1 /* 2 * Copyright (c) 2016, 2019, 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 }