diff --git a/server/src/main/java/org/apache/iotdb/db/utils/BitMap.java b/server/src/main/java/org/apache/iotdb/db/utils/BitMap.java new file mode 100644 index 0000000000000000000000000000000000000000..d62097b8c7d1001e8ae3897af284a2cbe3d0a327 --- /dev/null +++ b/server/src/main/java/org/apache/iotdb/db/utils/BitMap.java @@ -0,0 +1,87 @@ +/* + * 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.iotdb.db.utils; + +import java.util.Arrays; + +public class BitMap { + private static final byte[] BIT_UTIL = new byte[] {1, 2, 4, 8, 16, 32, 64, -128}; + private static final byte[] UNMARK_BIT_UTIL = + new byte[] { + (byte) 0XFE, + (byte) 0XFD, + (byte) 0XFA, + (byte) 0XF7, + (byte) 0XEF, + (byte) 0XDF, + (byte) 0XAF, + (byte) 0X7F + }; + + private byte[] bits; + private int size; + + public BitMap(int size) { + this.size = size; + bits = new byte[size / Byte.SIZE + 1]; + Arrays.fill(bits, (byte) 0); + } + + /** mark as 1 at the given bit position */ + public void mark(int position) { + bits[position / Byte.SIZE] |= BIT_UTIL[position % Byte.SIZE]; + } + + /** mark as 0 at the given bit position */ + public void unmark(int position) { + bits[position / Byte.SIZE] &= UNMARK_BIT_UTIL[position % Byte.SIZE]; + } + + /** whether all bits are one */ + public boolean isAllZero() { + int j; + for (j = 0; j < size / Byte.SIZE; j++) { + if (bits[j] != (byte) 0) { + return false; + } + } + for (j = 0; j < size % Byte.SIZE; j++) { + if ((bits[size / Byte.SIZE] & BIT_UTIL[j]) != BIT_UTIL[j]) { + return false; + } + } + return true; + } + + /** whether all bits are zero */ + public boolean isAllOne() { + int j; + for (j = 0; j < size / Byte.SIZE; j++) { + if (bits[j] != (byte) 0XFF) { + return false; + } + } + for (j = 0; j < size % Byte.SIZE; j++) { + if ((bits[size / Byte.SIZE] & BIT_UTIL[j]) == 0) { + return false; + } + } + return true; + } +}