| /** |
| * 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 org.apache.activemq.util; |
| |
| import java.io.DataInput; |
| import java.io.DataOutput; |
| import java.io.IOException; |
| import java.io.Serializable; |
| |
| /** |
| * Simple BitArray to enable setting multiple boolean values efficently Used |
| * instead of BitSet because BitSet does not allow for efficent serialization. |
| * Will store up to 64 boolean values |
| * |
| * |
| */ |
| public class BitArray implements Serializable { |
| |
| private static final long serialVersionUID = 1L; |
| |
| static final int LONG_SIZE = 64; |
| static final int INT_SIZE = 32; |
| static final int SHORT_SIZE = 16; |
| static final int BYTE_SIZE = 8; |
| private static final long[] BIT_VALUES = {0x0000000000000001L, 0x0000000000000002L, 0x0000000000000004L, |
| 0x0000000000000008L, 0x0000000000000010L, 0x0000000000000020L, |
| 0x0000000000000040L, 0x0000000000000080L, 0x0000000000000100L, |
| 0x0000000000000200L, 0x0000000000000400L, 0x0000000000000800L, |
| 0x0000000000001000L, 0x0000000000002000L, 0x0000000000004000L, |
| 0x0000000000008000L, 0x0000000000010000L, 0x0000000000020000L, |
| 0x0000000000040000L, 0x0000000000080000L, 0x0000000000100000L, |
| 0x0000000000200000L, 0x0000000000400000L, 0x0000000000800000L, |
| 0x0000000001000000L, 0x0000000002000000L, 0x0000000004000000L, |
| 0x0000000008000000L, 0x0000000010000000L, 0x0000000020000000L, |
| 0x0000000040000000L, 0x0000000080000000L, 0x0000000100000000L, |
| 0x0000000200000000L, 0x0000000400000000L, 0x0000000800000000L, |
| 0x0000001000000000L, 0x0000002000000000L, 0x0000004000000000L, |
| 0x0000008000000000L, 0x0000010000000000L, 0x0000020000000000L, |
| 0x0000040000000000L, 0x0000080000000000L, 0x0000100000000000L, |
| 0x0000200000000000L, 0x0000400000000000L, 0x0000800000000000L, |
| 0x0001000000000000L, 0x0002000000000000L, 0x0004000000000000L, |
| 0x0008000000000000L, 0x0010000000000000L, 0x0020000000000000L, |
| 0x0040000000000000L, 0x0080000000000000L, 0x0100000000000000L, |
| 0x0200000000000000L, 0x0400000000000000L, 0x0800000000000000L, |
| 0x1000000000000000L, 0x2000000000000000L, 0x4000000000000000L, |
| 0x8000000000000000L}; |
| private long bits; |
| private int length; |
| |
| /** |
| * @return the length of bits set |
| */ |
| public int length() { |
| return length; |
| } |
| |
| /** |
| * @return the long containing the bits |
| */ |
| public long getBits() { |
| return bits; |
| } |
| |
| /** |
| * set the boolean value at the index |
| * |
| * @param index |
| * @param flag |
| * @return the old value held at this index |
| */ |
| public boolean set(int index, boolean flag) { |
| length = Math.max(length, index + 1); |
| boolean oldValue = (bits & BIT_VALUES[index]) != 0; |
| if (flag) { |
| bits |= BIT_VALUES[index]; |
| } else if (oldValue) { |
| bits &= ~(BIT_VALUES[index]); |
| } |
| return oldValue; |
| } |
| |
| /** |
| * @param index |
| * @return the boolean value at this index |
| */ |
| public boolean get(int index) { |
| return (bits & BIT_VALUES[index]) != 0; |
| } |
| |
| /** |
| * reset all the bit values to false |
| */ |
| public void reset() { |
| bits = 0; |
| } |
| |
| /** |
| * reset all the bits to the value supplied |
| * |
| * @param bits |
| */ |
| public void reset(long bits) { |
| this.bits = bits; |
| } |
| |
| private void writeObject(java.io.ObjectOutputStream out) throws IOException { |
| writeToStream(out); |
| } |
| |
| private void readObject(java.io.ObjectInputStream in) throws IOException, ClassNotFoundException { |
| readFromStream(in); |
| } |
| |
| /** |
| * write the bits to an output stream |
| * |
| * @param dataOut |
| * @throws IOException |
| */ |
| public void writeToStream(DataOutput dataOut) throws IOException { |
| dataOut.writeByte(length); |
| if (length <= BYTE_SIZE) { |
| dataOut.writeByte((byte)bits); |
| } else if (length <= SHORT_SIZE) { |
| dataOut.writeShort((short)bits); |
| } else if (length <= INT_SIZE) { |
| dataOut.writeInt((int)bits); |
| } else { |
| dataOut.writeLong(bits); |
| } |
| } |
| |
| /** |
| * read the bits from an input stream |
| * |
| * @param dataIn |
| * @throws IOException |
| */ |
| public void readFromStream(DataInput dataIn) throws IOException { |
| length = dataIn.readByte(); |
| if (length <= BYTE_SIZE) { |
| bits = dataIn.readByte(); |
| } else if (length <= SHORT_SIZE) { |
| bits = dataIn.readShort(); |
| } else if (length <= INT_SIZE) { |
| bits = dataIn.readInt(); |
| } else { |
| bits = dataIn.readLong(); |
| } |
| } |
| } |