NSInputStream无法读取数据

Question

我在处理流事件的时候遇到了点问题。我有一个通过TCP连接到服务器客户端app，客户端需要持续接收服务端发来的json数据。

到目前为止，我完成了以下事情：

建立连接：

// Create Stream

var readStream : Unmanaged<CFReadStream>?
var writeStream : Unmanaged<CFWriteStream>?

let host : CFString = NSString(string: serverUrl!)
let port : UInt32 = UInt32(serverPort)

CFStreamCreatePairWithSocketToHost(kCFAllocatorDefault, host, port, &readStream, &writeStream)

inputStream = readStream!.takeUnretainedValue()
outputStream = writeStream!.takeRetainedValue()

inputStream!.delegate = self
outputStream!.delegate = self

inputStream!.scheduleInRunLoop(NSRunLoop.currentRunLoop(), forMode: NSDefaultRunLoopMode)
outputStream!.scheduleInRunLoop(NSRunLoop.currentRunLoop(), forMode: NSDefaultRunLoopMode)

inputStream!.open()
outputStream!.open()

// Send Authentication Data

let uid = 1000000000 + arc4random() % 2000000000
let joinRoomMsg : NSData = "{\"roomid\": \(realRoomID!), \"uid\": \(uid)}".dataUsingEncoding(NSUTF8StringEncoding)!

sendSocketData(outputStream!, totalLength: joinRoomMsg.length + 16, headerLength: 16, protocolVersion: 1, action: 7, param5: 1, data: joinRoomMsg)

这是sendSocketData 函数:

func sendSocketData(outputStream: NSOutputStream, totalLength: Int32, headerLength: CShort, protocolVersion: CShort, action: Int32, param5: Int32, data: NSData?) {

    var totalLengthBE = totalLength.bigEndian
    var headerLengthBE = headerLength.bigEndian
    var protocolVersionBE = protocolVersion.bigEndian
    var actionBE = action.bigEndian
    var param5BE = param5.bigEndian

    withUnsafePointers(&totalLengthBE, &headerLengthBE, &protocolVersionBE) {
        outputStream.write(UnsafePointer($0), maxLength: sizeofValue(totalLengthBE))
        outputStream.write(UnsafePointer($1), maxLength: sizeofValue(headerLengthBE))
        outputStream.write(UnsafePointer($2), maxLength: sizeofValue(protocolVersionBE))
    }

    withUnsafePointers(&actionBE, &param5BE) {
        outputStream.write(UnsafePointer($0), maxLength: sizeofValue(actionBE))
        outputStream.write(UnsafePointer($1), maxLength: sizeofValue(param5BE))
    }

    if data != nil {
        outputStream.write(UnsafePointer(data!.bytes), maxLength: data!.length)
    }
}

流处理:

func stream(aStream: NSStream, handleEvent eventCode: NSStreamEvent) {
    if aStream === inputStream {
        switch eventCode {
        case NSStreamEvent.ErrorOccurred:
            print("iStream ErrorOccurred")
        case NSStreamEvent.EndEncountered:
            print("iStream EndEncountered")
        case NSStreamEvent.OpenCompleted:
            print("iStream Opened")
        case NSStreamEvent.HasBytesAvailable:
            print("Stream HasBytesAvailable")
            // 读取数据...
        default:
            print("iStream Unknow")
        }
    } else if aStream === outputStream {
        switch eventCode {
        case NSStreamEvent.OpenCompleted:
            print("oStream Opened")
        case NSStreamEvent.ErrorOccurred:
            print("oStream ErrorOccurred")
        case NSStreamEvent.HasSpaceAvailable:
            print("oStream HasSpaceAvailable")
        default:
            print("oStream Unknow")
        }
    }
}

Wireshark抓包表明服务器的确发送了json数据给我.

按理说我现在应该能从 inputStream里通过NSStreamEvent.HasBytesAvailable读数据。

我的问题就是: 流事件处理给了我一个NSStreamEvent.HsaSpaceAvailable以后就不动了。nputStream.hasBytesAvailable返回false，我什么也读不了。

根据 Stream Programing Guide:

If the delegate receives an NSStreamEvent.HasSpaceAvailable event and does not write anything to the stream, it does not receive further space-available events from the run loop until the NSOutputStream object receives more bytes. When this happens, the run loop is restarted for space-available events.

但我已经 没有 任何需要写入流的数据了。

我试着随便写入一些数据到流里去，但是不管用。
我也试过等outputStream.hasSpaceAvailable返回true以后再发送验证信息，但这样服务器就不发json数据给我了。

是我的代码出了什么问题吗?或是说我不应该这么用？

Answer 1

http://bbs.csdn.net/topics/390998749