mapnik/plugins/input/postgis/cursorresultset.hpp
2017-05-05 13:02:01 +02:00

147 lines
3.6 KiB
C++

/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2017 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 POSTGIS_CURSORRESULTSET_HPP
#define POSTGIS_CURSORRESULTSET_HPP
#include <mapnik/debug.hpp>
#include "connection.hpp"
#include "resultset.hpp"
class CursorResultSet : public IResultSet, private mapnik::util::noncopyable
{
public:
CursorResultSet(std::shared_ptr<Connection> const &conn, std::string cursorName, int fetch_count)
: conn_(conn),
cursorName_(cursorName),
fetch_size_(fetch_count),
is_closed_(false)
{
getNextResultSet();
}
virtual ~CursorResultSet()
{
close();
}
virtual void close()
{
if (!is_closed_)
{
rs_.reset();
std::ostringstream s;
s << "CLOSE " << cursorName_;
MAPNIK_LOG_DEBUG(postgis) << "postgis_cursor_resultset: " << s.str();
conn_->execute(s.str());
is_closed_ = true;
conn_.reset();
}
}
virtual int getNumFields() const
{
return rs_->getNumFields();
}
virtual bool next()
{
if (rs_->next()) {
return true;
} else if (rs_->size() == 0) {
close();
return false;
} else {
getNextResultSet();
return rs_->next();
}
}
virtual const char* getFieldName(int index) const
{
return rs_->getFieldName(index);
}
virtual int getFieldLength(int index) const
{
return rs_->getFieldLength(index);
}
virtual int getFieldLength(const char* name) const
{
return rs_->getFieldLength(name);
}
virtual int getTypeOID(int index) const
{
return rs_->getTypeOID(index);
}
virtual int getTypeOID(const char* name) const
{
return rs_->getTypeOID(name);
}
virtual bool isNull(int index) const
{
return rs_->isNull(index);
}
virtual const char* getValue(int index) const
{
return rs_->getValue(index);
}
virtual const char* getValue(const char* name) const
{
return rs_->getValue(name);
}
private:
void getNextResultSet()
{
std::ostringstream s;
s << "FETCH FORWARD " << fetch_size_ << " FROM " << cursorName_;
MAPNIK_LOG_DEBUG(postgis) << "postgis_cursor_resultset: " << s.str();
rs_ = conn_->executeQuery(s.str());
is_closed_ = false;
MAPNIK_LOG_DEBUG(postgis) << "postgis_cursor_resultset: FETCH result (" << cursorName_ << "): " << rs_->size() << " rows";
}
std::shared_ptr<Connection> conn_;
std::string cursorName_;
std::shared_ptr<ResultSet> rs_;
int fetch_size_;
bool is_closed_;
};
#endif // POSTGIS_CURSORRESULTSET_HPP