groupComp.h

#ifndef BZS_DB_PROTOCOL_TDAP_CLIENT_GROUPCOMP_H
#define BZS_DB_PROTOCOL_TDAP_CLIENT_GROUPCOMP_H
/*=================================================================
   Copyright (C) 2014-2016 BizStation Corp All rights reserved.

   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; either version 2
   of the License, or (at your option) any later version.

   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., 59 Temple Place - Suite 330, Boston, MA
   02111-1307, USA.
=================================================================*/

namespace bzs
{
namespace db
{
namespace protocol
{
namespace tdap
{
namespace client
{

/** @cond INTERNAL */

template <class Container, class FUNC>
int binary_search(int key, const Container& a, int left, int right, FUNC func,
                  bool& find)
{
    find = false;
    if (right == 0)
        return 0; // no size

    int mid, tmp, end = right;
    while (left <= right)
    {
        mid = (left + right) / 2;
        if (mid >= end)
            return end;
        if ((tmp = func(a[mid], key)) == 0)
        {
            find = true;
            return mid;
        }
        else if (tmp < 0)
            left = mid + 1; // keyValue is more large
        else
            right = mid - 1; // keyValue is more small
    }
    return left;
}

inline int compByKey(const fieldsBase& l, const fieldsBase& r, const int& s)
{
    assert((s < (int)l.size()) && (s < (int)r.size()));
    return l.getFieldNoCheck(s).comp(r.getFieldNoCheck(s), CMPLOGICAL_VAR_COMP_ALL);
}

template <class Container> class grouping_comp
{
    typedef std::vector<typename Container::key_type> key_vec;
    const key_vec& m_keys;
    Container& m_mdls;

public:
    grouping_comp(Container& mdls,
                  const std::vector<typename Container::key_type>& keys)
        : m_keys(keys), m_mdls(mdls)
    {
    }

    int operator()(int lv, int rv) const
    {
        const typename Container::row_pure_type& lm = m_mdls[lv];
        const typename Container::row_pure_type& rm = m_mdls[rv];
        for (int i = 0; i < (int)m_keys.size(); ++i)
        {
            typename Container::key_type s = m_keys[i];
            int ret = (s == -1) ? 0 : compByKey(lm, rm, s);
            if (ret)
                return ret;
        }
        return 0;
    }

    bool isEqual(const typename Container::row_type& lm,
                 const typename Container::row_type& rm)
    {
        for (int i = 0; i < m_keys.size(); ++i)
        {
            typename Container::key_type s = m_keys[i];
            int ret = (s == -1) ? 0 : compByKey(*lm, *rm, s);
            if (ret)
                return false;
        }
        return true;
    }
};

/** @endcond */

} // namespace client
} // namespace tdap
} // namespace protocol
} // namespace db
} // namespace bzs

#endif // BZS_DB_PROTOCOL_TDAP_CLIENT_GROUPCOMP_H