KCD/CustomHTTPProtocol.swift

   1 //
   2 //  CustomHTTPProtocol.swift
   3 //  KCD
   4 //
   5 //  Created by Hori,Masaki on 2017/02/10.
   6 //  Copyright © 2017年 Hori,Masaki. All rights reserved.
   7 //
   8
   9 import Cocoa
  10
  11
  12 protocol CustomHTTPProtocolDelegate: class {
  13     func customHTTPProtocol(_ proto: CustomHTTPProtocol, didRecieve response: URLResponse)
  14     func customHTTPProtocol(_ proto: CustomHTTPProtocol, didRecieve data: Data)
  15     func customHTTPProtocolDidFinishLoading(_ proto: CustomHTTPProtocol)
  16     func customHTTPProtocol(_ proto: CustomHTTPProtocol, didFailWithError error: Error)
  17 }
  18
  19 class CustomHTTPProtocol: URLProtocol {
  20     fileprivate static let requestProperty = "com.masakih.KCD.requestProperty"
  21     static var classDelegate: CustomHTTPProtocolDelegate?
  22     fileprivate static let cachedExtensions = ["swf", "flv", "png", "jpg", "jpeg", "mp3"]
  23     fileprivate static let cacheFileURL: URL = ApplicationDirecrories.support.appendingPathComponent("Caches")
  24     fileprivate static let kcdURLCache = URLCache(memoryCapacity: 32 * 1024 * 1024,
  25                                                   diskCapacity: 1024 * 1024 * 1024,
  26                                                   diskPath: cacheFileURL.path)
  27
  28     class func clearCache() { kcdURLCache.removeAllCachedResponses() }
  29     class func start() { URLProtocol.registerClass(CustomHTTPProtocol.self) }
  30
  31     override class func canInit(with request: URLRequest) -> Bool {
  32         if let _ = property(forKey: requestProperty, in: request) { return false }
  33         if let scheme = request.url?.scheme?.lowercased(),
  34             (scheme == "http" || scheme == "https") {
  35             return true
  36         }
  37         return false
  38     }
  39     override class func canonicalRequest(for request: URLRequest) -> URLRequest {
  40         return request
  41     }
  42
  43     fileprivate var delegate: CustomHTTPProtocolDelegate? { return CustomHTTPProtocol.classDelegate }
  44
  45     fileprivate var session: URLSession?
  46     fileprivate var dataTask: URLSessionDataTask?
  47     fileprivate var cachePolicy: URLCache.StoragePolicy = .notAllowed
  48     fileprivate var data: Data = Data()
  49     fileprivate var didRetry: Bool = false
  50     fileprivate var didRecieveData: Bool = false
  51
  52     private func use(_ cache: CachedURLResponse) {
  53         delegate?.customHTTPProtocol(self, didRecieve: cache.response)
  54         client?.urlProtocol(self, didReceive: cache.response, cacheStoragePolicy: .allowed)
  55
  56         delegate?.customHTTPProtocol(self, didRecieve: cache.data)
  57         client?.urlProtocol(self, didLoad: cache.data)
  58
  59         delegate?.customHTTPProtocolDidFinishLoading(self)
  60         client?.urlProtocolDidFinishLoading(self)
  61     }
  62     override func startLoading() {
  63         guard let newRequest = (request as NSObject).mutableCopy() as? NSMutableURLRequest
  64             else { fatalError("Can not convert to NSMutableURLRequest") }
  65         CustomHTTPProtocol.setProperty(true,
  66                                        forKey: CustomHTTPProtocol.requestProperty,
  67                                        in: newRequest)
  68
  69         if let cache = CustomHTTPProtocol.kcdURLCache.cachedResponse(for: request),
  70             let info = cache.userInfo,
  71             let expires = info["Expires"] as? Date,
  72             Date().compare(expires) == .orderedAscending {
  73             use(cache)
  74             if let name = request.url?.lastPathComponent {
  75                 Debug.print("Use cache for", name, level: .full)
  76             } else {
  77                 Debug.print("Use cache", level: .full)
  78             }
  79
  80             return
  81         }
  82
  83         let config = URLSessionConfiguration.default
  84         config.protocolClasses = [type(of: self)]
  85         session = URLSession(configuration: config, delegate: self, delegateQueue: nil)
  86         dataTask = session?.dataTask(with: newRequest as URLRequest)
  87         dataTask?.resume()
  88     }
  89     override func stopLoading() {
  90         dataTask?.cancel()
  91     }
  92 }
  93
  94 extension CustomHTTPProtocol: URLSessionDataDelegate {
  95     func urlSession(_ session: URLSession,
  96                     task: URLSessionTask,
  97                     willPerformHTTPRedirection response: HTTPURLResponse,
