WT Matchmaker

/* not an actual program, just an idea I had */

#define QUIT_TIME 300   /* seconds after join */
#define MAX_LEAVES  /* maximum count of leaves allowed */

class user{
public:
    std::string userName;
    uint32_t userID;    /* 2^32 values for users is enough,
                   we do not expect half of the population to play this game */
    uint16_t mapID;     /* 65536 values to identify map is enough */
    uint16_t lastMapID;
    uint8_t leaveCount;     /* 256 values to keep track of leaves is enough */
    uint64_t joinTime;      /* same time as linux epoch */
    uint64_t leaveTime;
    ...             /* more variables for user */
};


/**
 * @brief check if user quits before certain time
 * @param pointer to user
 * @return true if user quits before QUIT_TIME
 */
bool quitAfterJoin(user *usr){
    /* if user leaves in first 5 minutes after join, time can be changed */
    if(abs(user->joinTime - user->leaveTime) < QUIT_TIME){
        /* set last map ID and retur flag that user quit before certain time */
        usr->lastMapID = map.ID;
        if(usr->lastMapID == usr->mapID){
            usr->leaveCount++;
            return true;
        }
    }
    return false;
}

/**
 * @brief function called after user joins in the game
 * @param pointer to user
 * @return true if join is successful
 */
bool join(user *usr){
    usr->mapID = map.ID;
    ... /* etc. */
}

/**
 * @brief overloaded function to join with preferences
 * @param mapID mapID which user does not want to join
 * @return true if joining was successful
 */
bool tryToJoin(uint16_t mapID){
    /* exclude map from list of possible maps */
    excludeMap(mapID);

    /* other operations before joining */
    ...
}

/**
 * @brief default function to join without preferences
 * @param mapID mapID which user does not want to join
 * @return true if joining was successful
 */
bool tryToJoin(){
    /* normal joining procedure */
    ...
}

/**
 * @brief user joins Q
 * @param pointer to user
 * @return true if queueing up is successful
 */
bool queueUp(user *usr){
    ...     /* some preparations */
    /* if user quits game before certain time, we can be sure he does not want to play
       in that game, therefore we will NOT match him in that game
    */
    try{
        if(usr->leaveCount > MAX_LEAVES){
            /* try to join excluding this certain map */
            tryToJoin(usr->lastMapID);
        } else {
            tryToJoin();
        }
    }
    catch{
        /* procedure that is called when Q failed */
        abortQueue();
        return false;
    }
    return true;
}