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 org.apache.activemq.util;
  
  import java.util.Arrays;
  
  public class ByteSequence {
  
      public byte[] data;
      public int offset;
      public int length;
  
      public ByteSequence() {
      }
  
      public ByteSequence(byte data[]) {
          this.data = data;
          this.offset = 0;
          this.length = data.length;
      }
  
      public ByteSequence(byte data[], int offset, int length) {
          this.data = data;
          this.offset = offset;
          this.length = length;
      }
  
      public byte[] getData() {
          return data;
      }
  
      public int getLength() {
          return length;
      }
  
      public int getOffset() {
          return offset;
      }
  
      public int remaining() { return length - offset; }
  
      public void setData(byte[] data) {
          this.data = data;
      }
  
      public void setLength(int length) {
          this.length = length;
      }
  
      public void setOffset(int offset) {
          this.offset = offset;
      }
  
      public void compact() {
          if (length != data.length) {
              byte t[] = new byte[length];
              System.arraycopy(data, offset, t, 0, length);
              data = t;
              offset = 0;
          }
      }
  
      public void reset() {
          length = remaining();
          if (length > 0) {
              System.arraycopy(data, offset, data, 0, length);
          } else {
              length = 0;
          }
          offset = 0;
      }
  
      public int indexOf(ByteSequence needle, int pos) {
          int max = length - needle.length - offset;
          for (int i = pos; i < max; i++) {
              if (matches(needle, i)) {
                  return i;
              }
          }
          return -1;
      }
  
      private boolean matches(ByteSequence needle, int pos) {
          for (int i = 0; i < needle.length; i++) {
              if( data[offset + pos+ i] != needle.data[needle.offset + i] ) {
                  return false;
              }
          }
          return true;
      }
  
      private byte getByte(int i) {
          return data[offset+i];
      }
  
      final public int indexOf(byte value, int pos) {
          for (int i = pos; i < length; i++) {
              if (data[offset + i] == value) {
                  return i;
              }
          }
          return -1;
      }
  
      public boolean startsWith(final byte[] bytes) {
          if (length - offset < bytes.length) {
              return false;
          }
          for (int i = 0; i<bytes.length; i++) {
              if (data[offset+i] != bytes[i]) {
                  return false;
              }
          }
          return true;
      }
  
      /**
       * Makes a deep copy of the data into a new byte array
       * starting at the offset.
       *
       * @return
       */
      public byte[] toArray() {
          return Arrays.copyOfRange(getData(), getOffset(), getLength());
      }
  }
  