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mirror of https://github.com/mariadb-corporation/mariadb-columnstore-engine.git synced 2025-04-18 21:44:02 +03:00
2017-10-26 17:18:17 +01:00

84 lines
2.4 KiB
C++

/* Copyright (C) 2014 InfiniDB, Inc.
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; version 2 of
the License.
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., 51 Franklin Street, Fifth Floor, Boston,
MA 02110-1301, USA. */
/****************************************************************************
* $Id: func_left.cpp 3923 2013-06-19 21:43:06Z bwilkinson $
*
*
****************************************************************************/
#include <string>
using namespace std;
#include "functor_str.h"
#include "functioncolumn.h"
#include "utils_utf8.h"
using namespace execplan;
#include "rowgroup.h"
using namespace rowgroup;
#include "joblisttypes.h"
using namespace joblist;
namespace funcexp
{
CalpontSystemCatalog::ColType Func_left::operationType(FunctionParm& fp, CalpontSystemCatalog::ColType& resultType)
{
// operation type is not used by this functor
return fp[0]->data()->resultType();
}
std::string Func_left::getStrVal(rowgroup::Row& row,
FunctionParm& fp,
bool& isNull,
execplan::CalpontSystemCatalog::ColType&)
{
const string& tstr = fp[0]->data()->getStrVal(row, isNull);
if (isNull)
return "";
size_t strwclen = utf8::idb_mbstowcs(0, tstr.c_str(), 0) + 1;
wchar_t* wcbuf = (wchar_t*)alloca(strwclen * sizeof(wchar_t));
strwclen = utf8::idb_mbstowcs(wcbuf, tstr.c_str(), strwclen);
wstring str(wcbuf, strwclen);
int64_t pos = fp[1]->data()->getIntVal(row, isNull) - 1;
if (isNull)
return "";
if (pos == -1) // pos == 0
return "";
wstring out = str.substr(0, pos + 1);
size_t strmblen = utf8::idb_wcstombs(0, out.c_str(), 0) + 1;
char* outbuf = (char*)alloca(strmblen * sizeof(char));
strmblen = utf8::idb_wcstombs(outbuf, out.c_str(), strmblen);
return string(outbuf, strmblen);
// return str.substr(0, pos+1);
}
} // namespace funcexp
// vim:ts=4 sw=4: