ByteBufferBackedInputStream.java

/*
 * Copyright (c) 2013, the authors.
 *
 *   This file is part of 'DXFS'.
 *
 *   DXFS is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation, either version 3 of the License, or
 *   (at your option) any later version.
 *
 *   DXFS 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 General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with DXFS.  If not, see <http://www.gnu.org/licenses/>.
 */

package nextflow.fs.dx;

import java.io.IOException;
import java.io.InputStream;
import java.nio.ByteBuffer;

/**
 * An {@code InputStream} adaptor which reads data from a {@code ByteBuffer}
 *
 * See http://stackoverflow.com/a/6603018/395921
 *
 * @author Paolo Di Tommaso <paolo.ditommaso@gmail.com>
 *
 */
class ByteBufferBackedInputStream extends InputStream {

    ByteBuffer buf;

    public ByteBufferBackedInputStream(ByteBuffer buf) {
        this.buf = buf;
    }

    public int read() throws IOException {
        if (!buf.hasRemaining()) {
            return -1;
        }
        return buf.get() & 0xFF;
    }

    public int read(byte[] bytes, int off, int len) throws IOException {
        if (!buf.hasRemaining()) {
            return -1;
        }

        len = Math.min(len, buf.remaining());
        buf.get(bytes, off, len);
        return len;
    }
}