mapnik/include/mapnik/sql_utils.hpp

/*****************************************************************************
 *
 * This file is part of Mapnik (c++ mapping toolkit)
 *
 * Copyright (C) 2011 Artem Pavlenko
 *
 * This library 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.
 *
 * This library 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 this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 *****************************************************************************/

#ifndef MAPNIK_SQL_UTILS_HPP
#define MAPNIK_SQL_UTILS_HPP

// boost
#include <boost/algorithm/string.hpp>
#include <boost/scoped_array.hpp>

namespace mapnik { namespace sql_utils {

    inline std::string unquote_double(const std::string& sql)
    {
        std::string table_name = sql;
        boost::algorithm::trim_if(table_name,boost::algorithm::is_any_of("\""));
        return table_name;
    }

    inline std::string unquote(const std::string& sql)
    {
        std::string table_name = sql;
        boost::algorithm::trim_if(table_name,boost::algorithm::is_any_of("\"\'"));
        return table_name;
    }

    inline void quote_attr(std::ostringstream& s, const std::string& field)
    {
        if (boost::algorithm::icontains(field,".")) {
            std::vector<std::string> parts;
            boost::split(parts, field, boost::is_any_of("."));
            s << ",\"" << parts[0] << "\".\"" << parts[1] << "\"";
        }
        else
        {
            s << ",\"" + field + "\"";
        }
    }

    inline std::string table_from_sql(const std::string& sql)
    {
        std::string table_name = sql;
        boost::algorithm::replace_all(table_name,"\n"," ");
        boost::algorithm::ireplace_all(table_name," from "," FROM ");

        std::string::size_type idx = table_name.rfind(" FROM ");
        if (idx!=std::string::npos)
        {
            idx = table_name.find_first_not_of(" ",idx+5);
            if (idx != std::string::npos)
            {
                table_name=table_name.substr(idx);
            }
            idx = table_name.find_first_of(" )");
            if (idx != std::string::npos)
            {
                table_name = table_name.substr(0,idx);
            }
        }
        return table_name;
    }

    inline std::string numeric2string(const char* buf)
    {
        int16_t ndigits = int2net(buf);
        int16_t weight  = int2net(buf+2);
        int16_t sign    = int2net(buf+4);
        int16_t dscale  = int2net(buf+6);

        boost::scoped_array<int16_t> digits(new int16_t[ndigits]);
        for (int n=0; n < ndigits ;++n)
        {
            digits[n] = int2net(buf+8+n*2);
        }

        std::ostringstream ss;

        if (sign == 0x4000) ss << "-";

        int i = std::max(weight,int16_t(0));
        int d = 0;

        // Each numeric "digit" is actually a value between 0000 and 9999 stored in a 16 bit field.
        // For example, the number 1234567809990001 is stored as four digits: [1234] [5678] [999] [1].
        // Note that the last two digits show that the leading 0's are lost when the number is split.
        // We must be careful to re-insert these 0's when building the string.

        while ( i >= 0)
        {
            if (i <= weight && d < ndigits)
            {
                // All digits after the first must be padded to make the field 4 characters long
                if (d != 0)
                {
#ifdef _WINDOWS
                    int dig = digits[d];
                    if (dig < 10)
                    {
                        ss << "000"; // 0000 - 0009
                    }
                    else if (dig < 100)
                    {
                        ss << "00";  // 0010 - 0099
                    }
                    else
                    {
                        ss << "0";   // 0100 - 0999;
                    }
#else
                    switch(digits[d])
                    {
                    case 0 ... 9:
                        ss << "000"; // 0000 - 0009
                        break;
                    case 10 ... 99:
                        ss << "00";  // 0010 - 0099
                        break;
                    case 100 ... 999:
                        ss << "0";   // 0100 - 0999
                        break;
                    }
#endif
                }
                ss << digits[d++];
            }
            else
            {
                if (d == 0)
                    ss <<  "0";
                else
                    ss <<  "0000";
            }

            i--;
        }
        if (dscale > 0)
        {
            ss << '.';
            // dscale counts the number of decimal digits following the point, not the numeric digits
            while (dscale > 0)
            {
                int value;
                if (i <= weight && d < ndigits)
                    value = digits[d++];
                else
                    value = 0;

                // Output up to 4 decimal digits for this value
                if (dscale > 0) {
                    ss << (value / 1000);
                    value %= 1000;
                    dscale--;
                }
                if (dscale > 0) {
                    ss << (value / 100);
                    value %= 100;
                    dscale--;
                }
                if (dscale > 0) {
                    ss << (value / 10);
                    value %= 10;
                    dscale--;
                }
                if (dscale > 0) {
                    ss << value;
                    dscale--;
                }

                i--;
            }
        }
        return ss.str();
    }
    }

}

#endif // MAPNIK_SQL_UTILS_HPP