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@kashiftriffort
Last active September 28, 2023 23:35
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URLSession swizzling in Swift
extension URLSessionConfiguration {
@objc
static func setupSwizzledSessionConfiguration() {
guard self == URLSessionConfiguration.self else {
return
}
let defaultSessionConfiguration = class_getClassMethod(URLSessionConfiguration.self, #selector(getter: URLSessionConfiguration.default))
let swizzledDefaultSessionConfiguration = class_getClassMethod(URLSessionConfiguration.self, #selector(URLSessionConfiguration.swizzledDefaultSessionConfiguration))
method_exchangeImplementations(defaultSessionConfiguration!, swizzledDefaultSessionConfiguration!)
let ephemeralSessionConfiguration = class_getClassMethod(URLSessionConfiguration.self, #selector(getter: URLSessionConfiguration.ephemeral))
let swizzledEphemeralSessionConfiguration = class_getClassMethod(URLSessionConfiguration.self, #selector(URLSessionConfiguration.swizzledEphemeralSessionConfiguration))
method_exchangeImplementations(ephemeralSessionConfiguration!, swizzledEphemeralSessionConfiguration!)
}
@objc class func swizzledDefaultSessionConfiguration() -> URLSessionConfiguration {
let configuration = swizzledDefaultSessionConfiguration()
configuration.protocolClasses?.insert(TempHTTPProtocol.self, at: 0)
URLProtocol.registerClass(TempHTTPProtocol.self)
return configuration
}
@objc class func swizzledEphemeralSessionConfiguration() -> URLSessionConfiguration {
let configuration = swizzledEphemeralSessionConfiguration()
configuration.protocolClasses?.insert(TempHTTPProtocol.self, at: 0)
URLProtocol.registerClass(TempHTTPProtocol.self)
return configuration
}
}
class TempHTTPProtocol: URLProtocol {
struct Constants {
static let RequestHandledKey = "TempProtocolRequestHandled"
}
var session: URLSession?
var sessionTask: URLSessionDataTask?
var currentRequest: TempDataAccessLayer?
override init(request: URLRequest, cachedResponse: CachedURLResponse?, client: URLProtocolClient?) {
super.init(request: request, cachedResponse: cachedResponse, client: client)
if session == nil {
session = URLSession(configuration: .default, delegate: self, delegateQueue: nil)
}
}
override public class func canInit(with request: URLRequest) -> Bool {
if TempHTTPProtocol.property(forKey: Constants.RequestHandledKey, in: request) != nil {
return false
}
return true
}
override public class func canonicalRequest(for request: URLRequest) -> URLRequest {
return request
}
override public func startLoading() {
guard let newRequest = ((request as NSURLRequest).mutableCopy() as? NSMutableURLRequest) else {
return
}
TempHTTPProtocol.setProperty(true, forKey: Constants.RequestHandledKey, in: newRequest)
sessionTask = session?.dataTask(with: newRequest as URLRequest)
sessionTask?.resume()
currentRequest = TempDataAccessLayer(request: newRequest)
}
override public func stopLoading() {
sessionTask?.cancel()
currentRequest?.httpBody = request.httpBodyStream?.readfully()
if let startDate = currentRequest?.date {
currentRequest?.duration = Double(Date().timeIntervalSince(startDate)) * 1000
}
DispatchQueue.main.async {
print(self.currentRequest?.url)
print(self.currentRequest?.headers)
print(self.currentRequest?.date)
print(self.currentRequest?.stausCode)
print(self.currentRequest?.duration)
print(self.currentRequest?.responseHeaders)
print(self.currentRequest?.errorDescription)
self.session?.invalidateAndCancel()
}
}
}
extension TempHTTPProtocol: URLSessionDataDelegate {
public func urlSession(_ session: URLSession, dataTask: URLSessionDataTask, didReceive data: Data) {
client?.urlProtocol(self, didLoad: data)
if currentRequest?.dataResponse == nil {
currentRequest?.dataResponse = data
} else {
currentRequest?.dataResponse?.append(data)
}
}
public func urlSession(_ session: URLSession, dataTask: URLSessionDataTask, didReceive response: URLResponse, completionHandler: @escaping (URLSession.ResponseDisposition) -> Void) {
let policy = URLCache.StoragePolicy(rawValue: request.cachePolicy.rawValue) ?? .notAllowed
client?.urlProtocol(self, didReceive: response, cacheStoragePolicy: policy)
currentRequest?.initResponse(response: response)
completionHandler(.allow)
}
public func urlSession(_ session: URLSession, task: URLSessionTask, didCompleteWithError error: Error?) {
if let error = error {
currentRequest?.errorDescription = error.localizedDescription
client?.urlProtocol(self, didFailWithError: error)
} else {
client?.urlProtocolDidFinishLoading(self)
}
}
public func urlSession(_ session: URLSession, task: URLSessionTask, willPerformHTTPRedirection response: HTTPURLResponse, newRequest request: URLRequest, completionHandler: @escaping (URLRequest?) -> Void) {
client?.urlProtocol(self, wasRedirectedTo: request, redirectResponse: response)
completionHandler(request)
}
public func urlSession(_ session: URLSession, didBecomeInvalidWithError error: Error?) {
guard let error = error else { return }
currentRequest?.errorDescription = error.localizedDescription
client?.urlProtocol(self, didFailWithError: error)
}
public func urlSession(_ session: URLSession, didReceive challenge: URLAuthenticationChallenge, completionHandler: @escaping (URLSession.AuthChallengeDisposition, URLCredential?) -> Void) {
let protectionSpace = challenge.protectionSpace
let sender = challenge.sender
if protectionSpace.authenticationMethod == NSURLAuthenticationMethodServerTrust {
if let serverTrust = protectionSpace.serverTrust {
let credential = URLCredential(trust: serverTrust)
sender?.use(credential, for: challenge)
completionHandler(.useCredential, credential)
return
}
}
if protectionSpace.authenticationMethod == NSURLAuthenticationMethodClientCertificate {
completionHandler(.performDefaultHandling, nil);
return
}
}
public func urlSessionDidFinishEvents(forBackgroundURLSession session: URLSession) {
client?.urlProtocolDidFinishLoading(self)
}
}
extension InputStream {
func readfully() -> Data {
var result = Data()
var buffer = [UInt8](repeating: 0, count: 10 * 1024 * 1024)
open()
var amount = 0
repeat {
amount = read(&buffer, maxLength: buffer.count)
if amount > 0 {
result.append(buffer, count: amount)
}
} while amount > 0
close()
return result
}
}
class TempDataAccessLayer: Codable {
let url: String
let date: Date
let method: String
var headers: [String: String]?
var httpBody: Data?
var stausCode: Int
var responseHeaders: [String: String]?
var dataResponse: Data?
var errorDescription: String?
var duration: Double?
init(request: NSURLRequest) {
url = request.url?.absoluteString ?? ""
date = Date()
method = request.httpMethod
headers = request.allHTTPHeaderFields
httpBody = request.httpBody
stausCode = 0
}
func initResponse(response: URLResponse) {
guard let responseHttp = response as? HTTPURLResponse else {return}
stausCode = responseHttp.statusCode
responseHeaders = responseHttp.allHeaderFields as? [String: String]
}
}
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