/*

 * Copyright (c) 1997, 2008, Oracle and/or its affiliates. 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.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

/*

 * The Original Code is HAT. The Initial Developer of the

 * Original Code is Bill Foote, with contributions from others

 * at JavaSoft/Sun.

 */

package com.sun.tools.hat.internal.model;

import java.util.Vector;

import java.util.Hashtable;

import java.util.Enumeration;

import com.sun.tools.hat.internal.util.ArraySorter;

import com.sun.tools.hat.internal.util.Comparer;

/**

 * @author      A. Sundararajan

 */

public class ReachableObjects {

    public ReachableObjects(JavaHeapObject root,

                            final ReachableExcludes excludes) {

        this.root = root;

        final Hashtable<JavaHeapObject, JavaHeapObject> bag = new Hashtable<JavaHeapObject, JavaHeapObject>();

        final Hashtable<String, String> fieldsExcluded = new Hashtable<String, String>();  //Bag<String>

        final Hashtable<String, String> fieldsUsed = new Hashtable<String, String>();   // Bag<String>

        JavaHeapObjectVisitor visitor = new AbstractJavaHeapObjectVisitor() {

            public void visit(JavaHeapObject t) {

                // Size is zero for things like integer fields

                if (t != null && t.getSize() > 0 && bag.get(t) == null) {

                    bag.put(t, t);

                    t.visitReferencedObjects(this);

                }

            }

            public boolean mightExclude() {

                return excludes != null;

            }

            public boolean exclude(JavaClass clazz, JavaField f) {

                if (excludes == null) {

                    return false;

                }

                String nm = clazz.getName() + "." + f.getName();

                if (excludes.isExcluded(nm)) {

                    fieldsExcluded.put(nm, nm);

                    return true;

                } else {

                    fieldsUsed.put(nm, nm);

                    return false;

                }

            }

        };

        // Put the closure of root and all objects reachable from root into

        // bag (depth first), but don't include root:

        visitor.visit(root);

        bag.remove(root);

        // Now grab the elements into a vector, and sort it in decreasing size

        JavaThing[] things = new JavaThing[bag.size()];

        int i = 0;

        for (Enumeration e = bag.elements(); e.hasMoreElements(); ) {

            things[i++] = (JavaThing) e.nextElement();

        }

        ArraySorter.sort(things, new Comparer() {

            public int compare(Object lhs, Object rhs) {

                JavaThing left = (JavaThing) lhs;

                JavaThing right = (JavaThing) rhs;

                int diff = right.getSize() - left.getSize();

                if (diff != 0) {

                    return diff;

                }

                return left.compareTo(right);

            }

        });

        this.reachables = things;

        this.totalSize = root.getSize();

        for (i = 0; i < things.length; i++) {

            this.totalSize += things[i].getSize();

        }

        excludedFields = getElements(fieldsExcluded);

        usedFields = getElements(fieldsUsed);

    }

    public JavaHeapObject getRoot() {

        return root;

    }

    public JavaThing[] getReachables() {

        return reachables;

    }

    public long getTotalSize() {

        return totalSize;

    }

    public String[] getExcludedFields() {

        return excludedFields;

    }

    public String[] getUsedFields() {

        return usedFields;

    }

    private String[] getElements(Hashtable ht) {

        Object[] keys = ht.keySet().toArray();

        int len = keys.length;

        String[] res = new String[len];

        System.arraycopy(keys, 0, res, 0, len);

        ArraySorter.sortArrayOfStrings(res);

        return res;

    }

    private JavaHeapObject root;

    private JavaThing[] reachables;

    private String[]  excludedFields;

    private String[]  usedFields;

    private long totalSize;

}