FullyDist.h

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/****************************************************************/
/* Parallel Combinatorial BLAS Library (for Graph Computations) */
/* version 1.6 -------------------------------------------------*/
/* date: 6/15/2017 ---------------------------------------------*/
/* authors: Ariful Azad, Aydin Buluc  --------------------------*/
/****************************************************************/
/*
 Copyright (c) 2010-2017, The Regents of the University of California
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
 in the Software without restriction, including without limitation the rights
 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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 furnished to do so, subject to the following conditions:
 
 The above copyright notice and this permission notice shall be included in
 all copies or substantial portions of the Software.
 
 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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 THE SOFTWARE.
 */


#ifndef _FULLY_DIST_H
#define _FULLY_DIST_H

#include <iostream>
#include <algorithm>
#include "myenableif.h"

namespace combblas {

template <class IT, class NT, class Enable=void>
class FullyDist
{};     // dummy generic template


template <class IT, class NT>
class FullyDist<IT, NT, typename combblas::disable_if< combblas::is_boolean<NT>::value, NT >::type >
{
public:
    explicit FullyDist():glen(0)
    {
        SpParHelper::Print("COMBBLAS Warning: It is dangerous to create (vector) objects without specifying the communicator, are you sure you want to create this object in MPI_COMM_WORLD?\n");
        commGrid.reset(new CommGrid(MPI_COMM_WORLD, 0, 0));
    }
    explicit FullyDist(IT globallen): glen(globallen)
    {
        SpParHelper::Print("COMBBLAS Warning: It is dangerous to create (vector) objects without specifying the communicator, are you sure you want to create this object in MPI_COMM_WORLD?\n");
        commGrid.reset(new CommGrid(MPI_COMM_WORLD, 0, 0));
    }
        /* ABAB: This clashes with FullyDist(IT globallen) signature on MPICH based systems that #define MPI_Comm to be an INT
    FullyDist( MPI_Comm world):glen(0)
        {
            commGrid.reset(new CommGrid(world, 0, 0));
        }*/
    FullyDist( std::shared_ptr<CommGrid> grid):glen(0)
    {
        commGrid = grid;
    }
    FullyDist( std::shared_ptr<CommGrid> grid, IT globallen): glen(globallen)
    {
        commGrid = grid;
    }
    FullyDist<IT,NT> & operator=(const FullyDist<IT,NT> & rhs)
    {
        glen = rhs.glen;
        commGrid = rhs.commGrid;
        return *this;
    }

    IT LengthUntil() const;
    IT RowLenUntil() const;
    IT RowLenUntil(int k) const;
    IT MyLocLength() const;
    IT MyRowLength() const;
    IT TotalLength() const { return glen; }
    int Owner(IT gind, IT & lind) const;
    int OwnerWithinRow(IT n_thisrow, IT ind_withinrow, IT & lind) const;

protected:
    std::shared_ptr<CommGrid> commGrid;
    IT glen;        // global length (actual "length" including zeros)
};


template <class IT, class NT>
int FullyDist<IT,NT, typename combblas::disable_if< combblas::is_boolean<NT>::value, NT >::type>
::Owner(IT gind, IT & lind) const
{
    // C++ implicitly upcasts both operands to 64-bit if one is 64-bit and other is 32-bit
    int procrows = commGrid->GetGridRows();
    IT n_perprocrow = glen / procrows;  // length on a typical processor row
    IT n_thisrow;       // length assigned to owner's processor row 
    int own_procrow;    // owner's processor row
    if(n_perprocrow != 0)
    {
        own_procrow = std::min(static_cast<int>(gind / n_perprocrow), procrows-1);  // owner's processor row
    }
    else    // all owned by the last processor row
    {
        own_procrow = procrows -1;
    }

    IT ind_withinrow = gind - (own_procrow * n_perprocrow);
    if(own_procrow == procrows-1)
        n_thisrow = glen - (n_perprocrow*(procrows-1));
    else
        n_thisrow = n_perprocrow;   

    int proccols = commGrid->GetGridCols();
    IT n_perproc = n_thisrow / proccols;    // length on a typical processor

    int own_proccol;
    if(n_perproc != 0)
    {
        own_proccol = std::min(static_cast<int>(ind_withinrow / n_perproc), proccols-1);
    }
    else
    {
        own_proccol = proccols-1;
    }
    lind = ind_withinrow - (own_proccol * n_perproc);

