/*
 * 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;

import java.io.IOException;
import java.io.OutputStream;

/**
 * Reference implementation of DataSink. It can be used with non-parallel transfers.
 * It cannot be used with Extended Block Mode because it uses implicit assumption
 * that data arrives in correct sequence. It is not thread safe.
 **/
public class DataSinkStream implements DataSink
{

    protected final OutputStream out;
    protected final boolean autoFlush;
    protected final boolean ignoreOffset;
    protected long offset = 0;

    public DataSinkStream(OutputStream out)
    {
        this(out, false, false);
    }

    public DataSinkStream(OutputStream out,
                          boolean autoFlush,
                          boolean ignoreOffset)
    {
        this.out = out;
        this.autoFlush = autoFlush;
        this.ignoreOffset = ignoreOffset;
    }

    @Override
    public void write(Buffer buffer)
            throws IOException
    {
        long bufOffset = buffer.getOffset();
        if (ignoreOffset ||
            bufOffset == -1 ||
            bufOffset == offset) {
            out.write(buffer.getBuffer(), 0, buffer.getLength());
            if (autoFlush) {
                out.flush();
            }
            offset += buffer.getLength();
        } else {
            throw new IOException("Random offsets not supported.");
        }
    }

    @Override
    public void close()
            throws IOException
    {
        out.close();
    }

}