/*
* Copyright (c) 2016 Vivid Solutions.
*
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* and Eclipse Distribution License v. 1.0 which accompanies this distribution.
* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
* and the Eclipse Distribution License is available at
*
* http://www.eclipse.org/org/documents/edl-v10.php.
*/
package org.locationtech.jts.io;
/**
* Allows an array of bytes to be used as an {@link InStream}.
* To optimize memory usage, instances can be reused
* with different byte arrays.
*/
public class ByteArrayInStream
implements InStream
{
/*
* Implementation improvement suggested by Andrea Aime - Dec 15 2007
*/
private byte[] buffer;
private int position;
/**
* Creates a new stream based on the given buffer.
*
* @param buffer the bytes to read
*/
public ByteArrayInStream(final byte[] buffer) {
setBytes(buffer);
}
/**
* Sets this stream to read from the given buffer
*
* @param buffer the bytes to read
*/
public void setBytes(final byte[] buffer) {
this.buffer = buffer;
this.position = 0;
}
/**
* Reads up to <tt>buf.length</tt> bytes from the stream
* into the given byte buffer.
*
* @param buf the buffer to place the read bytes into
*/
public void read(final byte[] buf) {
int numToRead = buf.length;
// don't try and copy past the end of the input
if ((position + numToRead) > buffer.length) {
numToRead = buffer.length - position;
System.arraycopy(buffer, position, buf, 0, numToRead);
// zero out the unread bytes
for (int i = numToRead; i < buf.length; i++) {
buf[i] = 0;
}
}
else {
System.arraycopy(buffer, position, buf, 0, numToRead);
}
position += numToRead;
}
}