/*-
 * See the file LICENSE for redistribution information.
 *
 * Copyright (c) 2002,2008 Oracle.  All rights reserved.
 *
 * $Id: BINReference.java,v 1.23 2008/06/10 02:52:13 cwl Exp $
 */

package com.sleepycat.je.tree;

import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;

import com.sleepycat.je.dbi.DatabaseId;

/**
 * A class that embodies a reference to a BIN that does not rely on a
 * Java reference to the actual BIN.
 */
public class BINReference {
    protected byte[] idKey;
    private long nodeId;
    private DatabaseId databaseId;
    private Set<Key> deletedKeys;  // Set of Key objects

    BINReference(long nodeId, DatabaseId databaseId, byte[] idKey) {
	this.nodeId = nodeId;
	this.databaseId = databaseId;
	this.idKey = idKey;
    }

    public long getNodeId() {
	return nodeId;
    }

    public DatabaseId getDatabaseId() {
	return databaseId;
    }

    public byte[] getKey() {
	return idKey;
    }

    public byte[] getData() {
	return null;
    }

    public void addDeletedKey(Key key) {

        if (deletedKeys == null) {
            deletedKeys = new HashSet<Key>();
        }
        deletedKeys.add(key);
    }

    public void addDeletedKeys(BINReference other) {

        if (deletedKeys == null) {
            deletedKeys = new HashSet<Key>();
        }
        if (other.deletedKeys != null) {
            deletedKeys.addAll(other.deletedKeys);
        }
    }

    public void removeDeletedKey(Key key) {

        if (deletedKeys != null) {
            deletedKeys.remove(key);
            if (deletedKeys.size() == 0) {
                deletedKeys = null;
            }
        }
    }

    public boolean hasDeletedKey(Key key) {

        return (deletedKeys != null) && deletedKeys.contains(key);
    }

    public boolean deletedKeysExist() {

        return ((deletedKeys != null) && (deletedKeys.size() > 0));
    }

    public Iterator<Key> getDeletedKeyIterator() {
        if (deletedKeys != null) {
            return deletedKeys.iterator();
        } else {
            return null;
        }
    }

    /**
     * Compare two BINReferences.
     */
    @Override
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }

        if (!(obj instanceof BINReference)) {
            return false;
        }

	return ((BINReference) obj).nodeId == nodeId;
    }

    @Override
    public int hashCode() {
	return (int) nodeId;
    }

    @Override
    public String toString() {
        return "idKey=" + Key.getNoFormatString(idKey) +
            " nodeId = " + nodeId +
            " db=" + databaseId +
            " deletedKeys=" + deletedKeys;
    }
}

