src/main/java/com/it_jaros/jscanner/PortRangeIterator.java


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package com.it_jaros.jscanner;

import java.util.BitSet;
import java.util.Iterator;
import java.util.NoSuchElementException;

import static com.it_jaros.jscanner.PortRange.MAX_PORT;
import static com.it_jaros.jscanner.PortRange.MIN_PORT;

public class PortRangeIterator implements Iterator<Integer> {

    private int currentPortCursor;
    private int done = 0;
    private final BitSet availablePorts = new BitSet(MAX_PORT);

    PortRangeIterator(BitSet specifiedPorts) {
        availablePorts.or(specifiedPorts);
        currentPortCursor = availablePorts.nextSetBit(MIN_PORT);
    }

    @Override
    public Integer next() {
        int p = availablePorts.nextSetBit(currentPortCursor);
        if (p > 0) {
            availablePorts.clear(p);
            currentPortCursor = p + 1;
            done++;
            return p;
        }

        throw new NoSuchElementException("Reached end of port range");
    }

    @Override
    public boolean hasNext() {
        return availablePorts.nextSetBit(currentPortCursor) > 0;
    }
}