the begginning

utils/windowfunction/wf_ranking.cpp

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+/* 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: wf_ranking.cpp 3932 2013-06-25 16:08:10Z xlou $
+
+
+//#define NDEBUG
+#include <cassert>
+#include <cmath>
+#include <sstream>
+#include <iomanip>
+using namespace std;
+
+#include <boost/shared_ptr.hpp>
+using namespace boost;
+
+#include "loggingid.h"
+#include "errorcodes.h"
+#include "idberrorinfo.h"
+using namespace logging;
+
+#include "rowgroup.h"
+using namespace rowgroup;
+
+#include "idborderby.h"
+using namespace ordering;
+
+#include "joblisttypes.h"
+#include "calpontsystemcatalog.h"
+using namespace execplan;
+
+#include "windowfunctionstep.h"
+using namespace joblist;
+
+#include "wf_ranking.h"
+
+
+namespace windowfunction
+{
+
+
+boost::shared_ptr<WindowFunctionType> WF_ranking::makeFunction(int id, const string& name, int ct)
+{
+	boost::shared_ptr<WindowFunctionType> func(new WF_ranking(id, name));
+	return func;
+}
+
+
+WindowFunctionType* WF_ranking::clone() const
+{
+	return new WF_ranking(*this);
+}
+
+
+void WF_ranking::resetData()
+{
+	fRank = 0;
+	fDups = 0;
+
+	WindowFunctionType::resetData();
+}
+
+
+void WF_ranking::operator()(int64_t b, int64_t e, int64_t c)
+{
+	// one row handling
+	if (fPartition.first == fPartition.second)
+	{
+		fRow.setData(getPointer(fRowData->at(fPartition.first)));
+		int64_t r = (fFunctionId == WF__PERCENT_RANK) ? 0 : 1;
+		if (fFunctionId == WF__RANK || fFunctionId == WF__DENSE_RANK)
+			setIntValue(fFieldIndex[0], r);
+		else
+			setDoubleValue(fFieldIndex[0], r);
+
+		return;
+	}
+
+	// more than one row, e > b
+	b = fPartition.first;
+	e = fPartition.second;
+	double n1 = e - b;    // count(*) - 1, n will not be 0.
+	for (c = b; c <= e; c++)
+	{
+		if (c % 1000 == 0 && fStep->cancelled())
+			break;
+
+		if (c != b &&
+			fPeer->operator()(getPointer(fRowData->at(c)), getPointer(fRowData->at(c-1))))
+		{
+			fDups++;
+		}
+		else
+		{
+			fRank++;
+			if (fFunctionId != WF__DENSE_RANK)
+				fRank += fDups;
+			fDups = 0;
+		}
+
+		fRow.setData(getPointer(fRowData->at(c)));
+		if (fFunctionId != WF__PERCENT_RANK)
+			setIntValue(fFieldIndex[0], fRank);
+		else
+			setDoubleValue(fFieldIndex[0], (fRank-1)/n1);
+	}
+
+	// Two-pass, need to find peers.
+	if (fFunctionId == WF__CUME_DIST)
+	{
+		int prevRank = ++fRank + fDups;  // hypothetical row at (e+1)
+		double n0 = (e - b + 1);         // count(*)
+		double cumeDist = 1;
+		fRow.setData(getPointer(fRowData->at(e)));
+		for (c = e; c >= b; c--)
+		{
+			if (c % 1000 == 0 && fStep->cancelled())
+				break;
+
+			fRow.setData(getPointer(fRowData->at(c)));
+			int currRank = getIntValue(fFieldIndex[0]);
+			if (currRank != prevRank)
+			{
+				cumeDist = ((double) (prevRank-1)) / n0;
+				prevRank = currRank;
+			}
+
+			setDoubleValue(fFieldIndex[0], cumeDist);
+		}
+	}
+}
+
+
+}   //namespace
+// vim:ts=4 sw=4:
+