Is this usage of NSMutableString a memory leak?

Question

I'm currently using an instance variable that's an NSMutableString in a class which is a delegate for NSURLConnection. The variable is responsible for building a string of data that's returned from the delegate method:

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data 

The string, 'foo', has a property set with retain on it. It is alloc'd in my classes init method very straight forward in this fashion:

dataString = [[NSMutableString alloc] init];

It is released in the classes dealloc method.

In connection:didReceiveData:, I use the var like this:

    NSString *tmpString = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
    [dataString appendString:tmpString];
    [tmpString release];

Now this is where things get tricky. Since the class where I set the NSURLConnection delegate is a singleton (it mainly handles NSURL* type calls), I need to becareful with how I re-use my objects. Therefor, in my connectionDidFinishLoading: class I have the following:

   // cache away data currently in dataString.
[dataString release];
dataString = [[NSMutableString alloc] init];

Does that strategy of handling my dataString make your eyes bleed? Am I leaking memory? What can I do that's smarter?

Answer 1

Are you going to ask us whether every use of an object in your application is a memory leak?

Read the documentation. Learn the rules of object ownership and you will have your answer already, every time.

And if you suspect a leak, run Instruments' ObjectAlloc probe. You've done this once already , so clearly you know how. There's also the leaks command .