceptor?,
delegate: RequestDelegate) {
self.id = id
self.underlyingQueue = underlyingQueue
self.serializationQueue = serializationQueue
self.eventMonitor = eventMonitor
self.interceptor = interceptor
self.delegate = delegate
}
// MARK: - Internal Event API
// All API must be called from underlyingQueue.
/// Called when an initial `URLRequest` has been created on behalf of the instance. If a `RequestAdapter` is active,
/// the `URLRequest` will be adapted before being issued.
///
/// - Parameter request: The `URLRequest` created.
func didCreateInitialURLRequest(_ request: URLRequest) {
dispatchPrecondition(condition: .onQueue(underlyingQueue))
$mutableState.write { $0.requests.append(request) }
eventMonitor?.request(self, didCreateInitialURLRequest: request)
}
/// Called when initial `URLRequest` creation has failed, typically through a `URLRequestConvertible`.
///
/// - Note: Triggers retry.
///
/// - Parameter error: `AFError` thrown from the failed creation.
func didFailToCreateURLRequest(with error: AFError) {
dispatchPrecondition(condition: .onQueue(underlyingQueue))
self.error = error
eventMonitor?.request(self, didFailToCreateURLRequestWithError: error)
callCURLHandlerIfNecessary()
retryOrFinish(error: error)
}
/// Called when a `RequestAdapter` has successfully adapted a `URLRequest`.
///
/// - Parameters:
/// - initialRequest: The `URLRequest` that was adapted.
/// - adaptedRequest: The `URLRequest` returned by the `RequestAdapter`.
func didAdaptInitialRequest(_ initialRequest: URLRequest, to adaptedRequest: URLRequest) {
dispatchPrecondition(condition: .onQueue(underlyingQueue))
$mutableState.write { $0.requests.append(adaptedRequest) }
eventMonitor?.request(self, didAdaptInitialRequest: initialRequest, to: adaptedRequest)
}
/// Called when a `RequestAdapter` fails to adapt a `URLRequest`.
///
/// - Note: Triggers retry.
///
/// - Parameters:
/// - request: The `URLRequest` the adapter was called with.
/// - error: The `AFError` returned by the `RequestAdapter`.
func didFailToAdaptURLRequest(_ request: URLRequest, withError error: AFError) {
dispatchPrecondition(condition: .onQueue(underlyingQueue))
self.error = error
eventMonitor?.request(self, didFailToAdaptURLRequest: request, withError: error)
callCURLHandlerIfNecessary()
retryOrFinish(error: error)
}
/// Final `URLRequest` has been created for the instance.
///
/// - Parameter request: The `URLRequest` created.
func didCreateURLRequest(_ request: URLRequest) {
dispatchPrecondition(condition: .onQueue(underlyingQueue))
eventMonitor?.request(self, didCreateURLRequest: request)
callCURLHandlerIfNecessary()
}
/// Asynchronously calls any stored `cURLHandler` and then removes it from `mutableState`.
private func callCURLHandlerIfNecessary() {
$mutableState.write { mutableState in
guard let cURLHandler = mutableState.cURLHandler else { return }
self.underlyingQueue.async { cURLHandler(self.cURLDescription()) }
mutableState.cURLHandler = nil
}
}
/// Called when a `URLSessionTask` is created on behalf of the instance.
///
/// - Parameter task: The `URLSessionTask` created.
func didCreateTask(_ task: URLSessionTask) {
dispatchPrecondition(condition: .onQueue(underlyingQueue))
$mutableState.write { $0.tasks.append(task) }
eventMonitor?.request(self, didCreateTask: task)
}
/// Called when resumption is completed.
func didResume() {
dispatchPrecondition(condition: .onQueue(underlyingQueue))
eventMonitor?.requestDidResume(self)
}
/// Called when a `URLSessionTask` is resumed on behalf of the instance.
///
/// - Parameter task: The `URLSessionTask` resumed.
func didResumeTask(_ task: URLSessionTask) {
dispatchPrecondition(condition: .onQueue(underlyingQueue))
eventMonitor?.request(self, didResumeTask: task)
}
/// Called when suspension is completed.
func didSuspend() {
dispatchPrecondition(condition: .onQueue(underlyingQueue))
eventMonitor?.requestDidSuspend(self)
}
/// Called when a `URLSessionTask` is suspended on behalf of the instance.
///
/// - Parameter task: The `URLSessionTask` suspended.
func didSuspendTask(_ task: URLSessionTask) {
dispatchPrecondition(condition: .onQueue(underlyingQueue))
eventMonitor?.request(self, didSuspendTask: task)
}
/// Called when cancellation is completed, sets `error` to `AFError.explicitlyCancelled`.
func didCancel() {
dispatchPrecondition(condition: .onQueue(underlyingQueue))
error = error ?? AFError.explicitlyCancelled
eventMonitor?.requestDidCancel(self)
}
/// Called when a `URLSessionTask` is cancelled on behalf of the instance.
///
/// - Parameter task: The `URLSessionTask` cancelled.
func didCancelTask(_ task: URLSessionTask) {
dispatchPrecondition(condition: .onQueue(underlyingQueue))
eventMonitor?.request(self, didCancelTask: task)
}
/// Called when a `URLSessionTaskMetrics` value is gathered on behalf of the instance.
///
/// - Parameter metrics: The `URLSessionTaskMetrics` gathered.
func didGatherMetrics(_ metrics: URLSessionTaskMetrics) {
dispatchPrecondition(condition: .onQueue(underlyingQueue))
$mutableState.write { $0.metrics.append(metrics) }
eventMonitor?.request(self, didGatherMetrics: metrics)
}
/// Called when a `URLSessionTask` fails before it is finished, typically during certificate pinning.
///
/// - Parameters:
/// - task: The `URLSessionTask` which failed.
/// - error: The early failure `AFError`.
func didFailTask(_ task: URLSessionTask, earlyWithError error: AFError) {
dispatchPrecondition(condition: .onQueue(underlyingQueue))
self.error = error
// Task will still complete, so didCompleteTask(_:with:) will handle retry.
eventMonitor?.request(self, didFailTask: task, earlyWithError: error)
}
/// Called when a `URLSessionTask` completes. All tasks will eventually call this method.
///
/// - Note: Response validation is synchronously triggered in this step.
///
/// - Parameters:
/// - task: The `URLSessionTask` which completed.
/// - error: The `AFError` `task` may have completed with. If `error` has already been set on the instance, this
/// value is ignored.
func didCompleteTask(_ task: URLSessionTask, with error: AFError?) {
dispatchPrecondition(condition: .onQueue(underlyingQueue))
self.error = self.error ?? error
validators.forEach { $0() }
eventMonitor?.request(self, didCompleteTask: task, with: error)
retryOrFinish(error: self.error)
}
/// Called when the `RequestDelegate` is going to retry this `Request`. Calls `reset()`.
func prepareForRetry() {
dispatchPrecondition(condition: .onQueue(underlyingQueue))
$mutableState.write { $0.retryCount += 1 }
reset()
eventMonitor?.requestIsRetrying(self)
}
/// Called to determine whether retry will be triggered for the particular error, or whether the instance should
/// call `finish()`.
///
/// - Parameter error: The possible `AFError` which may trigger retry.
func retryOrFinish(error: AFError?) {
dispatchPrecondition(condition: .onQueue(underlyingQueue))
guard let error = error, let delegate = delegate else { finish(); return }
delegate.retryResult(for: self, dueTo: error) { retryResult in
switch retryResult {
case .doNotRetry:
self.finish()
case let .doNotRetryWithError(retryError):
self.finish(error: retryError.asAFError(orFailWith: "Received retryError was not already AFError"))
case .retry, .retryWithDelay:
delegate.retryRequest(self, withDelay: retryResult.delay)
}
}
}
/// Finishes this `Request` and starts the response serializers.
///
/// - Parameter error: The possible `Error` with which the instance will finish.
func finish(error: AFError? = nil) {
dispatchPrecondition(condition: .onQueue(underlyingQueue))
guard !mutableState.isFinishing else { return }
mutableState.isFinishing = true
if let error = error { self.error = error }
// Start response handlers
processNextResponseSerializer()
eventMonitor?.requestDidFinish(self)
}
/// Appends the response serialization closure to the instance.
///
/// - Note: This method will also `resume` the instance if `delegate.startImmediately` returns `true`.
///
/// - Parameter closure: The closure containing the response serialization call.
func appendResponseSerializer(_ closure: @escaping () -> Void) {
$mutableState.write { mutableState in
mutableState.responseSerializers.append(closure)
if mutableState.state == .finished {
mutableState.state = .resumed
}
if mutableState.responseSerializerProcessingFinished {
underlyingQueue.async { self.processNextResponseSerializer() }
}
if mutableState.state.canTransitionTo(.resumed) {
underlyingQueue.async { if self.delegate?.startImmediately == true { self.resume() } }
}
}
}
/// Returns the next response serializer closure to execute if there's one left.
///
/// - Returns: The next response serialization closure, if there is one.
func nextResponseSerializer() -> (() -> Void)? {
var responseSerializer: (() -> Void)?
$mutableState.write { mutableState in
let responseSerializerIndex = mutableState.responseSerializerCompletions.count
if responseSerializerIndex < mutableState.responseSerializers.count {
responseSerializer = mutableState.responseSerializers[responseSerializerIndex]
}
}
return responseSerializer
}
/// Processes the next response serializer and calls all completions if response serialization is complete.
func processNextResponseSerializer() {
guard let responseSerializer = nextResponseSerializer() else {
// Execute all response serializer completions and clear them
var completions: [() -> Void] = []
$mutableState.write { mutableState in
completions = mutableState.responseSerializerCompletions
// Clear out all response serializers and response serializer completions in mutable state since the
// request is complete. It's important to do this prior to calling the completion closures in case
// the completions call back into the request triggering a re-processing of the response serializers.
// An example of how this can happen is by calling cancel inside a response completion closure.
mutableState.responseSerializers.removeAll()
mutableState.responseSerializerCompletions.removeAll()
if mutableState.state.canTransitionTo(.finished) {
mutableState.state = .finished
}
mutableState.responseSerializerProcessingFinished = true
mutableState.isFinishing = false
}
completions.forEach { $0() }
// Cleanup the request
cleanup()
return
}
serializationQueue.async { responseSerializer() }
}
/// Notifies the `Request` that the response serializer is complete.
///
/// - Parameter completion: The completion handler provided with the response serializer, called when all serializers
/// are complete.
func responseSerializerDidComplete(completion: @escaping () -> Void) {
$mutableState.write { $0.responseSerializerCompletions.append(completion) }
processNextResponseSerializer()
}
/// Resets all task and response serializer related state for retry.
func reset() {
error = nil
uploadProgress.totalUnitCount = 0
uploadProgress.completedUnitCount = 0
downloadProgress.totalUnitCount = 0
downloadProgress.completedUnitCount = 0
$mutableState.write { state in
state.isFinishing = false
state.responseSerializerCompletions = []
}
}
/// Called when updating the upload progress.
///
/// - Parameters:
/// - totalBytesSent: Total bytes sent so far.
/// - totalBytesExpectedToSend: Total bytes expected to send.
func updateUploadProgress(totalBytesSent: Int64, totalBytesExpectedToSend: Int64) {
uploadProgress.totalUnitCount = totalBytesExpectedToSend
uploadProgress.completedUnitCount = totalBytesSent
uploadProgressHandler?.queue.async { self.uploadProgressHandler?.handler(self.uploadProgress) }
}
/// Perform a closure on the current `state` while locked.
///
/// - Parameter perform: The closure to perform.
func withState(perform: (State) -> Void) {
$mutableState.withState(perform: perform)
}
// MARK: Task Creation
/// Called when creating a `URLSessionTask` for this `Request`. Subclasses must override.
///
/// - Parameters:
/// - request: `URLRequest` to use to create the `URLSessionTask`.
/// - session: `URLSession` which creates the `URLSessionTask`.
///
/// - Returns: The `URLSessionTask` created.
func task(for request: URLRequest, using session: URLSession) -> URLSessionTask {
fatalError("Subclasses must override.")
