custom-board-bundle-sample-.../java_console/io/src/etch/util/CircularByteBuffer.java

89 lines
1.9 KiB
Java

/* $Id$
*
* Copyright 2007-2008 Cisco Systems Inc.
*
* Licensed 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 etch.util;
import net.jcip.annotations.NotThreadSafe;
import java.io.EOFException;
import java.nio.BufferOverflowException;
/**
* Description of CircularByteBuffer.
*/
@NotThreadSafe
public class CircularByteBuffer extends ByteBuffer {
/**
* Constructs the CircularByteBuffer.
*
* @param size
*/
public CircularByteBuffer(int size) {
this.size = size;
buf = new byte[size];
}
private final int size;
private final byte[] buf;
private int length;
private int nextGet;
private int nextPut;
@Override
public int size() {
return size;
}
@Override
public int length() {
return length;
}
@Override
public void clear() {
length = 0;
nextGet = 0;
nextPut = 0;
}
@Override
public byte get() throws EOFException {
if (isEmpty())
throw new EOFException();
length--;
byte b = buf[nextGet++];
if (nextGet >= size)
nextGet = 0;
return b;
}
@Override
public void put(byte b) throws BufferOverflowException {
if (isFull())
throw new BufferOverflowException();
length++;
buf[nextPut++] = b;
if (nextPut >= size)
nextPut = 0;
}
}