/**

  * Back 2 Browser Bytecode Translator

  * Copyright (C) 2012 Jaroslav Tulach <jaroslav.tulach@apidesign.org>

  *

  * This program is free software: you can redistribute it and/or modify

  * it under the terms of the GNU General Public License as published by

  * the Free Software Foundation, version 2 of the License.

  *

  * This program is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

  * GNU General Public License for more details.

  *

  * You should have received a copy of the GNU General Public License

  * along with this program. Look for COPYING file in the top folder.

  * If not, see http://opensource.org/licenses/GPL-2.0.

  */

 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);

             put(exStart, td.start_pc, td);

             put(exStop, td.end_pc, td);

         }

     }

     private static void put(Hashtable h, short key, TrapData td) {

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

         Vector v = (Vector) h.get(s);

         if (v == null) {

             v = new Vector(1);

             h.put(s, v);

         }

         v.add(td);

     }

     private boolean processAll(Hashtable h, Short key, boolean add) {

         boolean change = false;

         Vector v = (Vector)h.get(key);

         if (v != null) {

             int s = v.size();

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

                 TrapData td = (TrapData)v.elementAt(i);

                 if (add) {

                     add(td);

                     change = true;

                 } else {

                     remove(td);

                     change = true;

                 }

             }

         }

         return change;

     }

     public boolean advanceTo(int i) {

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

         boolean ch1 = processAll(exStart, s, true);

         boolean ch2 = processAll(exStop, s, false);

         return ch1 || ch2;

     }

     public boolean useTry() {

         return currentCount > 0;

     }

     public TrapData[] current() {

         TrapData[] copy = new TrapData[currentCount];

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

             copy[i] = current[i];

         }

         return copy;

     }

     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) {

         if (currentCount == 0) {

             return;

         }

         int from = 0;

         while (from < currentCount) {

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

                 break;

             }

         }

         while (from < currentCount) {

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

             current[from] = null;

             from++;

         }

         currentCount--;

     }

 }