}
// MARK: - Public API
// These APIs are callable from any queue.
// MARK: State
/// Cancels the instance. Once cancelled, a `Request` can no longer be resumed or suspended.
///
/// - Returns: The instance.
@discardableResult
public func cancel() -> Self {
$mutableState.write { mutableState in
guard mutableState.state.canTransitionTo(.cancelled) else { return }
mutableState.state = .cancelled
underlyingQueue.async { self.didCancel() }
guard let task = mutableState.tasks.last, task.state != .completed else {
underlyingQueue.async { self.finish() }
return
}
// Resume to ensure metrics are gathered.
task.resume()
task.cancel()
underlyingQueue.async { self.didCancelTask(task) }
}
return self
}
/// Suspends the instance.
///
/// - Returns: The instance.
@discardableResult
public func suspend() -> Self {
$mutableState.write { mutableState in
guard mutableState.state.canTransitionTo(.suspended) else { return }
mutableState.state = .suspended
underlyingQueue.async { self.didSuspend() }
guard let task = mutableState.tasks.last, task.state != .completed else { return }
task.suspend()
underlyingQueue.async { self.didSuspendTask(task) }
}
return self
}
/// Resumes the instance.
///
/// - Returns: The instance.
@discardableResult
public func resume() -> Self {
$mutableState.write { mutableState in
guard mutableState.state.canTransitionTo(.resumed) else { return }
mutableState.state = .resumed
underlyingQueue.async { self.didResume() }
guard let task = mutableState.tasks.last, task.state != .completed else { return }
task.resume()
underlyingQueue.async { self.didResumeTask(task) }
}
return self
}
// MARK: - Closure API
/// Associates a credential using the provided values with the instance.
///
/// - Parameters:
/// - username: The username.
/// - password: The password.
/// - persistence: The `URLCredential.Persistence` for the created `URLCredential`. `.forSession` by default.
///
/// - Returns: The instance.
@discardableResult
public func authenticate(username: String, password: String, persistence: URLCredential.Persistence = .forSession) -> Self {
let credential = URLCredential(user: username, password: password, persistence: persistence)
return authenticate(with: credential)
}
/// Associates the provided credential with the instance.
///
/// - Parameter credential: The `URLCredential`.
///
/// - Returns: The instance.
@discardableResult
public func authenticate(with credential: URLCredential) -> Self {
mutableState.credential = credential
return self
}
/// Sets a closure to be called periodically during the lifecycle of the instance as data is read from the server.
///
/// - Note: Only the last closure provided is used.
///
/// - Parameters:
/// - queue: The `DispatchQueue` to execute the closure on. `.main` by default.
/// - closure: The closure to be executed periodically as data is read from the server.
///
/// - Returns: The instance.
@discardableResult
public func downloadProgress(queue: DispatchQueue = .main, closure: @escaping ProgressHandler) -> Self {
mutableState.downloadProgressHandler = (handler: closure, queue: queue)
return self
}
/// Sets a closure to be called periodically during the lifecycle of the instance as data is sent to the server.
///
/// - Note: Only the last closure provided is used.
///
/// - Parameters:
/// - queue: The `DispatchQueue` to execute the closure on. `.main` by default.
/// - closure: The closure to be executed periodically as data is sent to the server.
///
/// - Returns: The instance.
@discardableResult
public func uploadProgress(queue: DispatchQueue = .main, closure: @escaping ProgressHandler) -> Self {
mutableState.uploadProgressHandler = (handler: closure, queue: queue)
return self
}
// MARK: Redirects
/// Sets the redirect handler for the instance which will be used if a redirect response is encountered.
///
/// - Note: Attempting to set the redirect handler more than once is a logic error and will crash.
///
/// - Parameter handler: The `RedirectHandler`.
///
/// - Returns: The instance.
@discardableResult
public func redirect(using handler: RedirectHandler) -> Self {
$mutableState.write { mutableState in
precondition(mutableState.redirectHandler == nil, "Redirect handler has already been set.")
mutableState.redirectHandler = handler
}
return self
}
// MARK: Cached Responses
/// Sets the cached response handler for the `Request` which will be used when attempting to cache a response.
///
/// - Note: Attempting to set the cache handler more than once is a logic error and will crash.
///
/// - Parameter handler: The `CachedResponseHandler`.
///
/// - Returns: The instance.
@discardableResult
public func cacheResponse(using handler: CachedResponseHandler) -> Self {
$mutableState.write { mutableState in
precondition(mutableState.cachedResponseHandler == nil, "Cached response handler has already been set.")
mutableState.cachedResponseHandler = handler
}
return self
}
/// Sets a handler to be called when the cURL description of the request is available.
///
/// - Note: When waiting for a `Request`'s `URLRequest` to be created, only the last `handler` will be called.
///
/// - Parameter handler: Closure to be called when the cURL description is available.
///
/// - Returns: The instance.
@discardableResult
public func cURLDescription(calling handler: @escaping (String) -> Void) -> Self {
$mutableState.write { mutableState in
if mutableState.requests.last != nil {
underlyingQueue.async { handler(self.cURLDescription()) }
} else {
mutableState.cURLHandler = handler
}
}
return self
}
// MARK: Cleanup
/// Final cleanup step executed when the instance finishes response serialization.
func cleanup() {
delegate?.cleanup(after: self)
// No-op: override in subclass
}
}
// MARK: - Protocol Conformances
extension Request: Equatable {
public static func ==(lhs: Request, rhs: Request) -> Bool {
lhs.id == rhs.id
}
}
extension Request: Hashable {
public func hash(into hasher: inout Hasher) {
hasher.combine(id)
}
}
extension Request: CustomStringConvertible {
/// A textual representation of this instance, including the `HTTPMethod` and `URL` if the `URLRequest` has been
/// created, as well as the response status code, if a response has been received.
public var description: String {
guard let request = performedRequests.last ?? lastRequest,
let url = request.url,
let method = request.httpMethod else { return "No request created yet." }
let requestDescription = "\(method) \(url.absoluteString)"
return response.map { "\(requestDescription) (\($0.statusCode))" } ?? requestDescription
}
}
extension Request {
/// cURL representation of the instance.
