programInstance.hpp

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/************************************************************************

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 All rights reserved.

 This file is part of Project Wolframe.

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    Commercial License Agreement provided with the Software or,
    alternatively, in accordance with the terms contained
    in a written agreement between the licensee and Project Wolframe.

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    Alternatively, you can redistribute this file and/or modify it
    under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    Wolframe 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.

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#ifndef _DATABASE_VM_PROGRAM_INSTANCE_HPP_INCLUDED
#define _DATABASE_VM_PROGRAM_INSTANCE_HPP_INCLUDED
#include "database/vm/programImage.hpp"
#include "database/vm/instructionSet.hpp"
#include "database/vm/valueTupleSet.hpp"
#include "database/vm/output.hpp"
#include "database/vm/subroutineFrame.hpp"
#include "database/transactionExecStatemachine.hpp"
#include "database/databaseError.hpp"
#include "types/variant.hpp"
#include <string>
#include <vector>
#include <map>

namespace _Wolframe {
namespace db {
namespace vm {
class Program;

class ProgramInstance
        :public InstructionSet
{
public:
        struct LogTraceContext;
        typedef void (*LogTraceCallBack)( const LogTraceContext* prgcontext, unsigned int ip_);

public:
        ProgramInstance()
                :m_db_stm(0)
                ,m_ip(0)
                ,m_cond(false)
                ,m_logTraceCallBack(0)
                ,m_logTraceContext(0)
        {}
        ProgramInstance( const ProgramInstance& o)
                :m_program(o.m_program)
                ,m_db_stm(o.m_db_stm)
                ,m_ip(o.m_ip)
                ,m_cond(o.m_cond)
                ,m_stack(o.m_stack)
                ,m_output(o.m_output)
                ,m_logTraceCallBack(o.m_logTraceCallBack)
                ,m_logTraceContext(o.m_logTraceContext)
        {}

        ProgramInstance( const ProgramImage& program_, TransactionExecStatemachine* db_stm_, LogTraceCallBack logTraceCallBack_=0, const LogTraceContext* logTraceContext_=0);

        bool execute();
        const OutputR& output() const                   {return m_output;}
        const DatabaseError* lastError() const          {return &m_lastError;}
        unsigned int ip() const                         {return m_ip;}

private:
        struct ResultFlags
        {
                bool is_first;          
                bool unique;            
                bool nonempty;          

                ResultFlags( const ResultFlags& o)
                        :is_first(o.is_first),unique(o.unique),nonempty(o.nonempty){}
                ResultFlags( bool unique_=false, bool nonempty_=false)
                        :is_first(true),unique(unique_),nonempty(nonempty_){}
                void clear()
                {
                        is_first = true;
                        unique = false;
                        nonempty = false;
                }
                void init( bool unique_, bool nonempty_)
                {
                        is_first = true;
                        unique = unique_;
                        nonempty = nonempty_;
                }
                bool touched()
                {
                        bool rt = !is_first;
                        is_first = false;
                        return rt;
                }
        };

        struct StackElement
        {
                StackElement()
                        :m_return_ip(0)
                        ,m_bindidx(0)
                        ,m_hintidx(0)
                {}
                StackElement( Address return_ip_, const ValueTupleSetR& parameter_)
                        :m_return_ip(return_ip_)
                        ,m_bindidx(0)
                        ,m_hintidx(0)
                        ,m_parameter(parameter_)
                {}
                StackElement( const StackElement& o)
                        :m_return_ip(o.m_return_ip)
                        ,m_bindidx(o.m_bindidx)
                        ,m_hintidx(o.m_hintidx)
                        ,m_parameter(o.m_parameter)
                        ,m_lastResult(o.m_lastResult)
                        ,m_resultFlags(o.m_resultFlags)
                        ,m_resultMap(o.m_resultMap)
                        ,m_selectedSet(o.m_selectedSet)
                        ,m_valueSet(o.m_valueSet)
                        ,m_valueIter(o.m_valueIter)
                        ,m_valueEnd(o.m_valueEnd)
                {}

                Address m_return_ip;                                    
                std::size_t m_bindidx;                                  
                ArgumentIndex m_hintidx;                                
                ValueTupleSetR m_parameter;                             
                ValueTupleSetR m_lastResult;                            
                ResultFlags m_resultFlags;                              
                std::map<ArgumentIndex,ValueTupleSetR> m_resultMap;     
                ValueTupleSetR m_selectedSet;                           
                ValueTupleSetR m_valueSet;                              
                ValueTupleSet::const_iterator m_valueIter;              
                ValueTupleSet::const_iterator m_valueEnd;               
        };

private:
        ValueTupleSetR keptResult( ArgumentIndex idx) const;
        ValueTupleSetR tupleSet( ArgumentIndex idx) const;
        const types::Variant& constArgument( ArgumentIndex idx) const;
        const std::string& statementArgument( ArgumentIndex argidx) const;
        const std::string& tagnameArgument( ArgumentIndex argidx) const;
        types::Variant loopcntArgument() const;
        ArgumentIndex columnIndex( const ValueTupleSet* valueset, ArgumentIndex nameidx) const;
        const types::Variant& selectedArgument( ArgumentIndex idx) const;
        const types::Variant& iteratorArgument( ArgumentIndex idx) const;
        void initValueIteraror( const ValueTupleSetR& valueset);
        void initResult( const ValueTupleSetR& resultset);
        void printIteratorColumn();
        ValueTupleSetR fetchDatabaseResult( std::size_t nofColumns);
        void setDatabaseError();

private:
        ProgramImage m_program;                         
        TransactionExecStatemachine* m_db_stm;          
        Address m_ip;                                   
        SubroutineFrame m_subroutine_frame;             
        bool m_cond;                                    
        std::vector<StackElement> m_stack;              
        OutputR m_output;                               
        DatabaseError m_lastError;                      
        LogTraceCallBack m_logTraceCallBack;            
        const LogTraceContext* m_logTraceContext;       
};

}}}//namespace
#endif