Java Buffer which can tell if it's dirty

Question

Due to the existing structure of code, which looks like this:

// Read buffer (using ByteBuffer)
// Pass buffer to a remote method, which MIGHT write to it
// Write buffer back if dirty

I want that my buffer should be able to identify if it is written to (if it's dirty). I didn't find any buffer implementation in java with a dirty flag.

In all these cases my code is already passing around ByteBuffers, in order to add this dirty flag should I:

simply wrap the ByteBuffer implementation with dirty flag
Write a class with underlying byte array, add dirty big and other operations (get/put int or long) and re-create the ByteBuffer by wrapping around the byte array
Extend the ByteBuffer class? (I'd be happy to implement the get/put but there are WAY TOO many methods to be implemented)

Also, what are the overheads of wrapping the ByteBuffer implementation?

Why do you need to know if it is dirty. Perhaps there is another way such as using memory mapped files. — Peter Lawrey, Sep 07 '13 at 17:46

score 1 · Accepted Answer · answered Sep 07 '13 at 15:24

This is a problem where the decorator pattern applies. You are strictly adding simple functionality to an existing class that's already in use. In this case, extending the class by inheritance is a natural and low threat implementation.

The overhead in Java of using the extended class vs. the base class is essentially zero. I am not counting as "overhead" the space for the dirty flag and the few instructions needed to implement it. But these costs are very low as well.

I was just going to write the exact same thing you did, so +1 for beating me to it :) — Ibrahim Najjar, Sep 07 '13 at 15:26

Java Buffer which can tell if it's dirty

1 Answers1