mariadb-columnstore-engine/dbcon/joblist/groupconcat.h

/* Copyright (C) 2014 InfiniDB, Inc.

   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; version 2 of
   the License.

   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. */

//  $Id: groupconcat.h 9705 2013-07-17 20:06:07Z pleblanc $


/** @file */

#ifndef GROUP_CONCAT_H
#define GROUP_CONCAT_H

#include <utility>
#include <set>
#include <vector>
#include <boost/scoped_ptr.hpp>
#include <boost/shared_array.hpp>

#include "returnedcolumn.h" // SRCP
#include "rowgroup.h"       // RowGroup
#include "rowaggregation.h" // SP_GroupConcat
#include "limitedorderby.h" // IdbOrderBy

#if defined(_MSC_VER) && defined(JOBLIST_DLLEXPORT)
#define EXPORT __declspec(dllexport)
#else
#define EXPORT
#endif

namespace joblist
{

// forward reference
struct JobInfo;
class  GroupConcator;
class  ResourceManager;


class GroupConcatInfo
{
public:
    GroupConcatInfo();
    virtual ~GroupConcatInfo();

    void prepGroupConcat(JobInfo&);
    void mapColumns(const rowgroup::RowGroup&);

    std::set<uint32_t>& columns()
    {
        return fColumns;
    }
    std::vector<rowgroup::SP_GroupConcat>& groupConcat()
    {
        return fGroupConcat;
    }

    const std::string toString() const;

protected:
    uint32_t getColumnKey(const execplan::SRCP& srcp, JobInfo& jobInfo);
    boost::shared_array<int> makeMapping(const rowgroup::RowGroup&, const rowgroup::RowGroup&);

    std::set<uint32_t>                        fColumns;
    std::vector<rowgroup::SP_GroupConcat> fGroupConcat;
};


class GroupConcatAgUM : public rowgroup::GroupConcatAg
{
public:
    EXPORT GroupConcatAgUM(rowgroup::SP_GroupConcat&);
    EXPORT ~GroupConcatAgUM();

    void initialize();
    void processRow(const rowgroup::Row&);
    EXPORT void merge(const rowgroup::Row&, int64_t);
    boost::scoped_ptr<GroupConcator>& concator()
    {
        return fConcator;
    }

    EXPORT void getResult(uint8_t*);
    EXPORT uint8_t* getResult();

protected:
    void applyMapping(const boost::shared_array<int>&, const rowgroup::Row&);

    boost::scoped_ptr<GroupConcator>      fConcator;
    boost::scoped_array<uint8_t>          fData;
    rowgroup::Row                         fRow;
    bool                                  fNoOrder;
};


// GROUP_CONCAT base
class GroupConcator
{
public:
    GroupConcator();
    virtual ~GroupConcator();

    virtual void initialize(const rowgroup::SP_GroupConcat&);
    virtual void processRow(const rowgroup::Row&) = 0;

    virtual void merge(GroupConcator*) = 0;
    virtual void getResult(uint8_t* buff, const std::string& sep) = 0;
    virtual uint8_t* getResult(const std::string& sep);

    virtual const std::string toString() const;

protected:
    virtual bool concatColIsNull(const rowgroup::Row&);
    virtual void outputRow(std::ostringstream&, const rowgroup::Row&);
    virtual int64_t lengthEstimate(const rowgroup::Row&);

    std::vector<uint32_t>                 fConcatColumns;
    std::vector<std::pair<std::string, uint32_t> >  fConstCols;
    int64_t                               fCurrentLength;
    int64_t                               fGroupConcatLen;
    int64_t                               fConstantLen;
    boost::scoped_array<uint8_t>          fOutputString;
    std::string fTimeZone;
};


// For GROUP_CONCAT withour distinct or orderby
class GroupConcatNoOrder : public GroupConcator
{
public:
    GroupConcatNoOrder();
    virtual ~GroupConcatNoOrder();

    void initialize(const rowgroup::SP_GroupConcat&);
    void processRow(const rowgroup::Row&);

    void merge(GroupConcator*);
    void getResult(uint8_t* buff, const std::string& sep);

    const std::string toString() const;

protected:
    rowgroup::RowGroup                    fRowGroup;
    rowgroup::Row                         fRow;
    rowgroup::RGData                      fData;
    std::queue<rowgroup::RGData>          fDataQueue;
    uint64_t                              fRowsPerRG;
    uint64_t                              fErrorCode;
    uint64_t                              fMemSize;
    ResourceManager*                      fRm;
    boost::shared_ptr<int64_t>			  fSessionMemLimit;
};


// ORDER BY used in GROUP_CONCAT class
// This version is for GROUP_CONCAT, the size is limited by the group_concat_max_len.
class GroupConcatOrderBy : public GroupConcator, public ordering::IdbOrderBy
{
public:
    GroupConcatOrderBy();
    virtual ~GroupConcatOrderBy();

    void initialize(const rowgroup::SP_GroupConcat&);
    void processRow(const rowgroup::Row&);
    uint64_t getKeyLength() const;

    void merge(GroupConcator*);
    void getResult(uint8_t* buff, const std::string& sep);

    const std::string toString() const;

protected:
};

}

#undef EXPORT

#endif  // GROUP_CONCAT_H