001    /**
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    
018    package org.apache.kahadb.util;
019    
020    public class ByteSequence {
021    
022        public byte[] data;
023        public int offset;
024        public int length;
025    
026        public ByteSequence() {
027        }
028        
029        public ByteSequence(byte data[]) {
030            this.data = data;
031            this.offset = 0;
032            this.length = data.length;
033        }
034    
035        public ByteSequence(byte data[], int offset, int length) {
036            this.data = data;
037            this.offset = offset;
038            this.length = length;
039        }
040    
041        public byte[] getData() {
042            return data;
043        }
044    
045        public int getLength() {
046            return length;
047        }
048    
049        public int getOffset() {
050            return offset;
051        }
052    
053        public void setData(byte[] data) {
054            this.data = data;
055        }
056    
057        public void setLength(int length) {
058            this.length = length;
059        }
060    
061        public void setOffset(int offset) {
062            this.offset = offset;
063        }
064    
065        public void compact() {
066            if (length != data.length) {
067                byte t[] = new byte[length];
068                System.arraycopy(data, offset, t, 0, length);
069                data = t;
070                offset = 0;
071            }
072        }
073    
074        public int indexOf(ByteSequence needle, int pos) {
075            int max = length - needle.length;
076            for (int i = pos; i < max; i++) {
077                if (matches(needle, i)) {
078                    return i;
079                }
080            }
081            return -1;
082        }
083    
084        private boolean matches(ByteSequence needle, int pos) {
085            for (int i = 0; i < needle.length; i++) {
086                if( data[offset + pos+ i] != needle.data[needle.offset + i] ) {
087                    return false;
088                }
089            }
090            return true;
091        }
092    
093        private byte getByte(int i) {
094            return data[offset+i];
095        }
096    
097        final public int indexOf(byte value, int pos) {
098            for (int i = pos; i < length; i++) {
099                if (data[offset + i] == value) {
100                    return i;
101                }
102            }
103            return -1;
104        }
105    }