lookup_table.h

/*
 * Copyright 2016 Ophidian
Licensed to the Apache Software Foundation (ASF) under one
or more contributor license agreements.  See the NOTICE file
distributed with this work for additional information
regarding copyright ownership.  The ASF licenses this file
to you under the Apache License, Version 2.0 (the
"License"); you may not use this file except in compliance
with the License.  You may obtain a copy of the License at

  http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing,
software distributed under the License is distributed on an
"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
KIND, either express or implied.  See the License for the
specific language governing permissions and limitations
under the License.
 */

#ifndef SRC_TIMING_LOOKUP_TABLE_H_
#define SRC_TIMING_LOOKUP_TABLE_H_

#include <boost/units/io.hpp>
#include <boost/units/systems/si.hpp>
#include <boost/units/systems/si/prefixes.hpp>
#include <iostream>

namespace ophidian {
namespace timing {

template<class RowType, class ColumnType, class ValueType>
class lookup_table {
    std::vector<RowType> m_row_values;
    std::vector<ColumnType> m_column_values;
    std::vector<std::vector<ValueType> > m_values;
public:

    bool operator==(const lookup_table<RowType, ColumnType, ValueType> & lut) const
    {
        return (m_row_values == lut.m_row_values)&&(m_column_values==lut.m_column_values)&&(m_values==lut.m_values);
    }

    lookup_table(std::size_t rows=0, std::size_t columns=0) :
            m_row_values(rows), m_column_values(columns), m_values(rows,
                    std::vector<ValueType>(columns)) {

    }
    virtual ~lookup_table() {

    }

    std::size_t row_count() const {
        return m_row_values.size();
    }
    void row_value(std::size_t column, RowType value) {
        m_row_values[column] = value;
    }

    RowType row_value(std::size_t column) const {
        return m_row_values[column];
    }

    std::size_t column_count() const {
        return m_column_values.size();
    }

    void column_value(std::size_t row, ColumnType value) {
        m_column_values[row] = value;
    }

    ColumnType column_value(std::size_t row) const {
        return m_column_values[row];
    }

    ValueType at(std::size_t row, std::size_t column) const {
        return m_values.at(row).at(column);
    }

    void at(std::size_t row, std::size_t column, ValueType value) {
        if(row >= m_values.size() || column >= m_values.front().size())
            std::cout << "ERROO!!!" << std::endl;
        m_values.at(row).at(column) = value;
    }

    ValueType compute(RowType rv, ColumnType cv) const {

        if (m_values.size() == 1)
            if (m_values.front().size() == 1)
                return m_values.front().front();

        double wTransition, wLoad;
        RowType y1, y2;

        ColumnType x1, x2;
        ValueType t[2][2];
        std::size_t row1, row2, column1, column2;
        wTransition = 0.0f;
        wLoad = 0.0f;

        row1 = m_row_values.size() - 2;
        row2 = m_row_values.size() - 1;

        y1 = m_row_values[row1];
        y2 = m_row_values[row2];

        // loads -- rows
        for (size_t i = 0; i < m_row_values.size() - 1; i++) {
            if (rv >= m_row_values[i] && rv <= m_row_values[i + 1]) {
                row1 = i;
                row2 = i + 1;
                y1 = m_row_values[row1];
                y2 = m_row_values[row2];
            }
        }

        // transitions -- columns
        if (cv < m_column_values[0]) {
            column1 = 0;
            column2 = 1;
            x1 = m_column_values[column1];
            x2 = m_column_values[column2];
        } else if (cv
                > m_column_values[m_column_values.size() - 1]) {
            column1 = m_column_values.size() - 2;
            column2 = m_column_values.size() - 1;
            x1 = m_column_values[column1];
            x2 = m_column_values[column2];
        } else {
            for (size_t i = 0; i < m_column_values.size() - 1; i++) {
                if (cv >= m_column_values[i]
                        && cv <= m_column_values[i + 1]) {
                    column1 = i;
                    column2 = i + 1;
                    x1 = m_column_values[column1];
                    x2 = m_column_values[column2];
                }
            }
        }

        //equation for interpolation (Ref - ISPD Contest: http://www.ispd.cc/contests/12/ISPD_2012_Contest_Details.pdf), slide 17
        wTransition = (cv - x1) / (x2 - x1);
        wLoad = (rv - y1) / (y2 - y1);

        t[0][0] = m_values[row1][column1];
        t[0][1] = m_values[row1][column2];
        t[1][0] = m_values[row2][column1];
        t[1][1] = m_values[row2][column2];

        return boost::units::quantity<boost::units::si::time>(((1 - wTransition) * (1 - wLoad) * t[0][0])
                + (wTransition * (1 - wLoad) * t[0][1])
                + ((1 - wTransition) * wLoad * t[1][0])
                + (wTransition * wLoad * t[1][1]));

    }

};

} /* namespace timing */
} /* namespace openeda */

#endif /* SRC_TIMING_LOOKUP_TABLE_H_ */