///
/// - Returns: The cURL equivalent of the instance.
public func cURLDescription() -> String {
guard
let request = lastRequest,
let url = request.url,
let host = url.host,
let method = request.httpMethod else { return "$ curl command could not be created" }
var components = ["$ curl -v"]
components.append("-X \(method)")
if let credentialStorage = delegate?.sessionConfiguration.urlCredentialStorage {
let protectionSpace = URLProtectionSpace(host: host,
port: url.port ?? 0,
protocol: url.scheme,
realm: host,
authenticationMethod: NSURLAuthenticationMethodHTTPBasic)
if let credentials = credentialStorage.credentials(for: protectionSpace)?.values {
for credential in credentials {
guard let user = credential.user, let password = credential.password else { continue }
components.append("-u \(user):\(password)")
}
} else {
if let credential = credential, let user = credential.user, let password = credential.password {
components.append("-u \(user):\(password)")
}
}
}
if let configuration = delegate?.sessionConfiguration, configuration.httpShouldSetCookies {
if
let cookieStorage = configuration.httpCookieStorage,
let cookies = cookieStorage.cookies(for: url), !cookies.isEmpty {
let allCookies = cookies.map { "\($0.name)=\($0.value)" }.joined(separator: ";")
components.append("-b \"\(allCookies)\"")
}
}
var headers = HTTPHeaders()
if let sessionHeaders = delegate?.sessionConfiguration.headers {
for header in sessionHeaders where header.name != "Cookie" {
headers[header.name] = header.value
}
}
for header in request.headers where header.name != "Cookie" {
headers[header.name] = header.value
}
for header in headers {
let escapedValue = header.value.replacingOccurrences(of: "\"", with: "\\\"")
components.append("-H \"\(header.name): \(escapedValue)\"")
}
if let httpBodyData = request.httpBody {
let httpBody = String(decoding: httpBodyData, as: UTF8.self)
var escapedBody = httpBody.replacingOccurrences(of: "\\\"", with: "\\\\\"")
escapedBody = escapedBody.replacingOccurrences(of: "\"", with: "\\\"")
components.append("-d \"\(escapedBody)\"")
}
components.append("\"\(url.absoluteString)\"")
return components.joined(separator: " \\\n\t")
}
}
/// Protocol abstraction for `Request`'s communication back to the `SessionDelegate`.
public protocol RequestDelegate: AnyObject {
/// `URLSessionConfiguration` used to create the underlying `URLSessionTask`s.
var sessionConfiguration: URLSessionConfiguration { get }
/// Determines whether the `Request` should automatically call `resume()` when adding the first response handler.
var startImmediately: Bool { get }
/// Notifies the delegate the `Request` has reached a point where it needs cleanup.
///
/// - Parameter request: The `Request` to cleanup after.
func cleanup(after request: Request)
/// Asynchronously ask the delegate whether a `Request` will be retried.
///
/// - Parameters:
/// - request: `Request` which failed.
/// - error: `Error` which produced the failure.
/// - completion: Closure taking the `RetryResult` for evaluation.
func retryResult(for request: Request, dueTo error: AFError, completion: @escaping (RetryResult) -> Void)
/// Asynchronously retry the `Request`.
///
/// - Parameters:
/// - request: `Request` which will be retried.
/// - timeDelay: `TimeInterval` after which the retry will be triggered.
func retryRequest(_ request: Request, withDelay timeDelay: TimeInterval?)
}
// MARK: - Subclasses
// MARK: - DataRequest
/// `Request` subclass which handles in-memory `Data` download using `URLSessionDataTask`.
public class DataRequest: Request {
/// `URLRequestConvertible` value used to create `URLRequest`s for this instance.
public let convertible: URLRequestConvertible
/// `Data` read from the server so far.
public var data: Data? { mutableData }
/// Protected storage for the `Data` read by the instance.
@Protected
private var mutableData: Data? = nil
/// Creates a `DataRequest` using the provided parameters.
///
/// - Parameters:
/// - id: `UUID` used for the `Hashable` and `Equatable` implementations. `UUID()` by default.
/// - convertible: `URLRequestConvertible` value used to create `URLRequest`s for this instance.
/// - underlyingQueue: `DispatchQueue` on which all internal `Request` work is performed.
/// - serializationQueue: `DispatchQueue` on which all serialization work is performed. By default targets
/// `underlyingQueue`, but can be passed another queue from a `Session`.
/// - eventMonitor: `EventMonitor` called for event callbacks from internal `Request` actions.
/// - interceptor: `RequestInterceptor` used throughout the request lifecycle.
/// - delegate: `RequestDelegate` that provides an interface to actions not performed by the `Request`.
init(id: UUID = UUID(),
convertible: URLRequestConvertible,
underlyingQueue: DispatchQueue,
serializationQueue: DispatchQueue,
eventMonitor: EventMonitor?,
interceptor: RequestInterceptor?,
delegate: RequestDelegate) {
self.convertible = convertible
super.init(id: id,
underlyingQueue: underlyingQueue,
serializationQueue: serializationQueue,
eventMonitor: eventMonitor,
interceptor: interceptor,
delegate: delegate)
}
override func reset() {
super.reset()
mutableData = nil
}
/// Called when `Data` is received by this instance.
///
/// - Note: Also calls `updateDownloadProgress`.
///
/// - Parameter data: The `Data` received.
func didReceive(data: Data) {
if self.data == nil {
mutableData = data
} else {
$mutableData.write { $0?.append(data) }
}
updateDownloadProgress()
}
override func task(for request: URLRequest, using session: URLSession) -> URLSessionTask {
let copiedRequest = request
return session.dataTask(with: copiedRequest)
}
/// Called to updated the `downloadProgress` of the instance.
func updateDownloadProgress() {
let totalBytesReceived = Int64(data?.count ?? 0)
let totalBytesExpected = task?.response?.expectedContentLength ?? NSURLSessionTransferSizeUnknown
downloadProgress.totalUnitCount = totalBytesExpected
downloadProgress.completedUnitCount = totalBytesReceived
downloadProgressHandler?.queue.async { self.downloadProgressHandler?.handler(self.downloadProgress) }
}
/// Validates the request, using the specified closure.
