What's the best way to implement a Java-like ByteBuffer in Obj-C?

Question

I'm trying to build a application for the iPhone, although I am completely new to Obj-C. For one problem I'd use a ByteBuffer in Java, but I don't see any appropriate class in Apple's documentation. So I probably have to implement it on my own.

My question is, how to do it best:

• Is there a similar class in Obj-C? (That would be the best solution ;))
• Should I do it by using Obj-C classes like NSData?
• Or should I stay with plain C code?

Answer 1

You probably want NSMutableData.

Answer 2

My recollection of java.nio.ByteBuffer (from working with Java many moons ago) is that ByteBuffer implements sequential reads/writes to an array of bytes. This is analogous to an NSInputStream backed by an NSData (for input):

NSInputStream *inputStream = [NSInputStream inputStreamwithData:myData]; //assuming myData is NSData*

float myFloat;

if([inputStream hasBytesAvailable]) { // NO if you've already read to the end of myData
  NSInteger bytesRead = [inputStream read:&myFloat maxLength:sizeof(myFloat)];
  NSAssert(bytesRead == sizeof(myFloat);
}

You can do something similar with an NSOutputStream writing to an NSData.