iOS Swift 下载许多小文件的最快方式

Question

我正在编写一个 iPad 应用程序，需要从服务器下载许多但相当小的 .json 和 .jpg 文件。

所以我是这样做的:

    ///Function to allow for recursive calls to syncronize inspections sequentially.
    func getInspection(ip: String, view: sensorSyncronizationDelegate, idarr:[IdData], appDelegate: AppDelegate){
    let inspectionID = idarr[0]
    var newArr = idarr
    //A task is created for each inspection that needs to be downloaded, and the json is parsed and added to the database.
    if self.session != nil {
        let inspectionURL = NSURL(string: "http://\(ip)/inspections/\(inspectionID.id!).json")
        let inspectionTask = self.session!.dataTaskWithURL(inspectionURL!) { (data, response, error) in
            //If data is nil, end the task.
            if data == nil {
                view.setInspectionSyncCompleted()
                view.completion("Error: Timeout please ensure Instrument is on, and attempt syncronization again")
                print(error)
                return
            }

            //if newArr is NOT empty make a recursiv call to getInspection()
            newArr.removeAtIndex(0)
            if !newArr.isEmpty{
                self.getInspection(ip, view: view, idarr: newArr, appDelegate: appDelegate)
            }else{
                self.syncMisc(ip, view: view)
            }

(我一直在使用 dataTaskWithURL)

session 是这样设置的:

var session : NSURLSession?

///Function to set up various http configurations, and call the various syncronization functions.
func syncWithSensor(view: sensorSyncronizationDelegate, ip: String!){

        //Session Configuration
        let config = NSURLSessionConfiguration.defaultSessionConfiguration()
        config.allowsCellularAccess = true
        config.timeoutIntervalForRequest = 30
        config.timeoutIntervalForResource = 60

        config.URLCache = nil

        //Authentication config
        let userpasswordString = "MAMA:PassWord"
        let userpasswordData = userpasswordString.dataUsingEncoding(NSUTF8StringEncoding)
        let base64encodedCreds = userpasswordData!.base64EncodedStringWithOptions([])
        let authString = "Basic \(base64encodedCreds)"
        config.HTTPAdditionalHeaders = ["Authorization" : authString, "Connection" : "Upgrade"]

        session = NSURLSession(configuration: config)

    //Check if for some reason ip is invalid
    if ip == nil{
        view.setSeriesSyncCompleted()
        view.setTemplateSyncCompleted()
        view.setInspectionSyncCompleted()
        view.completion("Error: Failed to connect to ***, please reset connection")
    }

    //Call the inspection sync function.
    syncInspections(ip, view: view)
}

//Function to respond to authentication challenges.
func URLSession(session: NSURLSession, task: NSURLSessionTask,  didReceiveChallenge challenge: NSURLAuthenticationChallenge, completionHandler: (NSURLSessionAuthChallengeDisposition, NSURLCredential!) -> Void) {
    let credential = NSURLCredential(user: "MAMA", password: "PassWord", persistence: .ForSession)
    completionHandler(NSURLSessionAuthChallengeDisposition.UseCredential, credential)
}

是的，它工作得很好。我可以在 22 秒内下载 280 多个文件(.json 和 .jpg)，这很不错，但对于用户来说，查看下载计数器的时间很长。

而且计划是，拥有更多......所以我真的需要一种方法来更快地做到这一点。

如果需要，我可以提供更多我正在使用的代码。

提前致谢:)

Answer 1

尝试使用 json 和图像批处理进行优化(服务器端优化)。在一段时间内下载一个大文件总比下载很多小文件好。如果您始终需要所有这些，这对电池生命周期来说是一个巨大的胜利，正如 documentation 中所指出的那样。 .