/* Copyright (C) 2017 MariaDB Corporation 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. */ #include #include #include #include "regr_syy.h" #include "bytestream.h" #include "objectreader.h" using namespace mcsv1sdk; class Add_regr_syy_ToUDAFMap { public: Add_regr_syy_ToUDAFMap() { UDAFMap::getMap()["regr_syy"] = new regr_syy(); } }; static Add_regr_syy_ToUDAFMap addToMap; // Use the simple data model struct regr_syy_data { uint64_t cnt; long double avgy; long double cy; // sum of (y squared) }; mcsv1_UDAF::ReturnCode regr_syy::init(mcsv1Context* context, ColumnDatum* colTypes) { if (context->getParameterCount() != 2) { // The error message will be prepended with // "The storage engine for the table doesn't support " context->setErrorMessage("regr_syy() with other than 2 arguments"); return mcsv1_UDAF::ERROR; } if (!(isNumeric(colTypes[0].dataType))) { // The error message will be prepended with // "The storage engine for the table doesn't support " context->setErrorMessage("regr_syy() with a non-numeric dependant (first) argument"); return mcsv1_UDAF::ERROR; } context->setUserDataSize(sizeof(regr_syy_data)); context->setResultType(execplan::CalpontSystemCatalog::DOUBLE); context->setColWidth(8); context->setScale(DECIMAL_NOT_SPECIFIED); context->setPrecision(0); context->setRunFlag(mcsv1sdk::UDAF_IGNORE_NULLS); return mcsv1_UDAF::SUCCESS; } mcsv1_UDAF::ReturnCode regr_syy::reset(mcsv1Context* context) { struct regr_syy_data* data = (struct regr_syy_data*)context->getUserData()->data; data->cnt = 0; data->avgy = 0.0; data->cy = 0.0; return mcsv1_UDAF::SUCCESS; } mcsv1_UDAF::ReturnCode regr_syy::nextValue(mcsv1Context* context, ColumnDatum* valsIn) { double valy = toDouble(valsIn[0]); struct regr_syy_data* data = (struct regr_syy_data*)context->getUserData()->data; long double avgyPrev = data->avgy; long double cyPrev = data->cy; ++data->cnt; uint64_t cnt = data->cnt; long double dy = valy - avgyPrev; avgyPrev += dy / cnt; cyPrev += dy * (valy - avgyPrev); data->avgy = avgyPrev; data->cy = cyPrev; return mcsv1_UDAF::SUCCESS; } mcsv1_UDAF::ReturnCode regr_syy::subEvaluate(mcsv1Context* context, const UserData* userDataIn) { if (!userDataIn) { return mcsv1_UDAF::SUCCESS; } struct regr_syy_data* outData = (struct regr_syy_data*)context->getUserData()->data; struct regr_syy_data* inData = (struct regr_syy_data*)userDataIn->data; uint64_t outCnt = outData->cnt; long double outAvgy = outData->avgy; long double outCy = outData->cy; uint64_t inCnt = inData->cnt; long double inAvgy = inData->avgy; long double inCy = inData->cy; uint64_t resCnt = inCnt + outCnt; if (resCnt == 0) { outData->avgy = 0; outData->cy = 0; outData->cnt = 0; } else { long double deltay = outAvgy - inAvgy; long double resAvgy = inAvgy + deltay * outCnt / resCnt; long double resCy = outCy + inCy + deltay * deltay * inCnt * outCnt / resCnt; outData->avgy = resAvgy; outData->cy = resCy; outData->cnt = resCnt; } return mcsv1_UDAF::SUCCESS; } mcsv1_UDAF::ReturnCode regr_syy::evaluate(mcsv1Context* context, static_any::any& valOut) { struct regr_syy_data* data = (struct regr_syy_data*)context->getUserData()->data; long double N = data->cnt; if (N > 0) { long double var_popy = data->cy; if (var_popy < 0) // might be -0 var_popy = 0; valOut = static_cast(var_popy); } return mcsv1_UDAF::SUCCESS; } mcsv1_UDAF::ReturnCode regr_syy::dropValue(mcsv1Context* context, ColumnDatum* valsDropped) { double valy = toDouble(valsDropped[0]); struct regr_syy_data* data = (struct regr_syy_data*)context->getUserData()->data; long double avgyPrev = data->avgy; long double cyPrev = data->cy; --data->cnt; uint64_t cnt = data->cnt; if (cnt == 0) { data->avgy = 0; data->cy = 0; } else { long double dy = valy - avgyPrev; avgyPrev -= dy / cnt; cyPrev -= dy * (valy - avgyPrev); data->avgy = avgyPrev; data->cy = cyPrev; } return mcsv1_UDAF::SUCCESS; }