GCDAsyncSocket - Read stream never completes - iphone

Question

I am playing with GCDAsyncSocket (MRC / iOS5.1) for a while, especially with "large" files (5 - 10 mb). Unfortunately sometimes the read stream is never completed (e.g. it gets stuck) just a few bytes at the end of the stream; the didReadPartialDataOfLength: stops giving me information and the didReadData is not fired at all.
Here's some of my code (for both writing / reading examples the connection between the host and client have been established)
WRITING
#define kHeadTag 0
#define kDataTag 1
typedef struct {
NSUInteger size;
} head_t;
-(void)sendData:(NSData *)__data {
_sendData = [__data retain];
head_t header;
header.size = __data.length;
[_socket writeData:[NSData dataWithBytes:&header
length:sizeof(header)]
withTimeout:-1
tag:kHeadTag];
}
-(void)socket:(GCDAsyncSocket *)sock
didWriteDataWithTag:(long)tag {
if (tag == kHeadTag) {
[sock writeData:_sendData withTimeout:-1 tag:kDataTag];
[_sendData release];
_sendData = nil;
}
}
READING
-(void)socket:(GCDAsyncSocket *)sock
didReadData:(NSData *)data
withTag:(long)tag {
switch (tag) {
// ------------------------------------- HEAD
case kHeadTag:{
head_t head;
[data getBytes:&head length:sizeof(head)];
_readHead = head;
NSLog(#"Received header (total size = %i bytes)", head.size);
[sock readDataToLength:head.size
withTimeout:-1
tag:kDataTag];
}
break;
// ------------------------------------- BODY
case kDataTag: {
NSLog(#"Data received with %i bytes", data.length);
[sock readDataToLength:sizeof(head_t) withTimeout:-1 tag:kHeadTag];
}
break;
}
};
-(void)socket:(GCDAsyncSocket *)sock
didReadPartialDataOfLength:(NSUInteger)partialLength
tag:(long)tag {
if (tag == kDataTag) {
NSLog(#"Data read with %i bytes", partialLength);
}
};
I hope this is enough code to see what I'm doing wrong or maybe this is a bad practice for writing/reading large chunks of data.

Answer 1

I added
[self.partnerSocket writeData:[GCDAsyncSocket CRLFData] withTimeout:-1 tag:0];
at the end of sendData: method, and it works fine for me. You just have to append separator chars at the end of the data.
I can transfer around 48MB of file from one iDevice to other iDevice