/*
* Copyright 1999-2006 University of Chicago
*
* 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 org.dcache.ftp.client;
/**
* Represents a chunk of data cut out of a larger data volume.
* Buffer is characterized by offset at which it belongs to the
* larger data volume, and length.
* The internal data array always starts at 0 and ends at (length -1).
* Its indexing has nothing to do with offset.
**/
public class Buffer
{
protected final byte[] buf;
protected final int length;
protected final long offset;
/**
* @param buf the data buffer (always starts at 0)
* @param length length of the data in the buffer
*/
public Buffer(byte[] buf, int length)
{
this(buf, length, -1);
}
/**
* @param buf the data buffer (always starts at 0)
* @param length length of the data in the buffer
* @param offset offset of the data the buffer was read from.
*/
public Buffer(byte[] buf, int length, long offset)
{
this.buf = buf;
this.length = length;
this.offset = offset;
}
public byte[] getBuffer()
{
return buf;
}
public int getLength()
{
return length;
}
/**
* Returns offset of the data the buffer was read from.
* Value -1 indicates that offset is not supported.
* For instance, this will happen if the buffer represents
* a chunk of data read off the data channel in the stream
* mode.
*/
public long getOffset()
{
return offset;
}
}