public NormalizedRanges subtract()

in src/java/org/apache/cassandra/dht/NormalizedRanges.java [137:202]
56 lines of code
27 McCabe index (conditional complexity)

    public NormalizedRanges<T> subtract(NormalizedRanges<T> b)
    {
        if (b.isEmpty())
            return this;

        if (b.size() == 1 && b.get(0).isFull())
            return NormalizedRanges.empty();

        if (this.size() == 1 && this.get(0).isFull())
            return b.invert();

        List<Range<T>> remaining = new ArrayList<>();
        Iterator<Range<T>> aIter = this.iterator();
        Iterator<Range<T>> bIter = b.iterator();
        Range<T> aRange = aIter.hasNext() ? aIter.next() : null;
        Range<T> bRange = bIter.hasNext() ? bIter.next() : null;
        while (aRange != null && bRange != null)
        {
            boolean aRMin = aRange.right.isMinimum();
            boolean bRMin = bRange.right.isMinimum();

            if (aRMin && bRMin)
            {
                if (aRange.left.compareTo(bRange.left) < 0)
                    remaining.add(new Range<>(aRange.left, bRange.left));
                checkState(!aIter.hasNext() && !bIter.hasNext());
                aRange = null;
                break;
            }

            if (!aRMin && aRange.right.compareTo(bRange.left) <= 0)
            {
                remaining.add(aRange);
                aRange = aIter.hasNext() ? aIter.next() : null;
            }
            else if (!bRMin && aRange.left.compareTo(bRange.right) >= 0)
            {
                bRange = bIter.hasNext() ? bIter.next() : null;
            }
            else
            {
                // Handle what remains to the left of the intersection
                if (aRange.left.compareTo(bRange.left) < 0)
                {
                    remaining.add(new Range(aRange.left, bRange.left));
                }

                // Handle what remains to the right of the intersection
                if (!aRMin && (aRange.right.compareTo(bRange.right) <= 0 | bRMin))
                    aRange = aIter.hasNext() ? aIter.next() : null;
                else
                    aRange = new Range(bRange.right, aRange.right);
            }
        }

        while (aRange != null)
        {
            remaining.add(aRange);
            aRange = aIter.hasNext() ? aIter.next() : null;
        }

        NormalizedRanges<T> result = normalizedRanges(remaining);
        if (Range.EXPENSIVE_CHECKS)
            checkState(result.equals(Range.normalize(Range.subtract(this, b))));
        return result;
    }