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https://github.com/mariadb-corporation/mariadb-columnstore-engine.git
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76 lines
2.6 KiB
C++
76 lines
2.6 KiB
C++
/* Copyright (C) 2014 InfiniDB, Inc.
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This program is free software; you can redistribute it and/or
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modify it under the terms of the GNU General Public License
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as published by the Free Software Foundation; version 2 of
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the License.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
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MA 02110-1301, USA. */
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/****************************************************************************
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* $Id: func_right.cpp 3923 2013-06-19 21:43:06Z bwilkinson $
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*
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*
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****************************************************************************/
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#include <string>
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using namespace std;
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#include "functor_str.h"
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#include "functioncolumn.h"
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using namespace execplan;
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#include "rowgroup.h"
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using namespace rowgroup;
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#include "joblisttypes.h"
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using namespace joblist;
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namespace funcexp
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{
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CalpontSystemCatalog::ColType Func_right::operationType(FunctionParm& fp,
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CalpontSystemCatalog::ColType& resultType)
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{
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// operation type is not used by this functor
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return fp[0]->data()->resultType();
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}
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std::string Func_right::getStrVal(rowgroup::Row& row, FunctionParm& fp, bool& isNull,
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execplan::CalpontSystemCatalog::ColType& type)
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{
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CHARSET_INFO* cs = type.getCharset();
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// The original string
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const auto& src = fp[0]->data()->getStrVal(row, isNull);
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if (isNull || src.length() < 1)
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return "";
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// binLen represents the number of bytes in src
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size_t binLen = src.length();
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const char* pos = src.str();
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const char* end = pos + binLen;
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// Negative trim length values are legal, but they don't make any real sense
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int64_t trimLength = fp[1]->data()->getUintVal(row, isNull);
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if (isNull || trimLength <= 0)
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return "";
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size_t trimLengthPositive = static_cast<size_t>(trimLength); // now we are sure it is positive
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size_t start = cs->numchars(pos, end); // Here, start is number of characters in src
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if (start <= trimLengthPositive)
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return src.safeString("");
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start = cs->charpos(pos, end,
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start - trimLengthPositive); // Here, start becomes number of bytes into src to start copying
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std::string ret(pos + start, binLen - start);
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return ret;
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}
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} // namespace funcexp
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