--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/com/sun/tools/hat/internal/model/ReachableExcludesImpl.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,116 @@
+/*
+ * Copyright 2005 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+
+/*
+ * The contents of this file are subject to the Sun Public License
+ * Version 1.0 (the "License"); you may not use this file except in
+ * compliance with the License. A copy of the License is available at
+ * http://www.sun.com/, and in the file LICENSE.html in the
+ * doc directory.
+ *
+ * The Original Code is HAT. The Initial Developer of the
+ * Original Code is Bill Foote, with contributions from others
+ * at JavaSoft/Sun. Portions created by Bill Foote and others
+ * at Javasoft/Sun are Copyright (C) 1997-2004. All Rights Reserved.
+ *
+ * In addition to the formal license, I ask that you don't
+ * change the history or donations files without permission.
+ *
+ */
+
+package com.sun.tools.hat.internal.model;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.InputStreamReader;
+import java.io.Reader;
+import java.io.BufferedReader;
+import java.io.IOException;
+
+import java.util.Hashtable;
+
+/**
+ * This represents a set of data members that should be excluded from the
+ * reachable objects query.
+ * This is useful to exclude observers from the
+ * transitive closure of objects reachable from a given object, allowing
+ * some kind of real determination of the "size" of that object.
+ *
+ * @author      Bill Foote
+ */
+public class ReachableExcludesImpl implements ReachableExcludes {
+
+    private File excludesFile;
+    private long lastModified;
+    private Hashtable methods;  // Hashtable<String, String>, used as a bag
+
+    /**
+     * Create a new ReachableExcludesImpl over the given file.  The file will be
+     * re-read whenever the timestamp changes.
+     */
+    public ReachableExcludesImpl(File excludesFile) {
+        this.excludesFile = excludesFile;
+        readFile();
+    }
+
+    private void readFileIfNeeded() {
+        if (excludesFile.lastModified() != lastModified) {
+            synchronized(this) {
+                if (excludesFile.lastModified() != lastModified) {
+                    readFile();
+                }
+            }
+        }
+    }
+
+    private void readFile() {
+        long lm = excludesFile.lastModified();
+        Hashtable<String, String> m = new Hashtable<String, String>();
+
+        try {
+            BufferedReader r = new BufferedReader(new InputStreamReader(
+                                    new FileInputStream(excludesFile)));
+
+            String method;
+            while ((method = r.readLine()) != null) {
+                m.put(method, method);
+            }
+            lastModified = lm;
+            methods = m;        // We want this to be atomic
+        } catch (IOException ex) {
+            System.out.println("Error reading " + excludesFile + ":  " + ex);
+        }
+    }
+
+    /**
+     * @return true iff the given field is on the histlist of excluded
+     *          fields.
+     */
+    public boolean isExcluded(String fieldName) {
+        readFileIfNeeded();
+        return methods.get(fieldName) != null;
+    }
+}