/*
 * Copyright (c) 2012, 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.
 *
 * 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
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package com.sun.max.tele.heap;

import com.sun.max.tele.*;
import com.sun.max.tele.heap.region.*;
import com.sun.max.tele.object.*;
import com.sun.max.unsafe.*;

public abstract class RemoteRegionBasedHeapScheme extends AbstractRemoteHeapScheme {

    // TODO (mlvdv) make this a telObject, see TeleRegionTable comments
    protected final TeleRegionTable teleRegionTable;

    public RemoteRegionBasedHeapScheme(TeleVM vm) {
        super(vm);
        teleRegionTable = TeleRegionTable.makeTheTeleRegionTable(vm);
    }


    class GCXHeapRegionInfo implements MaxMemoryManagementInfo {

        final Address address;
        final int regionID;

        GCXHeapRegionInfo(Address address) {
            this.address = address;
            this.regionID =  teleRegionTable.regionID(address);
        }

        // TODO (mlvdv) search through the regions handled by this manager
        public MaxMemoryManagementStatus status() {
            if (regionID < 0) {
                final MaxHeapRegion heapRegion = heap().findHeapRegion(address);
                if (heapRegion == null) {
                    // The location is not in any memory region allocated by the heap.
                    return MaxMemoryManagementStatus.NONE;
                }
            }
             // Unclear what the semantics of this should be during GC.
            // We should be able to tell past the marking phase if an address point to a live object.
            // But what about during the marking phase ? The only thing that can be told is that
            // what was dead before marking begin should still be dead during marking.

            // TODO (ld) This requires the inspector to know intimately about the heap structures.
            // The current MS scheme  linearly allocate over chunk of free space discovered during the past MS.
            // However, it doesn't maintain these as "linearly allocating memory region". This could be done by formatting
            // all reusable free space as such (instead of the chunk of free list as is done now). in any case.

            return MaxMemoryManagementStatus.LIVE;
        }

        public String terseInfo() {
            return regionID < 0 ? "-" : "region #" + regionID;
        }

        public String shortDescription() {
            // Laurent: more information could be added here, will appear in tooltip
            return vm().heapScheme().name();
        }

        public Address address() {
            return address;
        }

        public TeleObject tele() {
            if (regionID < 0) {
                return null;
            }
            return objects().findObjectAt(teleRegionTable.regionInfo(regionID));
        }
    }

    public MaxMemoryManagementInfo getMemoryManagementInfo(final Address address) {
        return new GCXHeapRegionInfo(address);
    }

    /**
     * Gets the heap region tag's name for the specified tag.
     *
     * @param tag a valid region tag used by this heap scheme
     * @return a textual representation of the tag, or the empty string if the tag is invalid or if the heap scheme doesn't tag its regions
     */
    public String tagName(int tag) {
        return "";
    }

}