how to read file with asyncSocket without knowing the file length? - ios

Question

I have a file server(base on java), it's very simple, when the client connect to it, it will automatically send a file to the client.
On the client side, it's also very simple, it just read from the socket until the read method return -1.
The implement code base on java looks like this:
InputStream is = socket.getInputStream();
byte[] buffer = new byte[1024];
int size = 0;
while((size = is.read(buffer)) != -1){
LogUtils.LOGD(TAG,"we have data in");
...
}
But now I want to implement the client on iOS device, and I deploy AsyncSocket ,
[sock connectToHost:hostname onPort:SYNC_DATABASE_PORT error:&err];
[sock readDataWithTimeout:3.0 tag:2];
and then, when the delegate callback:
-(void)socket:(GCDAsyncSocket *)sock didReadData:(NSData *)data withTag:(long)tag
{
NSLog(#"didReadData read data,len:%ld",(unsigned long)[data length]);
if (tag == 2) {
_totalReceivedLen += [data length];
[sock readDataWithTimeout:0.5 tag:2];
[self writeFile:data];
}
In this way, all data will be received, but I don't know how to determine wether the transmission have been completed?
I have tried another way like this:
[sock readDataToData:[[NSString stringWithFormat:#"%x",EOF] dataUsingEncoding:NSUTF8StringEncoding] withTimeout:-1 tag:2];
I supposed to end the reading when the data came to the -1 signal, but it actually doesn't work, the delegate was not called at all.
Thank you for you time, hope you can give me some advices.

Answer 1

jsut add “[sock readDataToData:[[NSString stringWithFormat:#"%x",EOF] dataUsingEncoding:NSUTF8StringEncoding] withTimeout:-1 tag:2];” in this funchtion:
func onSocket(sock: AsyncSocket!, didConnectToHost host: String!, port: UInt16) {
[sock readDataToData:[[NSString stringWithFormat:#"%x",EOF] dataUsingEncoding:NSUTF8StringEncoding] withTimeout:-1 tag:2]
}

Answer 2

I found a way to get around with it. When I look insight the asyncSocket source code, I found that When the server finished sending the file to client, it will automatically disconnect the client.So I do the ending file job at the socketDidDisconnect delegate like this:
-(void)socketDidDisconnect:(GCDAsyncSocket *)sock withError:(NSError *)err {
if (flag > 0) {
NSLog(#"done with sync database");
flag = 0;
...
}
}