///
/// - Note: If validation fails, subsequent calls to response handlers will have an associated error.
///
/// - Parameter validation: `Validation` closure used to validate the response.
///
/// - Returns: The instance.
@discardableResult
public func validate(_ validation: @escaping Validation) -> Self {
let validator: () -> Void = { [unowned self] in
guard self.error == nil, let response = self.response else { return }
let result = validation(self.request, response, self.data)
if case let .failure(error) = result { self.error = error.asAFError(or: .responseValidationFailed(reason: .customValidationFailed(error: error))) }
self.eventMonitor?.request(self,
didValidateRequest: self.request,
response: response,
data: self.data,
withResult: result)
}
$validators.write { $0.append(validator) }
return self
}
}
// MARK: - DataStreamRequest
/// `Request` subclass which streams HTTP response `Data` through a `Handler` closure.
public final class DataStreamRequest: Request {
/// Closure type handling `DataStreamRequest.Stream` values.
public typealias Handler<Success, Failure: Error> = (Stream<Success, Failure>) throws -> Void
/// Type encapsulating an `Event` as it flows through the stream, as well as a `CancellationToken` which can be used
/// to stop the stream at any time.
public struct Stream<Success, Failure: Error> {
/// Latest `Event` from the stream.
public let event: Event<Success, Failure>
/// Token used to cancel the stream.
public let token: CancellationToken
/// Cancel the ongoing stream by canceling the underlying `DataStreamRequest`.
public func cancel() {
token.cancel()
}
}
/// Type representing an event flowing through the stream. Contains either the `Result` of processing streamed
/// `Data` or the completion of the stream.
public enum Event<Success, Failure: Error> {
/// Output produced every time the instance receives additional `Data`. The associated value contains the
/// `Result` of processing the incoming `Data`.
case stream(Result<Success, Failure>)
/// Output produced when the instance has completed, whether due to stream end, cancellation, or an error.
/// Associated `Completion` value contains the final state.
case complete(Completion)
}
/// Value containing the state of a `DataStreamRequest` when the stream was completed.
public struct Completion {
/// Last `URLRequest` issued by the instance.
public let request: URLRequest?
/// Last `HTTPURLResponse` received by the instance.
public let response: HTTPURLResponse?
/// Last `URLSessionTaskMetrics` produced for the instance.
public let metrics: URLSessionTaskMetrics?
/// `AFError` produced for the instance, if any.
public let error: AFError?
}
/// Type used to cancel an ongoing stream.
public struct CancellationToken {
weak var request: DataStreamRequest?
init(_ request: DataStreamRequest) {
self.request = request
}
/// Cancel the ongoing stream by canceling the underlying `DataStreamRequest`.
public func cancel() {
request?.cancel()
}
}
/// `URLRequestConvertible` value used to create `URLRequest`s for this instance.
public let convertible: URLRequestConvertible
/// Whether or not the instance will be cancelled if stream parsing encounters an error.
public let automaticallyCancelOnStreamError: Bool
/// Internal mutable state specific to this type.
struct StreamMutableState {
/// `OutputStream` bound to the `InputStream` produced by `asInputStream`, if it has been called.
var outputStream: OutputStream?
/// Stream closures called as `Data` is received.
var streams: [(_ data: Data) -> Void] = []
/// Number of currently executing streams. Used to ensure completions are only fired after all streams are
/// enqueued.
var numberOfExecutingStreams = 0
/// Completion calls enqueued while streams are still executing.
var enqueuedCompletionEvents: [() -> Void] = []
}
@Protected
var streamMutableState = StreamMutableState()
/// Creates a `DataStreamRequest` using the provided parameters.
///
/// - Parameters:
/// - id: `UUID` used for the `Hashable` and `Equatable` implementations. `UUID()`
/// by default.
/// - convertible: `URLRequestConvertible` value used to create `URLRequest`s for this
/// instance.
/// - automaticallyCancelOnStreamError: `Bool` indicating whether the instance will be cancelled when an `Error`
/// is thrown while serializing stream `Data`.
/// - underlyingQueue: `DispatchQueue` on which all internal `Request` work is performed.
/// - serializationQueue: `DispatchQueue` on which all serialization work is performed. By default
/// targets
/// `underlyingQueue`, but can be passed another queue from a `Session`.
/// - eventMonitor: `EventMonitor` called for event callbacks from internal `Request` actions.
/// - interceptor: `RequestInterceptor` used throughout the request lifecycle.
/// - delegate: `RequestDelegate` that provides an interface to actions not performed by
/// the `Request`.
init(id: UUID = UUID(),
convertible: URLRequestConvertible,
automaticallyCancelOnStreamError: Bool,
underlyingQueue: DispatchQueue,
serializationQueue: DispatchQueue,
eventMonitor: EventMonitor?,
interceptor: RequestInterceptor?,
delegate: RequestDelegate) {
self.convertible = convertible
self.automaticallyCancelOnStreamError = automaticallyCancelOnStreamError
super.init(id: id,
underlyingQueue: underlyingQueue,
serializationQueue: serializationQueue,
eventMonitor: eventMonitor,
interceptor: interceptor,
delegate: delegate)
}
override func task(for request: URLRequest, using session: URLSession) -> URLSessionTask {
let copiedRequest = request
return session.dataTask(with: copiedRequest)
}
override func finish(error: AFError? = nil) {
$streamMutableState.write { state in
state.outputStream?.close()
}
super.finish(error: error)
}
func didReceive(data: Data) {
$streamMutableState.write { state in
if let stream = state.outputStream {
underlyingQueue.async {
var bytes = Array(data)
stream.write(&bytes, maxLength: bytes.count)
}
}
state.numberOfExecutingStreams += state.streams.count
let localState = state
underlyingQueue.async { localState.streams.forEach { $0(data) } }
}
}
/// Validates the `URLRequest` and `HTTPURLResponse` received for the instance using the provided `Validation` closure.
///
/// - Parameter validation: `Validation` closure used to validate the request and response.
///
/// - Returns: The `DataStreamRequest`.
