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 018package org.apache.activemq.util; 019 020public 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 int remaining() { return length - offset; } 054 055 public void setData(byte[] data) { 056 this.data = data; 057 } 058 059 public void setLength(int length) { 060 this.length = length; 061 } 062 063 public void setOffset(int offset) { 064 this.offset = offset; 065 } 066 067 public void compact() { 068 if (length != data.length) { 069 byte t[] = new byte[length]; 070 System.arraycopy(data, offset, t, 0, length); 071 data = t; 072 offset = 0; 073 } 074 } 075 076 public void reset() { 077 length = remaining(); 078 if (length > 0) { 079 System.arraycopy(data, offset, data, 0, length); 080 } else { 081 length = 0; 082 } 083 offset = 0; 084 } 085 086 public int indexOf(ByteSequence needle, int pos) { 087 int max = length - needle.length - offset; 088 for (int i = pos; i < max; i++) { 089 if (matches(needle, i)) { 090 return i; 091 } 092 } 093 return -1; 094 } 095 096 private boolean matches(ByteSequence needle, int pos) { 097 for (int i = 0; i < needle.length; i++) { 098 if( data[offset + pos+ i] != needle.data[needle.offset + i] ) { 099 return false; 100 } 101 } 102 return true; 103 } 104 105 private byte getByte(int i) { 106 return data[offset+i]; 107 } 108 109 final public int indexOf(byte value, int pos) { 110 for (int i = pos; i < length; i++) { 111 if (data[offset + i] == value) { 112 return i; 113 } 114 } 115 return -1; 116 } 117 118 public boolean startsWith(final byte[] bytes) { 119 if (length - offset < bytes.length) { 120 return false; 121 } 122 for (int i = 0; i<bytes.length; i++) { 123 if (data[offset+i] != bytes[i]) { 124 return false; 125 } 126 } 127 return true; 128 } 129}