/*
* 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.dqp.internal.process;
import java.io.IOException;
import java.io.InputStream;
import java.io.PushbackInputStream;
import org.teiid.client.lob.LobChunk;
import org.teiid.client.lob.LobChunkProducer;
import org.teiid.core.CorePlugin;
/**
* A wrapper class, given a InputStream object can convert a underlying
* stream into sequence of ByteLobChunk objects of given chunk size.
*/
public class ByteLobChunkStream implements LobChunkProducer {
private PushbackInputStream stream;
private int chunkSize;
private boolean closed;
public ByteLobChunkStream(InputStream stream, int chunkSize) {
this.stream = new PushbackInputStream(stream);
this.chunkSize = chunkSize;
}
public LobChunk getNextChunk() throws IOException{
if (this.closed) {
throw new IllegalStateException(CorePlugin.Util.getString("stream_closed")); //$NON-NLS-1$
}
// read contents from the stream
byte[] cbuf = new byte[this.chunkSize];
int read = this.stream.read(cbuf);
if (read == -1) {
return new LobChunk(new byte[0], true);
}
boolean isLast = false;
if (read != this.chunkSize) {
byte[] buf = new byte[read];
System.arraycopy(cbuf, 0, buf, 0, read);
cbuf = buf;
}
int next = this.stream.read();
if (next == -1) {
isLast = true;
} else {
this.stream.unread(next);
}
return new LobChunk(cbuf, isLast);
}
public void close() throws IOException {
this.closed = true;
this.stream.close();
}
}