swift - iOS: Download .TXT file give strange result -

i'm trying download .txt file has 5mb size in 1 website

i tried download file directly , give correct size

i tried download via android downloadmanager.request , give correct size

except, in ios, while tried download via nsurlconnection, without 1 second, show successful download 5mb size however, when check in network receiving show used 25kb?

ps. if change download same domain .zip file, download properly

problem link: http://www.bluewindsolution.com/speed_test/downloads/download_file.txt

working link: http://www.bluewindsolution.com/speed_test/downloads/download_file.zip

here code

@ibaction func buttonclick(sender: anyobject) {     let timestamp = nsstring(format: "%.0f", nsdate().timeintervalsince1970)     let url:nsurl = nsurl(string: "http://www.bluewindsolution.com/speed_test/downloads/download_file.txt?time=\(timestamp)")!     var request:nsurlrequest = nsurlrequest(url: url, cachepolicy: nsurlrequestcachepolicy.reloadignoringlocalcachedata, timeoutinterval: 30.0)     startdate = nsdate()     nsurlconnection(request: request, delegate: self) }  func connectiondidfinishdownloading(connection: nsurlconnection, destinationurl: nsurl) {     println("finishdownload \(destinationurl)")      println("timetotal: \(timetotal)")     println("speed: \(speed) mbps")     println("filesize: \(filesize)") // it's show 5mb network receive 25kbps ?  it's not cache because it's happen @ first time also.      connection.cancel() }  func connection(connection: nsurlconnection, didwritedata byteswritten: int64, totalbyteswritten: int64, expectedtotalbytes: int64) {     let currentdate:nsdate = nsdate()      let tt = currentdate.timeintervalsincedate(startdate)     timetotal = tt // total time     speed = double(totalbyteswritten)/1024/1024*8/tt  // speed mbps     filesize = double(totalbyteswritten)/1024/1024  // mb      // use result real time     //println("timetotal: \(totaltime)")     //println("speed: \() mbps")     //println("filesize: \()") } 

output result

result of network receive in emulator

seems problem method connectiondidfinishdownloading. please use below delegate methods , it's working

  var mdata = nsmutabledata()   func connection(connection: nsurlconnection, didreceivedata data: nsdata) {     mdata.appenddata(data)     println("loading")   }    func connectiondidfinishloading(connection: nsurlconnection) {     let documentspath = nssearchpathfordirectoriesindomains(.documentdirectory, .userdomainmask, true)[0] as! nsstring     let filepath = documentspath.stringbyappendingpathcomponent("text.txt")     mdata.writetofile(filepath, atomically: true)     println("\(filepath)")   }    func connection(connection: nsurlconnection, didfailwitherror error: nserror) {     println("\(error)")   }