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/***************************************************************************
* Copyright (C) 2005 by Joris Guisson *
* [email protected] *
* *
* 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. *
* *
* This program 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 for more details. *
* *
* You should have received a copy of the GNU General Public License *
* along with this program; if not, write to the *
* Free Software Foundation, Inc., *
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. *
***************************************************************************/
#ifndef DHTDATABASE_H
#define DHTDATABASE_H
#include <qmap.h>
#include <qvaluelist.h>
#include <util/ptrmap.h>
#include <util/constants.h>
#include <util/array.h>
#include "key.h"
namespace dht
{
/// Each item may only exist for 30 minutes
const bt::Uint32 MAX_ITEM_AGE = 30 * 60 * 1000;
/**
* @author Joris Guisson
*
* Item in the database, will keep track of an IP and port combination.
* As well as the time it was inserted.
*/
class DBItem
{
bt::Uint8 item[6];
bt::TimeStamp time_stamp;
public:
DBItem();
DBItem(const bt::Uint8* ip_port);
DBItem(const DBItem & item);
virtual ~DBItem();
/// See if the item is expired
bool expired(bt::TimeStamp now) const;
/// Get the data of an item
const bt::Uint8* getData() const {return item;}
DBItem & operator = (const DBItem & item);
};
typedef QValueList<DBItem> DBItemList;
/**
* @author Joris Guisson
*
* Class where all the key value paires get stored.
*/
class Database
{
bt::PtrMap<dht::Key,DBItemList> items;
QMap<dht::Key,bt::TimeStamp> tokens;
public:
Database();
virtual ~Database();
/**
* Store an entry in the database
* @param key The key
* @param dbi The DBItem to store
*/
void store(const dht::Key & key,const DBItem & dbi);
/**
* Get max_entries items from the database, which have
* the same key, items are taken randomly from the list.
* If the key is not present no items will be returned, if
* there are fewer then max_entries items for the key, all
* entries will be returned
* @param key The key to search for
* @param dbl The list to store the items in
* @param max_entries The maximum number entries
*/
void sample(const dht::Key & key,DBItemList & dbl,bt::Uint32 max_entries);
/**
* Expire all items older then 30 minutes
* @param now The time it is now
* (we pass this along so we only have to calculate it once)
*/
void expire(bt::TimeStamp now);
/**
* Generate a write token, which will give peers write access to
* the DB.
* @param ip The IP of the peer
* @param port The port of the peer
* @return A Key
*/
dht::Key genToken(bt::Uint32 ip,bt::Uint16 port);
/**
* Check if a received token is OK.
* @param token The token received
* @param ip The ip of the sender
* @param port The port of the sender
* @return true if the token was given to this peer, false other wise
*/
bool checkToken(const dht::Key & token,bt::Uint32 ip,bt::Uint16 port);
/// Test wether or not the DB contains a key
bool contains(const dht::Key & key) const;
/// Insert an empty item (only if it isn't already in the DB)
void insert(const dht::Key & key);
};
}
#endif
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