@discardableResult
public func validate(_ validation: @escaping Validation) -> Self {
let validator: () -> Void = { [unowned self] in
guard self.error == nil, let response = self.response else { return }
let result = validation(self.request, response)
if case let .failure(error) = result {
self.error = error.asAFError(or: .responseValidationFailed(reason: .customValidationFailed(error: error)))
}
self.eventMonitor?.request(self,
didValidateRequest: self.request,
response: response,
withResult: result)
}
$validators.write { $0.append(validator) }
return self
}
/// Produces an `InputStream` that receives the `Data` received by the instance.
///
/// - Note: The `InputStream` produced by this method must have `open()` called before being able to read `Data`.
/// Additionally, this method will automatically call `resume()` on the instance, regardless of whether or
/// not the creating session has `startRequestsImmediately` set to `true`.
///
/// - Parameter bufferSize: Size, in bytes, of the buffer between the `OutputStream` and `InputStream`.
///
/// - Returns: The `InputStream` bound to the internal `OutboundStream`.
public func asInputStream(bufferSize: Int = 1024) -> InputStream? {
defer { resume() }
var inputStream: InputStream?
$streamMutableState.write { state in
Foundation.Stream.getBoundStreams(withBufferSize: bufferSize,
inputStream: &inputStream,
outputStream: &state.outputStream)
state.outputStream?.open()
}
return inputStream
}
func capturingError(from closure: () throws -> Void) {
do {
try closure()
} catch {
self.error = error.asAFError(or: .responseSerializationFailed(reason: .customSerializationFailed(error: error)))
cancel()
}
}
func appendStreamCompletion<Success, Failure>(on queue: DispatchQueue,
stream: @escaping Handler<Success, Failure>) {
appendResponseSerializer {
self.underlyingQueue.async {
self.responseSerializerDidComplete {
self.$streamMutableState.write { state in
guard state.numberOfExecutingStreams == 0 else {
state.enqueuedCompletionEvents.append {
self.enqueueCompletion(on: queue, stream: stream)
}
return
}
self.enqueueCompletion(on: queue, stream: stream)
}
}
}
}
}
func enqueueCompletion<Success, Failure>(on queue: DispatchQueue,
stream: @escaping Handler<Success, Failure>) {
queue.async {
do {
let completion = Completion(request: self.request,
response: self.response,
metrics: self.metrics,
error: self.error)
try stream(.init(event: .complete(completion), token: .init(self)))
} catch {
// Ignore error, as errors on Completion can't be handled anyway.
}
}
}
}
extension DataStreamRequest.Stream {
/// Incoming `Result` values from `Event.stream`.
public var result: Result<Success, Failure>? {
guard case let .stream(result) = event else { return nil }
return result
}
/// `Success` value of the instance, if any.
public var value: Success? {
guard case let .success(value) = result else { return nil }
return value
}
/// `Failure` value of the instance, if any.
public var error: Failure? {
guard case let .failure(error) = result else { return nil }
return error
}
/// `Completion` value of the instance, if any.
public var completion: DataStreamRequest.Completion? {
guard case let .complete(completion) = event else { return nil }
return completion
}
}
// MARK: - DownloadRequest
/// `Request` subclass which downloads `Data` to a file on disk using `URLSessionDownloadTask`.
public class DownloadRequest: Request {
/// A set of options to be executed prior to moving a downloaded file from the temporary `URL` to the destination
/// `URL`.
public struct Options: OptionSet {
/// Specifies that intermediate directories for the destination URL should be created.
public static let createIntermediateDirectories = Options(rawValue: 1 << 0)
/// Specifies that any previous file at the destination `URL` should be removed.
public static let removePreviousFile = Options(rawValue: 1 << 1)
public let rawValue: Int
public init(rawValue: Int) {
self.rawValue = rawValue
}
}
// MARK: Destination
/// A closure executed once a `DownloadRequest` has successfully completed in order to determine where to move the
/// temporary file written to during the download process. The closure takes two arguments: the temporary file URL
/// and the URL response, and returns a two arguments: the file URL where the temporary file should be moved and
/// the options defining how the file should be moved.
public typealias Destination = (_ temporaryURL: URL,
_ response: HTTPURLResponse) -> (destinationURL: URL, options: Options)
/// Creates a download file destination closure which uses the default file manager to move the temporary file to a
/// file URL in the first available directory with the specified search path directory and search path domain mask.
///
/// - Parameters:
/// - directory: The search path directory. `.documentDirectory` by default.
/// - domain: The search path domain mask. `.userDomainMask` by default.
/// - options: `DownloadRequest.Options` used when moving the downloaded file to its destination. None by
/// default.
/// - Returns: The `Destination` closure.
public class func suggestedDownloadDestination(for directory: FileManager.SearchPathDirectory = .documentDirectory,
in domain: FileManager.SearchPathDomainMask = .userDomainMask,
options: Options = []) -> Destination {
{ temporaryURL, response in
let directoryURLs = FileManager.default.urls(for: directory, in: domain)
let url = directoryURLs.first?.appendingPathComponent(response.suggestedFilename!) ?? temporaryURL
return (url, options)
}
}
/// Default `Destination` used by Alamofire to ensure all downloads persist. This `Destination` prepends
/// `Alamofire_` to the automatically generated download name and moves it within the temporary directory. Files
/// with this destination must be additionally moved if they should survive the system reclamation of temporary
/// space.
static let defaultDestination: Destination = { url, _ in
let filename = "Alamofire_\(url.lastPathComponent)"
let destination = url.deletingLastPathComponent().appendingPathComponent(filename)
return (destination, [])
}
// MARK: Downloadable
/// Type describing the source used to create the underlying `URLSessionDownloadTask`.
public enum Downloadable {
/// Download should be started from the `URLRequest` produced by the associated `URLRequestConvertible` value.
case request(URLRequestConvertible)
/// Download should be started from the associated resume `Data` value.
case resumeData(Data)
}
// MARK: Mutable State
/// Type containing all mutable state for `DownloadRequest` instances.
private struct DownloadRequestMutableState {
/// Possible resume `Data` produced when cancelling the instance.
var resumeData: Data?
