content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You 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.
   */
  
  package mf.org.apache.xerces.impl.dtd.models;
  
  
  /**
   * This class is a very simple bitset class. The DFA content model code needs
   * to support a bit set, but the java BitSet class is way, way overkill. Our
   * bitset never needs to be expanded after creation, hash itself, etc...
   * <p/>
   * Since the vast majority of content models will never require more than 64
   * bits, and since allocation of anything in Java is expensive, this class
   * provides a hybrid implementation that uses two ints for instances that use
   * 64 bits or fewer. It has a byte array reference member which will only be
   * used if more than 64 bits are required.
   * <p/>
   * Note that the code that uses this class will never perform operations
   * on sets of different sizes, so that check does not have to be made here.
   *
   * @version $Id: CMStateSet.java 446752 2006-09-15 21:55:19Z mrglavas $
   * @xerces.internal
   */
  // made this class public so it can be accessed by
  // the XS content models from the schema package -neilg.
  public class CMStateSet {
      // -------------------------------------------------------------------
      //  Private data members
      //
      //  fBitCount
      //      The count of bits that the outside world wants to support,
      //      so its the max bit index plus one.
      //
      //  fByteCount
      //      If the bit count is > 64, then we use the fByteArray member to
      //      store the bits, and this indicates its size in bytes. Otherwise
      //      its value is meaningless.
      //
      //  fBits1
      //  fBits2
      //      When the bit count is < 64 (very common), these hold the bits.
      //      Otherwise, the fByteArray member holds htem.
      // -------------------------------------------------------------------
      int fBitCount;
      int fByteCount;
      int fBits1;
      int fBits2;
      byte[] fByteArray;
  
      // -------------------------------------------------------------------
      //  Constructors
      // -------------------------------------------------------------------
      public CMStateSet(int bitCount) {
          // Store the required bit count and insure its legal
          fBitCount = bitCount;
          if (fBitCount < 0)
              throw new RuntimeException("ImplementationMessages.VAL_CMSI");
  
          //
          //  See if we need to allocate the byte array or whether we can live
          //  within the 64 bit high performance scheme.
          //
          if (fBitCount > 64) {
              fByteCount = fBitCount / 8;
              if (fBitCount % 8 != 0)
                  fByteCount++;
              fByteArray = new byte[fByteCount];
          }
  
          // Init all the bits to zero
          zeroBits();
      }
  
      // -------------------------------------------------------------------
      //  Public inherited methods
      // -------------------------------------------------------------------
      @Override
      public String toString() {
          StringBuffer strRet = new StringBuffer();
          try {
              strRet.append('{');
              for (int index = 0; index < fBitCount; index++) {
                  if (getBit(index)) {
                      strRet.append(' ').append(index);
                  }
              }
              strRet.append(" }");
          } catch (RuntimeException exToCatch) {
              //
              //  We know this won't happen but we have to catch it to avoid it
              //  having to be in our 'throws' list.
              //
          }
          return strRet.toString();
      }
  
      // -------------------------------------------------------------------
      //  Package final methods
      // -------------------------------------------------------------------
  // the XS content models from the schema package -neilg.
      public final void intersection(CMStateSet setToAnd) {
          if (fBitCount < 65) {
              fBits1 &= setToAnd.fBits1;
              fBits2 &= setToAnd.fBits2;
          } else {
              for (int index = fByteCount - 1; index >= 0; index--)
                  fByteArray[index] &= setToAnd.fByteArray[index];
          }
      }
  
      public final boolean getBit(int bitToGet) {
          if (bitToGet >= fBitCount)
              throw new RuntimeException("ImplementationMessages.VAL_CMSI");
  
          if (fBitCount < 65) {
              final int mask = (0x1 << (bitToGet % 32));
              if (bitToGet < 32)
                  return (fBits1 & mask) != 0;
              else
                  return (fBits2 & mask) != 0;
          } else {
              // Create the mask and byte values
              final byte mask = (byte) (0x1 << (bitToGet % 8));
              final int ofs = bitToGet >> 3;
  
              // And access the right bit and byte
              return ((fByteArray[ofs] & mask) != 0);
          }
      }
  
      public final boolean isEmpty() {
          if (fBitCount < 65) {
              return ((fBits1 == 0) && (fBits2 == 0));
          } else {
              for (int index = fByteCount - 1; index >= 0; index--) {
                  if (fByteArray[index] != 0)
                      return false;
              }
          }
          return true;
      }
  
      final boolean isSameSet(CMStateSet setToCompare) {
          if (fBitCount != setToCompare.fBitCount)
              return false;
  
          if (fBitCount < 65) {
              return ((fBits1 == setToCompare.fBits1)
                      && (fBits2 == setToCompare.fBits2));
          }
  
          for (int index = fByteCount - 1; index >= 0; index--) {
              if (fByteArray[index] != setToCompare.fByteArray[index])
                  return false;
          }
          return true;
      }
  
      // the XS content models from the schema package -neilg.
      public final void union(CMStateSet setToOr) {
          if (fBitCount < 65) {
              fBits1 |= setToOr.fBits1;
              fBits2 |= setToOr.fBits2;
          } else {
              for (int index = fByteCount - 1; index >= 0; index--)
                  fByteArray[index] |= setToOr.fByteArray[index];
          }
      }
  
      public final void setBit(int bitToSet) {
          if (bitToSet >= fBitCount)
              throw new RuntimeException("ImplementationMessages.VAL_CMSI");
  
          if (fBitCount < 65) {
              final int mask = (0x1 << (bitToSet % 32));
              if (bitToSet < 32) {
                  fBits1 &= ~mask;
                  fBits1 |= mask;
              } else {
                  fBits2 &= ~mask;
                  fBits2 |= mask;
              }
          } else {
              // Create the mask and byte values
              final byte mask = (byte) (0x1 << (bitToSet % 8));
              final int ofs = bitToSet >> 3;
  
              // And access the right bit and byte
              fByteArray[ofs] &= ~mask;
              fByteArray[ofs] |= mask;
          }
      }
  
      // the XS content models from the schema package -neilg.
      public final void setTo(CMStateSet srcSet) {
          // They have to be the same size
          if (fBitCount != srcSet.fBitCount)
              throw new RuntimeException("ImplementationMessages.VAL_CMSI");
  
          if (fBitCount < 65) {
              fBits1 = srcSet.fBits1;
              fBits2 = srcSet.fBits2;
          } else {
              for (int index = fByteCount - 1; index >= 0; index--)
                  fByteArray[index] = srcSet.fByteArray[index];
          }
      }
  
      // had to make this method public so it could be accessed from
      // schema package - neilg.
      public final void zeroBits() {
          if (fBitCount < 65) {
              fBits1 = 0;
              fBits2 = 0;
          } else {
              for (int index = fByteCount - 1; index >= 0; index--)
                  fByteArray[index] = 0;
          }
      }
  
      /* Optimization(Jan, 2001) */
      @Override
      public boolean equals(Object o) {
          if (!(o instanceof CMStateSet)) return false;
          return isSameSet((CMStateSet) o);
      }
  
      @Override
      public int hashCode() {
          if (fBitCount < 65) {
              return fBits1 + fBits2 * 31;
          } else {
              int hash = 0;
              for (int index = fByteCount - 1; index >= 0; index--)
                  hash = fByteArray[index] + hash * 31;
              return hash;
          }
      }
     /* Optimization(Jan, 2001) */
  }
  