Receiving broken/incomplete message using Sockets - iphone

Question

I'm new to socket programming, I did it by referring http://www.raywenderlich.com/3932/how-to-create-a-socket-based-iphone-app-and-server, I'm using php server, the problem I'm facing is, I'm able to send/receive messages using sockets, but my received messages are broken like My recieved msg should be "Hello abcd" but it gives me " " then after some time "llo" then after some time "abcd".
I'm using following code to receive messages:
- (void)stream:(NSStream *)theStream handleEvent:(NSStreamEvent)streamEvent {
switch (streamEvent) {
case NSStreamEventNone:
NSLog(#"Stream event none");
break;
case NSStreamEventOpenCompleted:
NSLog(#"Stream opened");
break;
case NSStreamEventHasBytesAvailable:
if (theStream == inputStream) {
int len=0;
uint8_t *buffer = (uint8_t *)calloc(1, (16*1024));
while ([inputStream hasBytesAvailable]) {
len = [inputStream read:buffer maxLength:sizeof(buffer)];
NSLog(#"byte available %d",len);
if (len > 0) {
NSMutableData* data=[[NSMutableData alloc] initWithLength:0];
//
[data appendBytes:(const void *)buffer length:len];
// NSString *s = [[NSString alloc] initWithData:data encoding:NSASCIIStringEncoding];
// NSLog(#"rs %#",s);
NSString *output = [[NSString alloc] initWithBytes:buffer length:len encoding:NSASCIIStringEncoding];
if (nil != output) {
NSLog(#"server said: %#", output);
[self messageReceived:output];
}
}
}
}
break;
case NSStreamEventHasSpaceAvailable:
NSLog(#"event space available");
break;
case NSStreamEventErrorOccurred:
NSLog(#"Can not connect to the host!");
break;
case NSStreamEventEndEncountered:
NSLog(#"end");
[theStream close];
[theStream removeFromRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
[theStream release];
theStream = nil;
break;
default:
NSLog(#"Unknown event");
}
}

Answer 1

I was facing same issue. What i did was instead of appending string in the delegate method i passed the string to another method, checked the inputstream for bytes and appended the string there. Here is the snippet from my app. Hope it helps.
- (void)stream:(NSStream *)theStream handleEvent:(NSStreamEvent)streamEvent {
switch (streamEvent) {
case NSStreamEventOpenCompleted:
NSLog(#"Stream opened");
break;
case NSStreamEventHasBytesAvailable:
if (theStream == inputStream) {
uint8_t buffer[1024];
NSInteger len = [inputStream read:buffer maxLength:sizeof(buffer)];
NSString *output;
if (len > 0) {
output = [[NSString alloc] initWithBytes:buffer length:len encoding:NSASCIIStringEncoding];
[self messageReceived:output];
}
}
break;
case NSStreamEventErrorOccurred:
{
NSLog(#"Can not connect to the host!");
[theStream close];
[theStream removeFromRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
UIAlertView *errorOccured = [[UIAlertView alloc] initWithTitle:#"Error" message:#"Some error occured." delegate:self cancelButtonTitle:#"Ok" otherButtonTitles:nil];
[errorOccured show];
}
break;
case NSStreamEventEndEncountered:
NSLog(#"Stream end occured");
break;
default:
NSLog(#"Unknown event");
}
}
- (void) messageReceived:(NSString *)message {
if (inputStream.hasBytesAvailable) {
[streamResponseStr appendString:message];
}else{
[streamResponseStr appendString:message];
[self parseServerResponse:streamResponseStr];
streamResponseStr = nil;
streamResponseStr = [[NSMutableString alloc] init];
}
}