content: /*
   *  This file is part of AndroidIDE.
   *
   *  AndroidIDE 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, either version 3 of the License, or
   *  (at your option) any later version.
   *
   *  AndroidIDE 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 AndroidIDE.  If not, see <https://www.gnu.org/licenses/>.
   */
  
  /*
   * reserved comment block
   * DO NOT REMOVE OR ALTER!
   */
  /*
   * Copyright 2001-2004 The Apache Software Foundation.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  /*
   * $Id: SlotAllocator.java,v 1.2.4.1 2005/09/05 11:32:51 pvedula Exp $
   */
  
  package jaxp.sun.org.apache.xalan.internal.xsltc.compiler.util;
  
  import jaxp.sun.org.apache.bcel.internal.generic.LocalVariableGen;
  import jaxp.sun.org.apache.bcel.internal.generic.Type;
  
  /**
   * @author Jacek Ambroziak
   */
  final class SlotAllocator {
  
      private int   _firstAvailableSlot;
      private int   _size = 8;
      private int   _free = 0;
      private int[] _slotsTaken = new int[_size];
  
      public void initialize(LocalVariableGen[] vars) {
          final int length = vars.length;
          int slot = 0, size, index;
  
          for (int i = 0; i < length; i++) {
              size  = vars[i].getType().getSize();
              index = vars[i].getIndex();
              slot  = Math.max(slot, index + size);
          }
          _firstAvailableSlot = slot;
      }
  
      public int allocateSlot(Type type) {
          final int size = type.getSize();
          final int limit = _free;
          int slot = _firstAvailableSlot, where = 0;
  
          if (_free + size > _size) {
              final int[] array = new int[_size *= 2];
              for (int j = 0; j < limit; j++)
                  array[j] = _slotsTaken[j];
              _slotsTaken = array;
          }
  
          while (where < limit) {
              if (slot + size <= _slotsTaken[where]) {
                  // insert
                  for (int j = limit - 1; j >= where; j--)
                      _slotsTaken[j + size] = _slotsTaken[j];
                  break;
              }
              else {
                  slot = _slotsTaken[where++] + 1;
              }
          }
  
          for (int j = 0; j < size; j++)
              _slotsTaken[where + j] = slot + j;
  
          _free += size;
          return slot;
      }
  
      public void releaseSlot(LocalVariableGen lvg) {
          final int size = lvg.getType().getSize();
          final int slot = lvg.getIndex();
          final int limit = _free;
  
          for (int i = 0; i < limit; i++) {
              if (_slotsTaken[i] == slot) {
                  int j = i + size;
                  while (j < limit) {
                      _slotsTaken[i++] = _slotsTaken[j++];
                  }
                  _free -= size;
                  return;
              }
          }
          String state = "Variable slot allocation error"+
                         "(size="+size+", slot="+slot+", limit="+limit+")";
          ErrorMsg err = new ErrorMsg(ErrorMsg.INTERNAL_ERR, state);
          throw new Error(err.toString());
      }
  }
  