azerothcore-wotlk/src/common/Threading/Callback.h

/*
 * Copyright (C) 2016+     AzerothCore <www.azerothcore.org>
 * Copyright (C) 2008-2016 TrinityCore <http://www.trinitycore.org/>
 * Copyright (C) 2005-2009 MaNGOS <http://getmangos.com/>
 */

#ifndef _CALLBACK_H
#define _CALLBACK_H

#include <ace/Future.h>
#include <ace/Future_Set.h>
#include "QueryResult.h"

typedef ACE_Future<QueryResult> QueryResultFuture;
typedef ACE_Future<PreparedQueryResult> PreparedQueryResultFuture;

/*! A simple template using ACE_Future to manage callbacks from the thread and object that
    issued the request. <ParamType> is variable type of parameter that is used as parameter
    for the callback function.
*/
#define CALLBACK_STAGE_INVALID uint8(-1)

template <typename Result, typename ParamType, bool chain = false>
class QueryCallback
{
public:
    QueryCallback() : _param(), _stage(chain ? 0 : CALLBACK_STAGE_INVALID)  {}

    //! The parameter of this function should be a resultset returned from either .AsyncQuery or .AsyncPQuery
    void SetFutureResult(ACE_Future<Result> value)
    {
        _result = value;
    }

    ACE_Future<Result> GetFutureResult()
    {
        return _result;
    }

    int IsReady()
    {
        return _result.ready();
    }

    void GetResult(Result& res)
    {
        _result.get(res);
    }

    void FreeResult()
    {
        _result.cancel();
    }

    void SetParam(ParamType value)
    {
        _param = value;
    }

    ParamType GetParam()
    {
        return _param;
    }

    //! Resets the stage of the callback chain
    void ResetStage()
    {
        if (!chain)
            return;

        _stage = 0;
    }

    //! Advances the callback chain to the next stage, so upper level code can act on its results accordingly
    void NextStage()
    {
        if (!chain)
            return;

        ++_stage;
    }

    //! Returns the callback stage (or CALLBACK_STAGE_INVALID if invalid)
    uint8 GetStage()
    {
        return _stage;
    }

    //! Resets all underlying variables (param, result and stage)
    void Reset()
    {
        SetParam(nullptr);
        FreeResult();
        ResetStage();
    }

private:
    ACE_Future<Result> _result;
    ParamType _param;
    uint8 _stage;
};

template <typename Result, typename ParamType1, typename ParamType2, bool chain = false>
class QueryCallback_2
{
public:
    QueryCallback_2() : _stage(chain ? 0 : CALLBACK_STAGE_INVALID) {}

    //! The parameter of this function should be a resultset returned from either .AsyncQuery or .AsyncPQuery
    void SetFutureResult(ACE_Future<Result> value)
    {
        _result = value;
    }

    ACE_Future<Result> GetFutureResult()
    {
        return _result;
    }

    int IsReady()
    {
        return _result.ready();
    }

    void GetResult(Result& res)
    {
        _result.get(res);
    }

    void FreeResult()
    {
        _result.cancel();
    }

    void SetFirstParam(ParamType1 value)
    {
        _param_1 = value;
    }

    void SetSecondParam(ParamType2 value)
    {
        _param_2 = value;
    }

    ParamType1 GetFirstParam()
    {
        return _param_1;
    }

    ParamType2 GetSecondParam()
    {
        return _param_2;
    }

    //! Resets the stage of the callback chain
    void ResetStage()
    {
        if (!chain)
            return;

        _stage = 0;
    }

    //! Advances the callback chain to the next stage, so upper level code can act on its results accordingly
    void NextStage()
    {
        if (!chain)
            return;

        ++_stage;
    }

    //! Returns the callback stage (or CALLBACK_STAGE_INVALID if invalid)
    uint8 GetStage()
    {
        return _stage;
    }

    //! Resets all underlying variables (param, result and stage)
    void Reset()
    {
        SetFirstParam(0);
        SetSecondParam(nullptr);
        FreeResult();
        ResetStage();
    }

private:
    ACE_Future<Result> _result;
    ParamType1 _param_1;
    ParamType2 _param_2;
    uint8 _stage;
};

template <typename Result, typename ParamType1, typename ParamType2, typename ParamType3, bool chain = false>
class QueryCallback_3
{
public:
    QueryCallback_3() : _stage(chain ? 0 : CALLBACK_STAGE_INVALID) {}

    //! The parameter of this function should be a resultset returned from either .AsyncQuery or .AsyncPQuery
    void SetFutureResult(ACE_Future<Result> value)
    {
        _result = value;
    }

    ACE_Future<Result> GetFutureResult()
    {
        return _result;
    }

    int IsReady()
    {
        return _result.ready();
    }

    void GetResult(Result& res)
    {
        _result.get(res);
    }

    void FreeResult()
    {
        _result.cancel();
    }

    void SetFirstParam(ParamType1 value)
    {
        _param_1 = value;
    }

    void SetSecondParam(ParamType2 value)
    {
        _param_2 = value;
    }

    void SetThirdParam(ParamType3 value)
    {
        _param_3 = value;
    }

    ParamType1 GetFirstParam()
    {
        return _param_1;
    }

    ParamType2 GetSecondParam()
    {
        return _param_2;
    }

    ParamType3 GetThirdParam()
    {
        return _param_3;
    }

    //! Resets the stage of the callback chain
    void ResetStage()
    {
        if (!chain)
            return;

        _stage = 0;
    }

    //! Advances the callback chain to the next stage, so upper level code can act on its results accordingly
    void NextStage()
    {
        if (!chain)
            return;

        ++_stage;
    }

    //! Returns the callback stage (or CALLBACK_STAGE_INVALID if invalid)
    uint8 GetStage()
    {
        return _stage;
    }

    //! Resets all underlying variables (param, result and stage)
    void Reset()
    {
        SetFirstParam(nullptr);
        SetSecondParam(nullptr);
        SetThirdParam(nullptr);
        FreeResult();
        ResetStage();
    }

private:
    ACE_Future<Result> _result;
    ParamType1 _param_1;
    ParamType2 _param_2;
    ParamType3 _param_3;
    uint8 _stage;
};

#endif