mapnik/plugins/input/postgis/postgis_featureset.cpp
2013-05-15 15:13:19 +01:00

344 lines
9.9 KiB
C++

/*****************************************************************************
*
* 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/debug.hpp>
#include <mapnik/wkb.hpp>
#include <mapnik/unicode.hpp>
#include <mapnik/value_types.hpp>
#include <mapnik/feature_factory.hpp>
#include <mapnik/util/conversions.hpp>
#include <mapnik/util/trim.hpp>
#include <mapnik/global.hpp> // for int2net
#include <boost/scoped_array.hpp>
// boost
#include <boost/cstdint.hpp> // for boost::int16_t
// stl
#include <sstream>
#include <string>
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)
{
}
std::string numeric2string(const char* buf);
feature_ptr postgis_featureset::next()
{
while (rs_->next())
{
// new feature
unsigned pos = 1;
feature_ptr feature;
if (key_field_)
{
std::string name = rs_->getFieldName(pos);
// null feature id is not acceptable
if (rs_->isNull(pos))
{
MAPNIK_LOG_WARN(postgis) << "postgis_featureset: null value encountered for key_field: " << name;
continue;
}
// create feature with user driven id from attribute
int oid = rs_->getTypeOID(pos);
const char* buf = rs_->getValue(pos);
// validation happens of this type at initialization
mapnik::value_integer 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<mapnik::value_integer>(name,std::move(val));
++pos;
}
else
{
// fallback to auto-incrementing id
feature = feature_factory::create(ctx_, feature_id_);
++feature_id_;
}
// null geometry is not acceptable
if (rs_->isNull(0))
{
MAPNIK_LOG_WARN(postgis) << "postgis_featureset: null value encountered for geometry";
continue;
}
// parse geometry
int size = rs_->getFieldLength(0);
const char *data = rs_->getValue(0);
if (!geometry_utils::from_wkb(feature->paths(), data, size))
continue;
totalGeomSize_ += size;
unsigned num_attrs = ctx_->size() + 1;
for (; pos < num_attrs; ++pos)
{
std::string name = rs_->getFieldName(pos);
// NOTE: we intentionally do not store null here
// since it is equivalent to the attribute not existing
if (!rs_->isNull(pos))
{
const char* buf = rs_->getValue(pos);
const int oid = rs_->getTypeOID(pos);
switch (oid)
{
case 16: //bool
{
feature->put(name, (buf[0] != 0));
break;
}
case 23: //int4
{
feature->put<mapnik::value_integer>(name, int4net(buf));
break;
}
case 21: //int2
{
feature->put<mapnik::value_integer>(name, int2net(buf));
break;
}
case 20: //int8/BigInt
{
feature->put<mapnik::value_integer>(name, int8net(buf));
break;
}
case 700: //float4
{
float val;
float4net(val, buf);
feature->put(name, static_cast<double>(val));
break;
}
case 701: //float8
{
double val;
float8net(val, buf);
feature->put(name, val);
break;
}
case 25: //text
case 1043: //varchar
case 705: //literal
{
feature->put(name, tr_->transcode(buf));
break;
}
case 1042: //bpchar
{
std::string str = mapnik::util::trim_copy(buf);
feature->put(name, tr_->transcode(str.c_str()));
break;
}
case 1700: //numeric
{
double val;
std::string str = numeric2string(buf);
if (mapnik::util::string2double(str, val))
{
feature->put(name, val);
}
break;
}
default:
{
MAPNIK_LOG_WARN(postgis) << "postgis_featureset: Unknown type_oid=" << oid;
break;
}
}
}
}
return feature;
}
return feature_ptr();
}
postgis_featureset::~postgis_featureset()
{
rs_->close();
}
std::string numeric2string(const char* buf)
{
boost::int16_t ndigits = int2net(buf);
boost::int16_t weight = int2net(buf+2);
boost::int16_t sign = int2net(buf+4);
boost::int16_t dscale = int2net(buf+6);
boost::scoped_array<boost::int16_t> digits(new boost::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,boost::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();
}