AS3 Socket ProcessEvent.SOCKET_DATA seems not triggered - actionscript-3

Question

We use AS3 Event:ProcessEvent.SOCKET_DATA to listen for socket data.
So this is my AS3 code for socket data handle.
private function packetHandler( e:ProgressEvent ):void
{
while( m_socket.bytesAvailable && m_socket.bytesAvailable >= pLen )
{
//pLen means the packet length
//pLen init is zero
if( pLen == 0 )
{
//PACKET_LEN stands for the solid length of one packet
//PACKET_LEN = HEAD_LEN + 4
//the 4 means an unsigned int which means the packet content length
if( m_socket.bytesAvailable > PACKET_LEN )
{
m_socket.readBytes( headByteBuffer, 0, HEAD_LEN );
headByteBuffer.clear();
pLen = m_socket.readUnsignedInt() + 4;
}
else
{
break;
}
}
//recieved a whole packet now handle it
else
{
var newPacket:ByteArray = new ByteArray();
newPacket.endian = Endian.LITTLE_ENDIAN;
m_socket.readBytes( newPacket, 0, pLen );
parasMsg( newPacket, pLen-4 );
pLen = 0;
}
}
}
A whole packet can be described in this picture:
My Problem is: When there has one incomplete packet received in Flash and triggered the handle.
But the left part of the packet will never trigger the handle and it seems like that the left part of the packet has lost!!!
I used a capture tool, find that the tcp packet is ok, but why the left part doesn't trigger the event again?
You can get more debug information below. Thank you!
This is my log:
byteava means bytesAvailable of m_socket
==>sendPacket: {"rangeID":"1","uid":"145962","serviceType":"copyscene","cmd":"CopySceneMoveAsk","pathPoint":[{"col":7,"row":6},{"col":7,"row":5},{"col":7,"row":4},{"col":7,"row":3},{"col":6,"row":3}],"sn":"79","smallPathPoint":[[22,19],[22,18],[22,17],[22,16],[22,15],[22,14],[22,13],[21,13],[21,12],[21,11],[20,11],[20,10]]}, bytesLoaded = 463
ProgressEvent Triggered!0 socket byteava = 373 evt loaded:373 evt total:0 evt:[ProgressEvent type="socketData" bubbles=false cancelable=false eventPhase=2 bytesLoaded=373 bytesTotal=0]
Find a packet from socket, pLen=288 socket byteava = 276
ProgressEvent Triggered!288 socket byteava = 441 evt loaded:165 evt total:0 evt:[ProgressEvent type="socketData" bubbles=false cancelable=false eventPhase=2 bytesLoaded=165 bytesTotal=0]
Start to Read a packet to buffer, pLen=288 socket byteava = 441
whole packet content: Readed a packet to buffer, pLen=288 socket byteava = 153
Server packet content byte buffer ava:288 len：288 pos: 0
Server Paras Data : data len: 284 data content: {"cmd":"CopySceneMoveNotify","gtcmd":"108","layer":"1","pathPoint":[{"col":7,"row":6},{"col":7,"row":5},{"col":7,"row":4},{"col":7,"row":3},{"col":6,"row":3}],"smallPathPoint":[[22,19],[22,18],[22,17],[22,16],[22,15],[22,14],[22,13],[21,13],[21,12],[21,11],[20,11],[20,10]HTTP/1.1 200
_[20,10]HTTP/1.1 200_ This is what went wrong!! The incomplete packet cat with another packet's header.
Here is the capture of the TCP connections:
Hope you can vote it up so that I can put my pictures of this question on!
My English is not very good, hope you can understand what I mean.
Thank you!

Answer 1

The Socket's event flash.events.ProgressEvent.SOCKET_DATA will fire when you receive the data at this point you can get the received bytes ( check .bytesAvailable ). When the msg is split into multiple packages you will receive event for each packet.
In your case maybe the pLen have wrong value when check m_socket.bytesAvailable >= pLen.
I assume you send the msg size in the begging of the message ( in this case you can check if the whole msg is received ). In this case you must have a class member (ByteArray ) as buffer that holds a received bytes. When new data come you must copy the new bytes to this member and than check if you receive whole msg. If buffer contains whole msg than remove the msg from it.
In general your event handler must looks like this:
protected function onSocketData( pEvt: Event ): void
{
try
{
if ( 0 < pEvt.target.bytesAvailable )
{
var byteStream: ByteArray = new ByteArray();
pEvt.target.readBytes( byteStream, 0, Socket( pEvt.target ).bytesAvailable );
// Append readed data to your buffer
do
{
//Check if you have enough bytes to read whole msg and execute it
//do..while because maybe it can be more than one msg in buffer
}
while ( null != msgContent );
}
}
catch ( exc )
{
}
}

Answer 2

Problem should caused by the packet's solid header.
Below is the 93 bytes solid header of a packet.
private static const HTTP_RESPONSE_CONTENT : String = "HTTP/1.1 200 OK \r\n"
+ "Connection: keep-alive \r\n"
+ "Content-Length: 280 \r\n"
+ "Content-Type: text/html \r\n\r\n";
This header will be in every packet's header, which AS3 could treat it to a http and might cut the flow with Content-Length: 280. So the left part of the 280 bytes will never trigger the SOCKET_DATA event.
When I remove this header, it's ok now.