/*
* JBoss, Home of Professional Open Source.
* See the COPYRIGHT.txt file distributed with this work for information
* regarding copyright ownership. Some portions may be licensed
* to Red Hat, Inc. under one or more contributor license agreements.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301 USA.
*/
package org.teiid.common.buffer;
import java.io.IOException;
import java.io.InputStream;
import java.nio.ByteBuffer;
public abstract class ExtensibleBufferedInputStream extends InputStream {
ByteBuffer buf;
@Override
public int read() throws IOException {
if (!ensureBytes()) {
return -1;
}
return buf.get() & 0xff;
}
private boolean ensureBytes() throws IOException {
if (buf == null || buf.remaining() == 0) {
buf = nextBuffer();
if (buf == null) {
return false;
}
}
return true;
}
protected abstract ByteBuffer nextBuffer() throws IOException;
@Override
public int read(byte[] b, int off, int len) throws IOException {
if (!ensureBytes()) {
return -1;
}
len = Math.min(len, buf.remaining());
buf.get(b, off, len);
return len;
}
@Override
public void reset() throws IOException {
if (buf != null) {
buf.rewind();
}
}
public ByteBuffer getBuffer() throws IOException {
if (!ensureBytes()) {
return null;
}
return buf;
}
}