/*

 * Copyright (c) 2016, 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

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 */

package jdk.jshell.execution;

import java.io.DataInputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import java.util.Map;

/**

 * Read from an InputStream which has been packetized and write its contents

 * to the named OutputStreams.

 *

 * @author Jan Lahoda

 * @see Util#demultiplexInput(java.io.InputStream, java.io.OutputStream, java.io.OutputStream, java.io.OutputStream...)

 */

class DemultiplexInput extends Thread {

    private final DataInputStream delegate;

    private final Map<String, OutputStream> io;

    private final Iterable<OutputStream> closeList;

    DemultiplexInput(InputStream input, Map<String, OutputStream> io, Iterable<OutputStream> closeList) {

        super("output reader");

        setDaemon(true);

        this.delegate = new DataInputStream(input);

        this.io = io;

        this.closeList = closeList;

    }

    @Override

    public void run() {

        try {

            while (true) {

                int nameLen = delegate.read();

                if (nameLen == (-1)) {

                    break;

                }

                byte[] name = new byte[nameLen];

                DemultiplexInput.this.delegate.readFully(name);

                int dataLen = delegate.read();

                byte[] data = new byte[dataLen];

                DemultiplexInput.this.delegate.readFully(data);

                String chan = new String(name, "UTF-8");

                OutputStream out = io.get(chan);

                if (out == null) {

                    debug("Unexpected channel name: %s", chan);

                } else {

                    out.write(data);

                }

            }

        } catch (IOException ex) {

            debug(ex, "Failed reading output");

        } finally {

            for (OutputStream out : closeList) {

                try {

                    out.close();

                } catch (IOException ex) {

                    debug(ex, "Failed reading output");

                }

            }

        }

    }

    /**

     * Log debugging information. Arguments as for {@code printf}.

     *

     * @param format a format string as described in Format string syntax

     * @param args arguments referenced by the format specifiers in the format

     * string.

     */

    private void debug(String format, Object... args) {

        // Reserved for future logging

    }

    /**

     * Log a serious unexpected internal exception.

     *

     * @param ex the exception

     * @param where a description of the context of the exception

     */

    private void debug(Throwable ex, String where) {

        // Reserved for future logging

    }

}