/// `URL` to which `Data` is being downloaded.
var fileURL: URL?
}
/// Protected mutable state specific to `DownloadRequest`.
@Protected
private var mutableDownloadState = DownloadRequestMutableState()
/// If the download is resumable and eventually cancelled, this value may be used to resume the download using the
/// `download(resumingWith data:)` API.
///
/// - Note: For more information about `resumeData`, see [Apple's documentation](https://developer.apple.com/documentation/foundation/urlsessiondownloadtask/1411634-cancel).
public var resumeData: Data? { mutableDownloadState.resumeData }
/// If the download is successful, the `URL` where the file was downloaded.
public var fileURL: URL? { mutableDownloadState.fileURL }
// MARK: Initial State
/// `Downloadable` value used for this instance.
public let downloadable: Downloadable
/// The `Destination` to which the downloaded file is moved.
let destination: Destination
/// Creates a `DownloadRequest` using the provided parameters.
///
/// - Parameters:
/// - id: `UUID` used for the `Hashable` and `Equatable` implementations. `UUID()` by default.
/// - downloadable: `Downloadable` value used to create `URLSessionDownloadTasks` for the instance.
/// - underlyingQueue: `DispatchQueue` on which all internal `Request` work is performed.
/// - serializationQueue: `DispatchQueue` on which all serialization work is performed. By default targets
/// `underlyingQueue`, but can be passed another queue from a `Session`.
/// - eventMonitor: `EventMonitor` called for event callbacks from internal `Request` actions.
/// - interceptor: `RequestInterceptor` used throughout the request lifecycle.
/// - delegate: `RequestDelegate` that provides an interface to actions not performed by the `Request`
/// - destination: `Destination` closure used to move the downloaded file to its final location.
init(id: UUID = UUID(),
downloadable: Downloadable,
underlyingQueue: DispatchQueue,
serializationQueue: DispatchQueue,
eventMonitor: EventMonitor?,
interceptor: RequestInterceptor?,
delegate: RequestDelegate,
destination: @escaping Destination) {
self.downloadable = downloadable
self.destination = destination
super.init(id: id,
underlyingQueue: underlyingQueue,
serializationQueue: serializationQueue,
eventMonitor: eventMonitor,
interceptor: interceptor,
delegate: delegate)
}
override func reset() {
super.reset()
$mutableDownloadState.write {
$0.resumeData = nil
$0.fileURL = nil
}
}
/// Called when a download has finished.
///
/// - Parameters:
/// - task: `URLSessionTask` that finished the download.
/// - result: `Result` of the automatic move to `destination`.
func didFinishDownloading(using task: URLSessionTask, with result: Result<URL, AFError>) {
eventMonitor?.request(self, didFinishDownloadingUsing: task, with: result)
switch result {
case let .success(url): mutableDownloadState.fileURL = url
case let .failure(error): self.error = error
}
}
/// Updates the `downloadProgress` using the provided values.
///
/// - Parameters:
/// - bytesWritten: Total bytes written so far.
/// - totalBytesExpectedToWrite: Total bytes expected to write.
func updateDownloadProgress(bytesWritten: Int64, totalBytesExpectedToWrite: Int64) {
downloadProgress.totalUnitCount = totalBytesExpectedToWrite
downloadProgress.completedUnitCount += bytesWritten
downloadProgressHandler?.queue.async { self.downloadProgressHandler?.handler(self.downloadProgress) }
}
override func task(for request: URLRequest, using session: URLSession) -> URLSessionTask {
session.downloadTask(with: request)
}
/// Creates a `URLSessionTask` from the provided resume data.
///
/// - Parameters:
/// - data: `Data` used to resume the download.
/// - session: `URLSession` used to create the `URLSessionTask`.
///
/// - Returns: The `URLSessionTask` created.
public func task(forResumeData data: Data, using session: URLSession) -> URLSessionTask {
session.downloadTask(withResumeData: data)
}
/// Cancels the instance. Once cancelled, a `DownloadRequest` can no longer be resumed or suspended.
///
/// - Note: This method will NOT produce resume data. If you wish to cancel and produce resume data, use
/// `cancel(producingResumeData:)` or `cancel(byProducingResumeData:)`.
///
/// - Returns: The instance.
@discardableResult
override public func cancel() -> Self {
cancel(producingResumeData: false)
}
/// Cancels the instance, optionally producing resume data. Once cancelled, a `DownloadRequest` can no longer be
/// resumed or suspended.
///
/// - Note: If `producingResumeData` is `true`, the `resumeData` property will be populated with any resume data, if
/// available.
///
/// - Returns: The instance.
@discardableResult
public func cancel(producingResumeData shouldProduceResumeData: Bool) -> Self {
cancel(optionallyProducingResumeData: shouldProduceResumeData ? { _ in } : nil)
}
/// Cancels the instance while producing resume data. Once cancelled, a `DownloadRequest` can no longer be resumed
/// or suspended.
///
/// - Note: The resume data passed to the completion handler will also be available on the instance's `resumeData`
/// property.
///
/// - Parameter completionHandler: The completion handler that is called when the download has been successfully
/// cancelled. It is not guaranteed to be called on a particular queue, so you may
/// want use an appropriate queue to perform your work.
///
/// - Returns: The instance.
@discardableResult
public func cancel(byProducingResumeData completionHandler: @escaping (_ data: Data?) -> Void) -> Self {
cancel(optionallyProducingResumeData: completionHandler)
}
/// Internal implementation of cancellation that optionally takes a resume data handler. If no handler is passed,
/// cancellation is performed without producing resume data.
///
/// - Parameter completionHandler: Optional resume data handler.
///
/// - Returns: The instance.
private func cancel(optionallyProducingResumeData completionHandler: ((_ resumeData: Data?) -> Void)?) -> Self {
$mutableState.write { mutableState in
guard mutableState.state.canTransitionTo(.cancelled) else { return }
mutableState.state = .cancelled
underlyingQueue.async { self.didCancel() }
guard let task = mutableState.tasks.last as? URLSessionDownloadTask, task.state != .completed else {
underlyingQueue.async { self.finish() }
return
}
if let completionHandler = completionHandler {
// Resume to ensure metrics are gathered.
task.resume()
task.cancel { resumeData in
self.mutableDownloadState.resumeData = resumeData
self.underlyingQueue.async { self.didCancelTask(task) }
completionHandler(resumeData)
}
} else {
// Resume to ensure metrics are gathered.
task.resume()
task.cancel(byProducingResumeData: { _ in })
self.underlyingQueue.async { self.didCancelTask(task) }
}
}
return self
}
/// Validates the request, using the specified closure.
