Reader.java revision 2224:2a8815d86b93 
1/*
2 * Copyright (c) 1997, 2016, 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
27/*
28 * The Original Code is HAT. The Initial Developer of the
29 * Original Code is Bill Foote, with contributions from others
30 * at JavaSoft/Sun.
31 */
32
33package jdk.test.lib.hprof.parser;
34
35import java.io.*;
36import jdk.test.lib.hprof.model.*;
37
38/**
39 * Abstract base class for reading object dump files.  A reader need not be
40 * thread-safe.
41 *
42 * @author      Bill Foote
43 */
44
45
46public abstract class Reader {
47    protected PositionDataInputStream in;
48
49    protected Reader(PositionDataInputStream in) {
50        this.in = in;
51    }
52
53    /**
54     * Read a snapshot from a data input stream.  It is assumed that the magic
55     * number has already been read.
56     */
57    abstract public Snapshot read() throws IOException;
58
59    /**
60     * Read a snapshot from a file.
61     *
62     * @param heapFile The name of a file containing a heap dump
63     * @param callStack If true, read the call stack of allocaation sites
64     */
65    public static Snapshot readFile(String heapFile, boolean callStack,
66                                    int debugLevel)
67            throws IOException {
68        int dumpNumber = 1;
69        int pos = heapFile.lastIndexOf('#');
70        if (pos > -1) {
71            String num = heapFile.substring(pos+1, heapFile.length());
72            try {
73                dumpNumber = Integer.parseInt(num, 10);
74            } catch (java.lang.NumberFormatException ex) {
75                String msg = "In file name \"" + heapFile
76                             + "\", a dump number was "
77                             + "expected after the :, but \""
78                             + num + "\" was found instead.";
79                System.err.println(msg);
80                throw new IOException(msg);
81            }
82            heapFile = heapFile.substring(0, pos);
83        }
84        try (PositionDataInputStream in = new PositionDataInputStream(
85                new BufferedInputStream(new FileInputStream(heapFile)))) {
86            int i = in.readInt();
87            if (i == HprofReader.MAGIC_NUMBER) {
88                Reader r
89                    = new HprofReader(heapFile, in, dumpNumber,
90                                      callStack, debugLevel);
91                return r.read();
92            } else {
93                throw new IOException("Unrecognized magic number: " + i);
94            }
95        }
96    }
97}
98