1 /*

     2  * Copyright (c) 2016, 2018, 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 

    26 package jdk.management.jfr;

    27 

    28 import java.io.BufferedInputStream;

    29 import java.io.Closeable;

    30 import java.io.IOException;

    31 import java.io.InputStream;

    32 

    33 final class Stream implements Closeable {

    34 

    35     private final long identifier;

    36     private final BufferedInputStream inputStream;

    37     private final byte[] buffer;

    38 

    39     private volatile long time;

    40 

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

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

    43         this.identifier = identifier;

    44         this.buffer = new byte[blockSize];

    45     }

    46 

    47     private void touch() {

    48         time = System.currentTimeMillis();

    49     }

    50 

    51     public long getLastTouched() {

    52         return time;

    53     }

    54 

    55     public byte[] read() throws IOException {

    56         // OK to reuse buffer since this

    57         // is only used for serialization

    58         touch();

    59         int read = inputStream.read(buffer);

    60         if (read == -1) {

    61             // null indicate no more data

    62             return null;

    63         }

    64         if (read != buffer.length) {

    65             byte[] smallerBuffer = new byte[read];

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

    67             return smallerBuffer;

    68         }

    69 

    70         return buffer;

    71     }

    72 

    73     @Override

    74     public void close() throws IOException {

    75         inputStream.close();

    76     }

    77 

    78     public long getId() {

    79         return identifier;

    80     }

    81 }