Re: Having a weird error with NSStreams
Re: Having a weird error with NSStreams
- Subject: Re: Having a weird error with NSStreams
- From: Jens Alfke <email@hidden>
- Date: Tue, 15 Sep 2009 15:52:44 -0700
On Sep 15, 2009, at 2:36 PM, Development wrote:
while (0 < remainingToWrite) {
int actuallyWritten = 0;
actuallyWritten = [_outStream write:marker
maxLength:remainingToWrite];
remainingToWrite -= actuallyWritten;
marker += actuallyWritten;
}
I assume _outStream is in blocking mode (you haven't hooked it up to a
runloop), right? Otherwise this is going to spin like crazy.
while ((NSInputStream*)[stream hasBytesAvailable])
{
NSLog(@"In comming");
if (![(NSInputStream*)stream getBuffer:&buffer length:&len]) {
int amount = [(NSInputStream*)stream read:buf
maxLength:sizeof(buf)];
buffer = buf;
len = amount;
}
if (0 < len) {
if (!dataBuffer) {
dataBuffer = [[NSMutableData alloc] init];
}
[dataBuffer appendBytes:buffer length:len];
[cardData appendData:dataBuffer];
}
}
This stuff with dataBuffer doesn't make sense to me. Every time around
the loop you append the incoming bytes to dataBuffer, but then you
append all of dataBuffer to cardData -- so cardData will contain
multiple copies of the incoming bytes. So if it reads "111", then
"222", then "333", cardData will end up with "111111222111222333".
NSString * string = [[NSString alloc]initWithCString:
[dataBuffer bytes]];
Yikes! This has a couple of major problems.
* It assumes that dataBuffer is null-terminated. There's nothing in
your code that guarantees this. If for some reason dataBuffer's data
doesn't end with a null bytes, your app could crash.
* Never use -initWithCString:. It's deprecated, for good reason. The
encoding is unspecified, so it ends up using whatever your "default
encoding" is, and that varies depending on the user's preferred
language. The end result is that the contents of the string are quite
unpredictable if the data contains any non-ascii characters. Instead
you should use +initWithCString:encoding:.
In this case the method you want is probably -[initWithData:encoding:].
<plug href="http://bitbucket.org/snej/mynetwork/wiki/Home";>
Have you looked at my MYNetwork library? It does all the socket gunk
for you, plus Bonjour, and it has a very powerful high-level protocol
called BLIP for sending messages and replies over a socket.
</plug>
—Jens_______________________________________________
Cocoa-dev mailing list (email@hidden)
Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden