How to convert UnsafeMutablePointer<UInt8> to UIImage in Swift - ios

Question

I have been trying to send image data from android and receive at iOS using Socket,But the problem is that I am not able to show Image from data which is received from stream.
Here is the complete code:-
Setting Up the network communication
var readStream: Unmanaged<CFReadStream>?
var writeStream: Unmanaged<CFWriteStream>?
CFStreamCreatePairWithSocketToHost(kCFAllocatorDefault,
ip as CFString,
3003,
&readStream,
&writeStream)
inputStream = readStream!.takeRetainedValue()
outputStream = writeStream!.takeRetainedValue()
inputStream.delegate = self
// outputStream.delegate = self
inputStream.schedule(in: .current, forMode: RunLoop.Mode.common)
outputStream.schedule(in: .current, forMode: RunLoop.Mode.common)
inputStream.open()
outputStream.open()
Receive data through the delegates as shown below:-
extension ChatRoom: StreamDelegate {
func stream(_ aStream: Stream, handle eventCode: Stream.Event) {
switch eventCode {
case Stream.Event.hasBytesAvailable:
print("new message received")
readAvailableBytes(stream: aStream as! InputStream)
case Stream.Event.endEncountered:
print("end received")
stopStreamSession()
case Stream.Event.errorOccurred:
print("error occurred")
case Stream.Event.hasSpaceAvailable:
print("has space available")
case Stream.Event.openCompleted:
print("Stream opened")
default:
print("some other event...")
break
}
}
private func readAvailableBytes(stream: InputStream) {
let buffer = UnsafeMutablePointer<UInt8>.allocate(capacity: maxReadLength)
while stream.hasBytesAvailable {
let numberOfBytesRead = inputStream.read(buffer, maxLength: maxReadLength)
if numberOfBytesRead < 0 {
if let _ = stream.streamError {
break
}
}
NSLog("number of bytes read = %i", numberOfBytesRead)
if numberOfBytesRead > 0 {
dataOfImage.append(buffer, count: numberOfBytesRead)
}
}
}
}
I have been trying to show image from data received using UIImage(data:dataOfImage), But it is showing nil , when I inspect the dataOfImage it consists of all the data received from stream.
Can anyone suggest a way to get the image out of UnsafeMutablePointer<UInt8> Data.
Also if there is any better approach for data transfer through sockets, Please do Suggest..

Answer 1

Rather than allocate memory declare a buffer variable with the capacity of maxReadLength.
And stream(_:handle:) is called multiple times. You have to check the result of the read function
private var dataOfImage = Data()
private func readAvailableBytes(stream: InputStream) {
var buffer = [UInt8](repeating: 0, count: maxReadLength)
let bytesRead = inputStream.read(&buffer, maxLength: maxReadLength)
switch bytesRead {
case 0: // success, end of file
case -1: // error
default: // append data
dataOfImage.append(contentsOf: buffer)
}
NSLog("number of bytes read = %i", bytesRead)
}