Receiving broken/incomplete message using Sockets

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");
    }

}

I might be wrong, but shouldn't sizeof(buffer) return the size of the pointer and not of the buffer? I mean, the allocation being dynamic... another point, when you allocate your NSMutableData, why doing it with length 0 when you know the final length (len)? — Jerome Diaz, Apr 22 '13 at 07:02
plz check this one http://stackoverflow.com/questions/15583366/tcp-socket-programming-in-ios-server-client-response — Nitesh Meshram, Apr 22 '13 at 07:14
@NiteshMeshram thnx but I already checked it, din't help me. — Eager Beaver, Apr 22 '13 at 07:15
@eager-beaver what I was going to suggest you is already in the answer from Deepesh you might want to also check the php side of the issue — Jerome Diaz, Apr 22 '13 at 11:26

score 0 · Answer 1 · answered Apr 22 '13 at 08:52

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];
    }
}

Thnx but It gives same result to me. :( – Eager Beaver Apr 22 '13 at 09:24 — Eager Beaver, Apr 22 '13 at 09:24

Receiving broken/incomplete message using Sockets

1 Answers1