games.stendhal.server.core.engine.db.StendhalBuddyDAO.java Source code

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Here is the source code for games.stendhal.server.core.engine.db.StendhalBuddyDAO.java

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/***************************************************************************
 *                    (C) Copyright 2003-2010 - Stendhal                   *
 ***************************************************************************
 ***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/
package games.stendhal.server.core.engine.db;

import games.stendhal.server.entity.player.Player;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import java.util.TreeSet;

import marauroa.server.db.DBTransaction;

import com.google.common.collect.HashMultimap;
import com.google.common.collect.Multimap;

/**
 * database access for the redundant buddy table used on the website
 */
public class StendhalBuddyDAO {

    /**
     * loads the relationship lists for the specified charname
     *
     * @param transaction DBTransaction
     * @param charname name of char
     * @return buddy list
     * @throws SQLException in case of an database error
     */
    public Multimap<String, String> loadRelations(DBTransaction transaction, String charname) throws SQLException {
        HashMultimap<String, String> map = HashMultimap.create();
        String query = "SELECT relationtype, buddy FROM buddy WHERE charname='[charname]'";
        Map<String, Object> params = new HashMap<String, Object>();
        params.put("charname", charname);
        ResultSet resultSet = transaction.query(query, params);
        while (resultSet.next()) {
            map.put(resultSet.getString(1), resultSet.getString(2));
        }
        return map;
    }

    /**
     * checks whether a palyer is ignored by another player
     *
     * @param transaction DBTransaction
     *
     * @param character character whose ignore list is checked
     * @param candidate candidate who might have been ignored
     * @return true, if the player is ginored, false otherwise
     * @throws SQLException SQLException
     */
    public boolean isIgnored(DBTransaction transaction, String character, String candidate) throws SQLException {
        Map<String, Object> params = new HashMap<String, Object>();
        params.put("charname", character);
        params.put("candidate", candidate);
        int count = transaction.querySingleCellInt(
                "SELECT count(*) FROM buddy WHERE charname='[charname]' AND buddy='[candidate]' AND relationtype='ignore'",
                params);
        return count > 0;
    }

    /**
     * saves the buddy list for the specified charname
     * 
     * @param transaction transaction
     * @param charname name of char
     * @param player player
     * @throws SQLException in case of an database error
     */
    public void saveRelations(DBTransaction transaction, String charname, Player player) throws SQLException {
        Multimap<String, String> oldList = loadRelations(transaction, charname);

        Set<String> buddies = player.getBuddies();
        buddies.add(charname);
        syncBuddyListToDB(transaction, charname, "buddy", oldList.get("buddy"), buddies);
        syncBuddyListToDB(transaction, charname, "ignore", oldList.get("ignore"), player.getIgnores());
    }

    /**
     * writes the current buddy list to the database, minimizing the write operations.
     *
     * @param transaction DBTransaction
     * @param charname name of character
     * @param relationtype type of the relationship
     * @param oldList  old buddy list from db
     * @param newList  current buddy list
     * @throws SQLException 
     * @throws SQLException in case of an database error
     */
    private void syncBuddyListToDB(DBTransaction transaction, String charname, String relationtype,
            Collection<String> oldList, Collection<String> newList) throws SQLException {
        Map<String, Object> params = new HashMap<String, Object>();
        params.put("charname", charname);
        params.put("relationtype", relationtype);

        // add
        Set<String> toAdd = new TreeSet<String>(newList);
        toAdd.removeAll(oldList);
        String query = "INSERT INTO buddy (charname, relationtype, buddy) VALUES ('[charname]', '[relationtype]', '[buddy]')";
        for (String buddy : toAdd) {
            params.put("buddy", buddy);
            transaction.execute(query, params);
        }

        // delete
        Set<String> toDel = new TreeSet<String>(oldList);
        toDel.removeAll(newList);
        query = "DELETE FROM buddy WHERE charname='[charname]' AND buddy='[buddy]' AND relationtype='[relationtype]'";
        for (String buddy : toDel) {
            params.put("buddy", buddy);
            transaction.execute(query, params);
        }
    }

}