[DIRMINA-829] AbstractIoBuffer.getSlice(int index, int length) has incorrect behavior

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.0.2
• Fix Version/s: 2.0.5
• Component/s: Core
• Assignee: Emmanuel Lécharny
• Reporter: Anton Sitnikov
• Created: 17/Apr/11 13:42
• Updated: 10/Jul/12 14:49
• Resolved: 10/Jul/12 14:49

Description

All indexed access function of IoBuffer (getXXX(int index, ...)) supposed to keep IoBuffer state intact. getSlice(int index, int length) method in AbstractIoBuffer class behave differenlty. After its execution buffer posistion is moved to value of index parameter:

    public final IoBuffer getSlice(int index, int length) {
        if (length < 0) {
            throw new IllegalArgumentException("length: " + length);
        }
        
        int limit = limit();
        
        if (index > limit) {
            throw new IllegalArgumentException("index: " + index);
        }
        
        int endIndex = index + length;

        if (capacity() < endIndex) {
            throw new IndexOutOfBoundsException("index + length (" + endIndex
                    + ") is greater " + "than capacity (" + capacity() + ").");
        }

        clear();
        position(index);
        limit(endIndex);

        IoBuffer slice = slice();
        position(index);
        limit(limit);
        return slice;
    }

As you can see, this method checks also resulting slice upper limit against original buffer capcity (not against limit), which I suppose is wrong too.

I think this method should be changed like this:

    public final IoBuffer getSlice(int index, int length) {
        if (length < 0) {
            throw new IllegalArgumentException("length: " + length);
        }
        
        int pos = position();
        int limit = limit();
        
        if (index > limit) {
            throw new IllegalArgumentException("index: " + index);
        }
        
        int endIndex = index + length;

        if (endIndex > limit) {
            throw new IndexOutOfBoundsException("index + length (" + endIndex
                    + ") is greater " + "than limit (" + limit + ").");
        }

        clear();
        position(index);
        limit(endIndex);

        IoBuffer slice = slice();
        position(pos);
        limit(limit);
        return slice;
    }