J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2005 Sun Microsystems, Inc. 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. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | |
| 27 | /* |
| 28 | * The contents of this file are subject to the Sun Public License |
| 29 | * Version 1.0 (the "License"); you may not use this file except in |
| 30 | * compliance with the License. A copy of the License is available at |
| 31 | * http://www.sun.com/, and in the file LICENSE.html in the |
| 32 | * doc directory. |
| 33 | * |
| 34 | * The Original Code is HAT. The Initial Developer of the |
| 35 | * Original Code is Bill Foote, with contributions from others |
| 36 | * at JavaSoft/Sun. Portions created by Bill Foote and others |
| 37 | * at Javasoft/Sun are Copyright (C) 1997-2004. All Rights Reserved. |
| 38 | * |
| 39 | * In addition to the formal license, I ask that you don't |
| 40 | * change the history or donations files without permission. |
| 41 | * |
| 42 | */ |
| 43 | |
| 44 | package com.sun.tools.hat.internal.model; |
| 45 | |
| 46 | import java.io.File; |
| 47 | import java.io.FileInputStream; |
| 48 | import java.io.InputStreamReader; |
| 49 | import java.io.Reader; |
| 50 | import java.io.BufferedReader; |
| 51 | import java.io.IOException; |
| 52 | |
| 53 | import java.util.Hashtable; |
| 54 | |
| 55 | /** |
| 56 | * This represents a set of data members that should be excluded from the |
| 57 | * reachable objects query. |
| 58 | * This is useful to exclude observers from the |
| 59 | * transitive closure of objects reachable from a given object, allowing |
| 60 | * some kind of real determination of the "size" of that object. |
| 61 | * |
| 62 | * @author Bill Foote |
| 63 | */ |
| 64 | public class ReachableExcludesImpl implements ReachableExcludes { |
| 65 | |
| 66 | private File excludesFile; |
| 67 | private long lastModified; |
| 68 | private Hashtable methods; // Hashtable<String, String>, used as a bag |
| 69 | |
| 70 | /** |
| 71 | * Create a new ReachableExcludesImpl over the given file. The file will be |
| 72 | * re-read whenever the timestamp changes. |
| 73 | */ |
| 74 | public ReachableExcludesImpl(File excludesFile) { |
| 75 | this.excludesFile = excludesFile; |
| 76 | readFile(); |
| 77 | } |
| 78 | |
| 79 | private void readFileIfNeeded() { |
| 80 | if (excludesFile.lastModified() != lastModified) { |
| 81 | synchronized(this) { |
| 82 | if (excludesFile.lastModified() != lastModified) { |
| 83 | readFile(); |
| 84 | } |
| 85 | } |
| 86 | } |
| 87 | } |
| 88 | |
| 89 | private void readFile() { |
| 90 | long lm = excludesFile.lastModified(); |
| 91 | Hashtable<String, String> m = new Hashtable<String, String>(); |
| 92 | |
| 93 | try { |
| 94 | BufferedReader r = new BufferedReader(new InputStreamReader( |
| 95 | new FileInputStream(excludesFile))); |
| 96 | |
| 97 | String method; |
| 98 | while ((method = r.readLine()) != null) { |
| 99 | m.put(method, method); |
| 100 | } |
| 101 | lastModified = lm; |
| 102 | methods = m; // We want this to be atomic |
| 103 | } catch (IOException ex) { |
| 104 | System.out.println("Error reading " + excludesFile + ": " + ex); |
| 105 | } |
| 106 | } |
| 107 | |
| 108 | /** |
| 109 | * @return true iff the given field is on the histlist of excluded |
| 110 | * fields. |
| 111 | */ |
| 112 | public boolean isExcluded(String fieldName) { |
| 113 | readFileIfNeeded(); |
| 114 | return methods.get(fieldName) != null; |
| 115 | } |
| 116 | } |