IO.h

#ifndef _IO_SPGEMM_H
#define _IO_SPGEMM_H

#include "Triple.h"
#include "CSC.h"
#include <fstream>

#define READBUFFER (512 * 1024 * 1024)  // in MB

template <typename IT, typename NT>
int ReadBinary(string filename, CSC<IT,NT> & csc)
{
    FILE * f = fopen(filename.c_str(), "r");
    if(!f)
    {
        cerr << "Problem reading binary input file" << filename << endl;
        return -1;
    }
    IT m,n,nnz;
    fread(&m, sizeof(IT), 1, f);
    fread(&n, sizeof(IT), 1, f);
    fread(&nnz, sizeof(IT), 1, f);
    
    if (m <= 0 || n <= 0 || nnz <= 0)
    {
        cerr << "Problem with matrix size in binary input file" << filename << endl;
        return -1;
    }
    double start = omp_get_wtime( );
    cout << "Reading matrix with dimensions: "<< m << "-by-" << n <<" having "<< nnz << " nonzeros" << endl;
    
    IT * rowindices = new IT[nnz];
    IT * colindices = new IT[nnz];
    NT * vals = new NT[nnz];
    
    size_t rows = fread(rowindices, sizeof(IT), nnz, f);
    size_t cols = fread(colindices, sizeof(IT), nnz, f);
    size_t nums = fread(vals, sizeof(NT), nnz, f);
    
    if(rows != nnz || cols != nnz || nums != nnz)
    {
        cerr << "Problem with FREAD, aborting... " << endl;
        return -1;
    }
    double end = omp_get_wtime( );
    // printf("start = %.16g\nend = %.16g\ndiff = %.16g\n", start, end, end - start);
    printf("Converting matrix data from binary to COO fromat takes %.16g seconds.\n", end - start);

    fclose(f);
    
    csc = *(new CSC<IT,NT>(rowindices, colindices, vals , nnz, m, n));
    
    delete [] rowindices;
    delete [] colindices;
    delete [] vals;
    return 1;
}

template <typename IT, typename NT>
int ReadASCII(string filename, CSC<IT,NT> & csc)
{
    bool isSymmetric = false;
    double start = omp_get_wtime( );
    ifstream infile(filename.c_str());
    char line[256];
    char c = infile.get();
    while(c == '%')
    {
        infile.getline(line,256);
        if (strstr(line, "symmetric")) {
            isSymmetric = true;
            cout << "Matrix is symmetric" << endl;
        }
        c = infile.get();
    }
    infile.unget();

    infile.getline(line,256);
    IT m,n,nnz;
    if (typeid(IT) == typeid(int)) {
        sscanf(line, "%d %d %d", &m, &n, &nnz);
    }
    else if (typeid(IT) == typeid(long long int)) {
        sscanf(line, "%ld %ld %ld", &m, &n, &nnz);
    }
    else {
        sscanf(line, "%ld %ld %ld", &m, &n, &nnz);
    }
    
    if (isSymmetric) {
        nnz *= 2;
    }
    
    Triple<IT,NT> * triples = new Triple<IT,NT>[nnz];
    if (infile.is_open())
    {
        IT cnz = 0;	// current number of nonzeros
        while (! infile.eof() && cnz < nnz)
        {
            infile.getline(line,256);
            char *ch = line;
            triples[cnz].row = (IT)(atoi(ch));
            ch = strchr(ch, ' ');
            ch++;
            triples[cnz].col = (IT)(atoi(ch));
            ch = strchr(ch, ' ');
            
	    //added by khaled to avoid self loop
		
	    if (ch != NULL) {
                ch++;
                /* Read third word (value data)*/
                triples[cnz].val = (NT)(atoi(ch));
                ch = strchr(ch, ' ');
            }
            else {
                triples[cnz].val = 1.0;
            }
            // infile >> triples[cnz].row >> triples[cnz].col >> triples[cnz].val;	// row-col-value
            triples[cnz].row--;
            triples[cnz].col--;
            if (isSymmetric) {
                //printf("%d, %d\n", triples[cnz].col, triples[cnz].row);
		if (triples[cnz].col != triples[cnz].row) {
                    cnz++;
                    triples[cnz].col = triples[cnz - 1].row;
                    triples[cnz].row = triples[cnz - 1].col;
                    triples[cnz].val = triples[cnz - 1].val;
                }
		//added by khaled to avoid self-loop
		else if(triples[cnz].col == triples[cnz].row){
			nnz -= 2;
			continue;
	 	}
                else {
                    nnz--;
                }
            }
            ++cnz;
        }
	//printf("cnz = %d, nnz = %d\n", cnz, nnz);
        assert(cnz == nnz);
    }
    
    double end = omp_get_wtime( );
    // printf("start = %.16g\nend = %.16g\ndiff = %.16g\n", start, end, end - start);
    printf("Converting matrix data from ASCII to COO format: %.16g seconds\n", end - start);
    printf("Input Matrix: Rows = %d, Columns= %d, nnz = %d\n", m, n, nnz);
	
    cout << "Converting to csc ... " << endl << endl;
    csc= *(new CSC<IT,NT>(triples, nnz, m, n));
    csc.totalcols = n;
    delete [] triples;
    return 1;
}

#endif