How to read data from NSInputStream explicitly in swift? - sockets

Question

I am using a socket connect in my application.
Here's my SocketConnection.swift
init(host: String, port:UInt32){
self.host = host
self.port = port
self.status = false
output = ""
super.init()
}
func stream(aStream: NSStream, handleEvent aStreamEvent: NSStreamEvent) {
switch aStreamEvent {
case NSStreamEvent.OpenCompleted:
break
case NSStreamEvent.HasBytesAvailable:
break
case NSStreamEvent.HasSpaceAvailable:
break
case NSStreamEvent.EndEncountered:
// aStream.close()
aStream.removeFromRunLoop(NSRunLoop.currentRunLoop(), forMode: NSDefaultRunLoopMode)
break
case NSStreamEvent.None:
break
case NSStreamEvent.ErrorOccurred:
break
default:
println("# something weird happend")
break
}
}
func connect() {
println("# connecting to \(host):\(port)")
var cfReadStream : Unmanaged<CFReadStream>?
var cfWriteStream : Unmanaged<CFWriteStream>?
CFStreamCreatePairWithSocketToHost(kCFAllocatorDefault, host, port, &cfReadStream, &cfWriteStream)
inputStream = cfReadStream!.takeRetainedValue()
outputStream = cfWriteStream!.takeRetainedValue()
inputStream!.delegate = self
outputStream!.delegate = self
inputStream!.scheduleInRunLoop(NSRunLoop.currentRunLoop(), forMode: NSDefaultRunLoopMode)
outputStream!.scheduleInRunLoop(NSRunLoop.currentRunLoop(), forMode: NSDefaultRunLoopMode)
inputStream!.open()
outputStream!.open()
}
func read(){
var buffer = [UInt8](count: bufferSize, repeatedValue: 0)
output = ""
while (self.inputStream!.hasBytesAvailable){
var bytesRead: Int = inputStream!.read(&buffer, maxLength: buffer.count)
if bytesRead >= 0 {
output += NSString(bytes: UnsafePointer(buffer), length: bytesRead, encoding: encoding)! as String
} else {
println("# error")
}
println("> \(output)")
}
}
func send(message:String){
let data:NSData = message.dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: false)!
let bytesWritten = self.outputStream!.write(UnsafePointer(data.bytes), maxLength: data.length)
println("< send to \(host)")
}
In my ViewController.swift,
I am connecting to the server like this
var socketConnection = SocketConnection(host: _ip, port: _port)
socketConnection.connect()
socketConnection.send(urlString)
socketConnection.read()
Now I can send my url string via socket but when I am reading explicitly I am not getting the data from the server if I call the same read function from the NSStreamEvent.HasBytesAvailable case it printing the server response.. but how can I trigger the event queue?
I want to call this socketConnection.read() explicitly.. How can I do that?
After 2 sec of connection, its closes the connection channel, I want to keep alive my connection until I close.
Help me out from this problem.
Thanks

Answer 1

Change your read() as below and then call read() func in case NSStreamEvent.HasBytesAvailable:
private func read(stream: InputStream) {
let maxReadLength = 1024
let buffer = UnsafeMutablePointer<UInt8>.allocate(capacity: maxReadLength)
while stream.hasBytesAvailable {
let numberOfBytesRead = inputStream?.read(buffer, maxLength: maxReadLength)
if numberOfBytesRead! < 0 {
if let _ = inputStream?.streamError {
break
}
}
if let message = processedMessageString(buffer: buffer, length: numberOfBytesRead!) {
delegate?.receivedMessage(message: message)
}
}
}

Answer 2

You do not need to call read functionality explicitly. Change your read func as below and call in case case Stream.Event.hasBytesAvailable:.
func read(stream: InputStream) {
let maxReadLength = 1024
var buffer = [uint8](repeating: 0, count: maxReadLength)
while stream.hasBytesAvailable {
let numberOfBytesRead : Int = stream.read(&buffer, maxLength: maxReadLength)
if numberOfBytesRead < 0 {
if let _ = stream.streamError {
break
}
}
if let message = processedMessageString(buffer: buffer, length: numberOfBytesRead) {
delegate?.receivedMessage(message: message)
}
}}
If you want to call read() explicitly then you need to pass the stream as parameters and call the read function in ViewController class—
socketConnection.read(stream)