mapnik/plugins/input/postgis/postgis_featureset.cpp

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

#include "postgis_featureset.hpp"
#include "resultset.hpp"
#include "cursorresultset.hpp"

// mapnik
#include <mapnik/global.hpp>
#include <mapnik/wkb.hpp>
#include <mapnik/unicode.hpp>
#include <mapnik/sql_utils.hpp>
#include <mapnik/feature_factory.hpp>
#include <mapnik/util/conversions.hpp>

// boost
#include <boost/algorithm/string.hpp>
#include <boost/spirit/include/qi.hpp>

// stl
#include <sstream>
#include <string>

using boost::trim_copy;
using mapnik::geometry_type;
using mapnik::byte;
using mapnik::geometry_utils;
using mapnik::feature_factory;
using mapnik::context_ptr;

postgis_featureset::postgis_featureset(boost::shared_ptr<IResultSet> const& rs,
                                       context_ptr const& ctx,
                                       std::string const& encoding,
                                       bool key_field)
    : rs_(rs),
      ctx_(ctx),
      tr_(new transcoder(encoding)),
      totalGeomSize_(0),
      feature_id_(1),
      key_field_(key_field)  {}

feature_ptr postgis_featureset::next()
{
    if (rs_->next())
    {
        // new feature
        feature_ptr feature;

        unsigned pos = 1;

        if (key_field_) {
            // create feature with user driven id from attribute
            int oid = rs_->getTypeOID(pos);
            const char* buf = rs_->getValue(pos);
            std::string name = rs_->getFieldName(pos);
            // validation happens of this type at init()
            int val;
            if (oid == 20)
            {
                val = int8net(buf);
            }
            else if (oid == 21)
            {
                val = int2net(buf);
            }
            else
            {
                val = int4net(buf);
            }
            feature = feature_factory::create(ctx_, val);
            // TODO - extend feature class to know
            // that its id is also an attribute to avoid
            // this duplication
            feature->put(name,val);
            ++pos;
        } else {
            // fallback to auto-incrementing id
            feature = feature_factory::create(ctx_,feature_id_);
            ++feature_id_;
        }

        // parse geometry
        int size = rs_->getFieldLength(0);
        const char *data = rs_->getValue(0);
        geometry_utils::from_wkb(feature->paths(), data, size);
        totalGeomSize_+=size;

        int num_attrs = ctx_->size() + 1;
        for ( ; pos < num_attrs; ++pos)
        {
            std::string name = rs_->getFieldName(pos);

            if (rs_->isNull(pos))
            {
                feature->put(name,mapnik::value_null());
            }
            else
            {
                const char* buf = rs_->getValue(pos);
                int oid = rs_->getTypeOID(pos);

                if (oid==16) //bool
                {
                    feature->put(name,(buf[0] != 0));
                }
                else if (oid==23) //int4
                {
                    int val = int4net(buf);
                    feature->put(name,val);
                }
                else if (oid==21) //int2
                {
                    int val = int2net(buf);
                    feature->put(name,val);
                }
                else if (oid==20) //int8/BigInt
                {
                    int val = int8net(buf);
                    feature->put(name,val);
                }
                else if (oid == 700) // float4
                {
                    float val;
                    float4net(val,buf);
                    feature->put(name,val);
                }
                else if (oid == 701) // float8
                {
                    double val;
                    float8net(val,buf);
                    feature->put(name,val);
                }
                else if (oid==25 || oid==1043) // text or varchar
                {
                    feature->put(name,tr_->transcode(buf));
                }
                else if (oid==1042)
                {
                    // bpchar
                    feature->put(name,tr_->transcode(trim_copy(std::string(buf)).c_str()));
                }
                else if (oid == 1700) // numeric
                {
                    std::string str = mapnik::sql_utils::numeric2string(buf);
                    double val;
                    if (mapnik::conversions::string2double(str,val))
                        feature->put(name,val);
                }
                else
                {
#ifdef MAPNIK_DEBUG
                    std::clog << "Postgis Plugin: uknown OID = " << oid << " FIXME " << std::endl;
#endif
                }
            }
        }
        return feature;
    }
    else
    {
        rs_->close();
        return feature_ptr();
    }
}


postgis_featureset::~postgis_featureset()
{
    rs_->close();
}