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package org.apidesign.javap;

/**

 *

 * @author Jaroslav Tulach <jtulach@netbeans.org>

 */

public final class TrapDataIterator {

    private final Hashtable exStart = new Hashtable();

    private final Hashtable exStop = new Hashtable();

    private TrapData[] current = new TrapData[10];

    private int currentCount;

    TrapDataIterator(Vector exceptionTable) {

        for (int i=0 ; i < exceptionTable.size(); i++) {

            final TrapData td = (TrapData)exceptionTable.elementAt(i);

            exStart.put(td.start_pc, td);

            exStop.put(td.end_pc, td);

        }

    }

    public void advanceTo(int i) {

        Short s = Short.valueOf((short)i);

        TrapData e = (TrapData) exStart.get(s);

        if (e != null) {

            add(e);

        }

        e = (TrapData) exStop.get(s);

        if (e != null) {

            remove(e);

        }

    }

    public boolean useTry() {

        return currentCount > 0;

    }

    public TrapData[] current() {

        return current;

    }

    private void add(TrapData e) {

        if (currentCount == current.length) {

            TrapData[] data = new TrapData[currentCount * 2];

            for (int i = 0; i < currentCount; i++) {

                data[i] = current[i];

            }

            current = data;

        }

        current[currentCount++] = e;

    }

    private void remove(TrapData e) {

        int from = 0;

        while (from < currentCount) {

            if (e == current[from++]) {

                break;

            }

        }

        while (from < currentCount) {

            current[from - 1] = current[from];

            current[from] = null;

            from++;

        }

        currentCount--;

    }

}