    // GetRank(int rowrank, int colrank) { return rowrank * grcols + colrank;}
    return commGrid->GetRank(own_procrow, own_proccol);
}

template <class IT, class NT>
int FullyDist<IT,NT,typename combblas::disable_if< combblas::is_boolean<NT>::value, NT >::type >
::OwnerWithinRow(IT n_thisrow, IT ind_withinrow, IT & lind) const
{
    int proccols = commGrid->GetGridCols();
    IT n_perproc = n_thisrow / proccols;    // length on a typical processor
    
    int own_proccol;
    if(n_perproc != 0)
    {
        own_proccol = std::min(static_cast<int>(ind_withinrow / n_perproc), proccols-1);
    }
    else
    {
        own_proccol = proccols-1;
    }
    lind = ind_withinrow - (own_proccol * n_perproc);

    return own_proccol;
}

template <class IT, class NT>
IT FullyDist<IT,NT,typename combblas::disable_if< combblas::is_boolean<NT>::value, NT >::type >
::LengthUntil() const
{
    int procrows = commGrid->GetGridRows();
    int my_procrow = commGrid->GetRankInProcCol();
    IT n_perprocrow = glen / procrows;  // length on a typical processor row
    IT n_thisrow;   // length assigned to this processor row    
    if(my_procrow == procrows-1)
        n_thisrow = glen - (n_perprocrow*(procrows-1));
    else
        n_thisrow = n_perprocrow;   

    int proccols = commGrid->GetGridCols();
    int my_proccol = commGrid->GetRankInProcRow();
    IT n_perproc = n_thisrow / proccols;    // length on a typical processor
    return ((n_perprocrow * my_procrow)+(n_perproc*my_proccol));
}

// Return the length until this processor, within this processor row only
template <class IT, class NT>
IT FullyDist<IT,NT,typename combblas::disable_if< combblas::is_boolean<NT>::value, NT >::type >
::RowLenUntil() const
{
    int procrows = commGrid->GetGridRows();
    int my_procrow = commGrid->GetRankInProcCol();
    IT n_perprocrow = glen / procrows;  // length on a typical processor row
    IT n_thisrow;   // length assigned to this processor row    
    if(my_procrow == procrows-1)
        n_thisrow = glen - (n_perprocrow*(procrows-1));
    else
        n_thisrow = n_perprocrow;   

    int proccols = commGrid->GetGridCols();
    int my_proccol = commGrid->GetRankInProcRow();
    IT n_perproc = n_thisrow / proccols;    // length on a typical processor
    return (n_perproc*my_proccol);
}

// Return the length until the kth processor, within this processor row only
template <class IT, class NT>
IT FullyDist<IT,NT,typename combblas::disable_if< combblas::is_boolean<NT>::value, NT >::type >
::RowLenUntil(int k) const
{
    int procrows = commGrid->GetGridRows();
    int my_procrow = commGrid->GetRankInProcCol();
    IT n_perprocrow = glen / procrows;  // length on a typical processor row
    IT n_thisrow;   // length assigned to this processor row    
    if(my_procrow == procrows-1)
        n_thisrow = glen - (n_perprocrow*(procrows-1));
    else
        n_thisrow = n_perprocrow;   

    int proccols = commGrid->GetGridCols();
    IT n_perproc = n_thisrow / proccols;    // length on a typical processor
    assert(k < proccols);
    return (n_perproc*k);
}

template <class IT, class NT>
IT FullyDist<IT,NT, typename combblas::disable_if< combblas::is_boolean<NT>::value, NT >::type>
::MyLocLength() const
{
    int procrows = commGrid->GetGridRows();
    int my_procrow = commGrid->GetRankInProcCol();
    IT n_perprocrow = glen / procrows;  // length on a typical processor row
    IT n_thisrow;   // length assigned to this processor row    
    if(my_procrow == procrows-1)
        n_thisrow = glen - (n_perprocrow*(procrows-1));
    else
        n_thisrow = n_perprocrow;   

    int proccols = commGrid->GetGridCols();
    int my_proccol = commGrid->GetRankInProcRow();
    IT n_perproc = n_thisrow / proccols;    // length on a typical processor
    if(my_proccol == proccols-1)
        return (n_thisrow - (n_perproc*(proccols-1)));
    else
        return n_perproc;   
}


template <class IT, class NT>
IT FullyDist<IT,NT,typename combblas::disable_if< combblas::is_boolean<NT>::value, NT >::type>
::MyRowLength() const
{
    int procrows = commGrid->GetGridRows();
    int my_procrow = commGrid->GetRankInProcCol();
    IT n_perprocrow = glen / procrows;  // length on a typical processor row
    IT n_thisrow;   // length assigned to this processor row    
    if(my_procrow == procrows-1)
        n_thisrow = glen - (n_perprocrow*(procrows-1));
    else
        n_thisrow = n_perprocrow;   

    return n_thisrow;
}

}

#endif