insertpolicy.h

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/***********************************************************************
 Copyright (c) 2008-2009 by AboveNet, Inc., and (c) 2009 by Educational
 Technology Resources, Inc.  Others may also hold copyrights on code
 in this file.  See the CREDITS file in the top directory of the
 distribution for details.

 This file is part of MySQL++.

 MySQL++ is free software; you can redistribute it and/or modify it
 under the terms of the GNU Lesser General Public License as published
 by the Free Software Foundation; either version 2.1 of the License, or
 (at your option) any later version.

 MySQL++ 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 Lesser General Public
 License for more details.

 You should have received a copy of the GNU Lesser General Public
 License along with MySQL++; if not, write to the Free Software
 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301
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***********************************************************************/

#if !defined(MYSQLPP_INSERTPOLICY_H)
#define MYSQLPP_INSERTPOLICY_H

template <class AccessController = Transaction>
class MYSQLPP_EXPORT RowCountInsertPolicy
{
public:
        RowCountInsertPolicy(unsigned int rows) :
        cur_rows_(0),
        max_rows_(rows)
        {
        }

        ~RowCountInsertPolicy() { }

        template <class RowT>
        bool can_add(int, const RowT&)
        {
                if (++cur_rows_ > max_rows_) {
                        cur_rows_ = 0;
                        return false;
                }
                else {
                        return true;
                }
        }

        typedef AccessController access_controller;

private:
        unsigned int cur_rows_;
        unsigned const int max_rows_;
};


template <class AccessController = Transaction>
class MYSQLPP_EXPORT SizeThresholdInsertPolicy
{
public:
        SizeThresholdInsertPolicy(int size) :
        size_(size)
        {
        }

        ~SizeThresholdInsertPolicy() { }

        template <class RowT>
        bool can_add(int size, const RowT& object) const
        {
                return (size < size_);
        }

        typedef AccessController access_controller;

private:
        int size_;
};


template <class AccessController = Transaction>
class MYSQLPP_EXPORT MaxPacketInsertPolicy
{
public:
        MaxPacketInsertPolicy(Connection* con, int size) :
        conn_(con), size_(size)
        {
        }

        MaxPacketInsertPolicy(int size) :
        conn_(0), size_(size)
        {
        }

        ~MaxPacketInsertPolicy() { }

        template <class RowT>
        bool can_add(int size, const RowT& object) const
        {
                if (size < size_) {
                        // Haven't hit size threshold yet, so see if this next
                        // item pushes it over the line.
                        SQLStream s(conn_);
                        s << ",(" << object.value_list() << ")";
                        return (size_ - size) >= static_cast<int>(s.str().size());
                }
                else {
                        // Already too much in query buffer!
                        return false;
                }
        }

        typedef AccessController access_controller;

private:
        Connection* conn_;
        int size_;
};

#endif // !defined(MYSQLPP_INSERTPOLICY_H)

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