1 /*

     2  * Copyright (c) 1996, Oracle and/or its affiliates. All rights reserved.

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

     4  *

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

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

     7  * published by the Free Software Foundation.  Oracle designates this

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

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

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

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

    15  * accompanied this code).

    16  *

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

    18  * 2 along with this work; if not, write to the Free Software Foundation,

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

    20  *

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

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

    23  * questions.

    24  */

    25 package sun.rmi.transport.proxy;

    26 

    27 import java.io.*;

    28 

    29 /**

    30  * The HttpSendInputStream class is used by the HttpSendSocket class as

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

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

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

    34  */

    35 class HttpSendInputStream extends FilterInputStream {

    36 

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

    38     HttpSendSocket owner;

    39 

    40     /**

    41      * Create new filter on a given input stream.

    42      * @param in the InputStream to filter from

    43      * @param owner the HttpSendSocket that is providing this stream

    44      */

    45     public HttpSendInputStream(InputStream in, HttpSendSocket owner)

    46         throws IOException

    47     {

    48         super(in);

    49 

    50         this.owner = owner;

    51     }

    52 

    53     /**

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

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

    56      * input stream obtained.

    57      */

    58     public void deactivate()

    59     {

    60         in = null;

    61     }

    62 

    63     /**

    64      * Read a byte of data from the stream.

    65      */

    66     public int read() throws IOException

    67     {

    68         if (in == null)

    69             in = owner.readNotify();

    70         return in.read();

    71     }

    72 

    73     /**

    74      * Read into an array of bytes.

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

    76      * @param off the start offset of the data

    77      * @param len the maximum number of bytes to read

    78      */

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

    80     {

    81         if (len == 0)

    82             return 0;

    83         if (in == null)

    84             in = owner.readNotify();

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

    86     }

    87 

    88     /**

    89      * Skip bytes of input.

    90      * @param n the number of bytes to be skipped

    91      */

    92     public long skip(long n) throws IOException

    93     {

    94         if (n == 0)

    95             return 0;

    96         if (in == null)

    97             in = owner.readNotify();

    98         return in.skip(n);

    99     }

   100 

   101     /**

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

   103      */

   104     public int available() throws IOException

   105     {

   106         if (in == null)

   107             in = owner.readNotify();

   108         return in.available();

   109     }

   110 

   111     /**

   112      * Close the stream.

   113      */

   114     public void close() throws IOException

   115     {

   116         owner.close();

   117     }

   118 

   119     /**

   120      * Mark the current position in the stream.

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

   122      */

   123     public synchronized void mark(int readlimit)

   124     {

   125         if (in == null) {

   126             try {

   127                 in = owner.readNotify();

   128             }

   129             catch (IOException e) {

   130                 return;

   131             }

   132         }

   133         in.mark(readlimit);

   134     }

   135 

   136     /**

   137      * Reposition the stream to the last marked position.

   138      */

   139     public synchronized void reset() throws IOException

   140     {

   141         if (in == null)

   142             in = owner.readNotify();

   143         in.reset();

   144     }

   145 

   146     /**

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

   148      */

   149     public boolean markSupported()

   150     {

   151         if (in == null) {

   152             try {

   153                 in = owner.readNotify();

   154             }

   155             catch (IOException e) {

   156                 return false;

   157             }

   158         }

   159         return in.markSupported();

   160     }

   161 }