/**

  * Back 2 Browser Bytecode Translator

  * Copyright (C) 2012-2015 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.vm4brwsr;

 import java.io.IOException;

 import java.io.InputStream;

 import java.net.URL;

 import java.util.Enumeration;

 /**

  *

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

  */

 public final class BytesLoader {

     private static final StringArray requested = new StringArray();

     public byte[] get(String name) throws IOException {

         if (requested.contains(name)) {

             throw new IllegalStateException("Requested for second time: " + name);

         }

         requested.add(name);

         byte[] arr = readClass(name);

         /*

         System.err.print("loader['" + name + "'] = [");

         for (int i = 0; i < arr.length; i++) {

         if (i > 0) {

         System.err.print(", ");

         }

         System.err.print(arr[i]);

         }

         System.err.println("]");

          */

         return arr;

     }

     static byte[] readClass(String name) throws IOException {

         URL u = null;

         Enumeration<URL> en = BytesLoader.class.getClassLoader().getResources(name);

         while (en.hasMoreElements()) {

             u = en.nextElement();

         }

         if (u == null) {

             throw new IOException("Can't find " + name);

         }

         try (InputStream is = u.openStream()) {

             byte[] arr;

             arr = new byte[is.available()];

             int offset = 0;

             while (offset < arr.length) {

                 int len = is.read(arr, offset, arr.length - offset);

                 if (len == -1) {

                     throw new IOException("Can't read " + name);

                 }

                 offset += len;

             }

             return arr;

         }

     }

 }