///
/// - Note: If validation fails, subsequent calls to response handlers will have an associated error.
///
/// - Parameter validation: `Validation` closure to validate the response.
///
/// - Returns: The instance.
@discardableResult
public func validate(_ validation: @escaping Validation) -> Self {
let validator: () -> Void = { [unowned self] in
guard self.error == nil, let response = self.response else { return }
let result = validation(self.request, response, self.fileURL)
if case let .failure(error) = result {
self.error = error.asAFError(or: .responseValidationFailed(reason: .customValidationFailed(error: error)))
}
self.eventMonitor?.request(self,
didValidateRequest: self.request,
response: response,
fileURL: self.fileURL,
withResult: result)
}
$validators.write { $0.append(validator) }
return self
}
}
// MARK: - UploadRequest
/// `DataRequest` subclass which handles `Data` upload from memory, file, or stream using `URLSessionUploadTask`.
public class UploadRequest: DataRequest {
/// Type describing the origin of the upload, whether `Data`, file, or stream.
public enum Uploadable {
/// Upload from the provided `Data` value.
case data(Data)
/// Upload from the provided file `URL`, as well as a `Bool` determining whether the source file should be
/// automatically removed once uploaded.
case file(URL, shouldRemove: Bool)
/// Upload from the provided `InputStream`.
case stream(InputStream)
}
// MARK: Initial State
/// The `UploadableConvertible` value used to produce the `Uploadable` value for this instance.
public let upload: UploadableConvertible
/// `FileManager` used to perform cleanup tasks, including the removal of multipart form encoded payloads written
/// to disk.
public let fileManager: FileManager
// MARK: Mutable State
/// `Uploadable` value used by the instance.
public var uploadable: Uploadable?
/// Creates an `UploadRequest` using the provided parameters.
///
/// - Parameters:
/// - id: `UUID` used for the `Hashable` and `Equatable` implementations. `UUID()` by default.
/// - convertible: `UploadConvertible` value used to determine the type of upload to be performed.
/// - underlyingQueue: `DispatchQueue` on which all internal `Request` work is performed.
/// - serializationQueue: `DispatchQueue` on which all serialization work is performed. By default targets
/// `underlyingQueue`, but can be passed another queue from a `Session`.
/// - eventMonitor: `EventMonitor` called for event callbacks from internal `Request` actions.
/// - interceptor: `RequestInterceptor` used throughout the request lifecycle.
/// - delegate: `RequestDelegate` that provides an interface to actions not performed by the `Request`.
init(id: UUID = UUID(),
convertible: UploadConvertible,
underlyingQueue: DispatchQueue,
serializationQueue: DispatchQueue,
eventMonitor: EventMonitor?,
interceptor: RequestInterceptor?,
fileManager: FileManager,
delegate: RequestDelegate) {
upload = convertible
self.fileManager = fileManager
super.init(id: id,
convertible: convertible,
underlyingQueue: underlyingQueue,
serializationQueue: serializationQueue,
eventMonitor: eventMonitor,
interceptor: interceptor,
delegate: delegate)
}
/// Called when the `Uploadable` value has been created from the `UploadConvertible`.
///
/// - Parameter uploadable: The `Uploadable` that was created.
func didCreateUploadable(_ uploadable: Uploadable) {
self.uploadable = uploadable
eventMonitor?.request(self, didCreateUploadable: uploadable)
}
/// Called when the `Uploadable` value could not be created.
///
/// - Parameter error: `AFError` produced by the failure.
func didFailToCreateUploadable(with error: AFError) {
self.error = error
eventMonitor?.request(self, didFailToCreateUploadableWithError: error)
retryOrFinish(error: error)
}
override func task(for request: URLRequest, using session: URLSession) -> URLSessionTask {
guard let uploadable = uploadable else {
fatalError("Attempting to create a URLSessionUploadTask when Uploadable value doesn't exist.")
}
switch uploadable {
case let .data(data): return session.uploadTask(with: request, from: data)
case let .file(url, _): return session.uploadTask(with: request, fromFile: url)
case .stream: return session.uploadTask(withStreamedRequest: request)
}
}
override func reset() {
// Uploadable must be recreated on every retry.
uploadable = nil
super.reset()
}
/// Produces the `InputStream` from `uploadable`, if it can.
///
/// - Note: Calling this method with a non-`.stream` `Uploadable` is a logic error and will crash.
///
/// - Returns: The `InputStream`.
func inputStream() -> InputStream {
guard let uploadable = uploadable else {
fatalError("Attempting to access the input stream but the uploadable doesn't exist.")
}
guard case let .stream(stream) = uploadable else {
fatalError("Attempted to access the stream of an UploadRequest that wasn't created with one.")
}
eventMonitor?.request(self, didProvideInputStream: stream)
return stream
}
override public func cleanup() {
defer { super.cleanup() }
guard
let uploadable = self.uploadable,
case let .file(url, shouldRemove) = uploadable,
shouldRemove
else { return }
try? fileManager.removeItem(at: url)
}
}
/// A type that can produce an `UploadRequest.Uploadable` value.
public protocol UploadableConvertible {
/// Produces an `UploadRequest.Uploadable` value from the instance.
///
/// - Returns: The `UploadRequest.Uploadable`.
/// - Throws: Any `Error` produced during creation.
func createUploadable() throws -> UploadRequest.Uploadable
}
extension UploadRequest.Uploadable: UploadableConvertible {
public func createUploadable() throws -> UploadRequest.Uploadable {
self
}
}
/// A type that can be converted to an upload, whether from an `UploadRequest.Uploadable` or `URLRequestConvertible`.
public protocol UploadConvertible: UploadableConvertible & URLRequestConvertible {}