/*

 * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package jdk.management.jfr;

import java.io.BufferedInputStream;

import java.io.Closeable;

import java.io.IOException;

import java.io.InputStream;

final class Stream implements Closeable {

    private final long identifier;

    private final BufferedInputStream inputStream;

    private final byte[] buffer;

    private volatile long time;

    Stream(InputStream is, long identifier, int blockSize) {

        this.inputStream = new BufferedInputStream(is, 50000);

        this.identifier = identifier;

        this.buffer = new byte[blockSize];

    }

    private void touch() {

        time = System.currentTimeMillis();

    }

    public long getLastTouched() {

        return time;

    }

    public byte[] read() throws IOException {

        // OK to reuse buffer since this

        // is only used for serialization

        touch();

        int read = inputStream.read(buffer);

        if (read == -1) {

            // null indicate no more data

            return null;

        }

        if (read != buffer.length) {

            byte[] smallerBuffer = new byte[read];

            System.arraycopy(buffer, 0, smallerBuffer, 0, read);

            return smallerBuffer;

        }

        return buffer;

    }

    @Override

    public void close() throws IOException {

        inputStream.close();

    }

    public long getId() {

        return identifier;

    }

}