/*

 * Copyright (c) 1996, 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 sun.rmi.transport.proxy;

import java.io.*;

/**

 * The HttpSendInputStream class is used by the HttpSendSocket class as

 * a layer on the top of the InputStream it returns so that it can be

 * notified of attempts to read from it.  This allows the HttpSendSocket

 * to know when it should push across its output message.

 */

class HttpSendInputStream extends FilterInputStream {

    /** the HttpSendSocket object that is providing this stream */

    HttpSendSocket owner;

    /**

     * Create new filter on a given input stream.

     * @param in the InputStream to filter from

     * @param owner the HttpSendSocket that is providing this stream

     */

    public HttpSendInputStream(InputStream in, HttpSendSocket owner)

        throws IOException

    {

        super(in);

        this.owner = owner;

    }

    /**

     * Mark this stream as inactive for its owner socket, so the next time

     * a read is attempted, the owner will be notified and a new underlying

     * input stream obtained.

     */

    public void deactivate()

    {

        in = null;

    }

    /**

     * Read a byte of data from the stream.

     */

    public int read() throws IOException

    {

        if (in == null)

            in = owner.readNotify();

        return in.read();

    }

    /**

     * Read into an array of bytes.

     * @param b the buffer into which the data is to be read

     * @param off the start offset of the data

     * @param len the maximum number of bytes to read

     */

    public int read(byte b[], int off, int len) throws IOException

    {

        if (len == 0)

            return 0;

        if (in == null)

            in = owner.readNotify();

        return in.read(b, off, len);

    }

    /**

     * Skip bytes of input.

     * @param n the number of bytes to be skipped

     */

    public long skip(long n) throws IOException

    {

        if (n == 0)

            return 0;

        if (in == null)

            in = owner.readNotify();

        return in.skip(n);

    }

    /**

     * Return the number of bytes that can be read without blocking.

     */

    public int available() throws IOException

    {

        if (in == null)

            in = owner.readNotify();

        return in.available();

    }

    /**

     * Close the stream.

     */

    public void close() throws IOException

    {

        owner.close();

    }

    /**

     * Mark the current position in the stream.

     * @param readlimit how many bytes can be read before mark becomes invalid

     */

    public synchronized void mark(int readlimit)

    {

        if (in == null) {

            try {

                in = owner.readNotify();

            }

            catch (IOException e) {

                return;

            }

        }

        in.mark(readlimit);

    }

    /**

     * Reposition the stream to the last marked position.

     */

    public synchronized void reset() throws IOException

    {

        if (in == null)

            in = owner.readNotify();

        in.reset();

    }

    /**

     * Return true if this stream type supports mark/reset.

     */

    public boolean markSupported()

    {

        if (in == null) {

            try {

                in = owner.readNotify();

            }

            catch (IOException e) {

                return false;

            }

        }

        return in.markSupported();

    }

}