  98                     newRequest request: URLRequest,
  99                     completionHandler: @escaping (URLRequest?) -> Void) {
 100         Debug.print("willPerformHTTPRedirection", level: .full)
 101         client?.urlProtocol(self, wasRedirectedTo: request, redirectResponse: response)
 102         completionHandler(request)
 103     }
 104     func urlSession(_ session: URLSession,
 105                     dataTask: URLSessionDataTask,
 106                     didReceive response: URLResponse,
 107                     completionHandler: @escaping (URLSession.ResponseDisposition) -> Void) {
 108         Debug.print("didReceive response", level: .full)
 109
 110         if let response = response as? HTTPURLResponse,
 111             let request = dataTask.originalRequest {
 112             cachePolicy = CacheStoragePolicy(for: request, response: response)
 113         }
 114
 115         delegate?.customHTTPProtocol(self, didRecieve: response)
 116         client?.urlProtocol(self, didReceive: response, cacheStoragePolicy: cachePolicy)
 117         completionHandler(.allow)
 118     }
 119     func urlSession(_ session: URLSession, dataTask: URLSessionDataTask, didReceive data: Data) {
 120         Debug.print("didReceive data", level: .full)
 121         if cachePolicy == .allowed {
 122             self.data.append(data)
 123         }
 124         delegate?.customHTTPProtocol(self, didRecieve: data)
 125         client?.urlProtocol(self, didLoad: data)
 126         didRecieveData = true
 127     }
 128
 129     // cfurlErrorNetworkConnectionLost の場合はもう一度試す
 130     private func canRetry(error: NSError) -> Bool {
 131         guard error.code == Int(CFNetworkErrors.cfurlErrorNetworkConnectionLost.rawValue),
 132             !didRetry,
 133             !didRecieveData
 134             else { return false }
 135         print("Retry download...")
 136         return true
 137     }
 138     func urlSession(_ session: URLSession, task: URLSessionTask, didCompleteWithError error: Error?) {
 139         if let error = error {
 140             if canRetry(error: error as NSError),
 141                 let request = task.originalRequest {
 142                 didRetry = true
 143                 dataTask = session.dataTask(with: request)
 144                 dataTask?.resume()
 145                 return
 146             }
 147             Debug.print("didCompleteWithError ERROR", level: .full)
 148             delegate?.customHTTPProtocol(self, didFailWithError: error)
 149             client?.urlProtocol(self, didFailWithError: error)
 150             return
 151         }
 152         Debug.print("didCompleteWithError SUCCESS", level: .full)
 153         delegate?.customHTTPProtocolDidFinishLoading(self)
 154         client?.urlProtocolDidFinishLoading(self)
 155
 156         if cachePolicy == .allowed,
 157             let ext = task.originalRequest?.url?.pathExtension,
 158             CustomHTTPProtocol.cachedExtensions.contains(ext),
 159             let request = task.originalRequest,
 160             let response = task.response as? HTTPURLResponse,
 161             let expires = response.expires() {
 162             let cache = CachedURLResponse(response: response,
 163                                           data: data,
 164                                           userInfo: ["Expires": expires],
 165                                           storagePolicy: .allowed)
 166             CustomHTTPProtocol.kcdURLCache.storeCachedResponse(cache, for: request)
 167         }
 168     }
 169 }
 170
 171 extension HTTPURLResponse {
 172     private var httpDateFormatter: DateFormatter {
 173         let formatter = DateFormatter()
 174         formatter.dateFormat = "EEE',' dd' 'MMM' 'yyyy HH':'mm':'ss zzz"
 175         formatter.locale = Locale(identifier: "en_US")
 176         return formatter
 177     }
 178     func expires() -> Date? {
 179         if let cc = (allHeaderFields["Cache-Control"] as? String)?.lowercased(),
 180             let range = cc.range(of: "max-age="),
 181             let s = cc[range.upperBound..<cc.endIndex]
 182                 .components(separatedBy: ",")
 183                 .first,
 184             let age = TimeInterval(s) {
 185             return Date(timeIntervalSinceNow: age)
 186         }
 187         if let ex = (allHeaderFields["Expires"] as? String)?.lowercased(),
 188             let exp = httpDateFormatter.date(from: ex) {
 189             return exp
 190         }
 191         return nil
 192     }
 193 }