mmio.c

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/*************************************************************************
 * Copyright (c) 2011 AT&T Intellectual Property 
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors: Details at https://graphviz.org
 *************************************************************************/
/* 
*   Matrix Market I/O library for ANSI C
*
*   See http://math.nist.gov/MatrixMarket for details.
*
*
*/
 
#include "config.h"
 
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
#include <sparse/SparseMatrix.h>
#include <util/prisize_t.h>
#include <util/startswith.h>
#include <util/strcasecmp.h>
 
#include "mmio.h"
 
int mm_read_banner(FILE *f, matrix_shape_t *shape) {
    char line[MM_MAX_LINE_LENGTH];
    char banner[MM_MAX_TOKEN_LENGTH] = {0};
    char mtx[MM_MAX_TOKEN_LENGTH] = {0};
    char crd[MM_MAX_TOKEN_LENGTH] = {0};
    char data_type[MM_MAX_TOKEN_LENGTH] = {0};
    char storage_scheme[MM_MAX_TOKEN_LENGTH] = {0};
 
    if (fgets(line, MM_MAX_LINE_LENGTH, f) == NULL)
        return MM_PREMATURE_EOF;
 
    // note: 63 == MM_MAX_TOKEN_LENGTH - 1
    if (sscanf(line, "%63s %63s %63s %63s %63s", banner, mtx, crd, data_type,
               storage_scheme) != 5)
        return MM_PREMATURE_EOF;
 
    /* check for banner */
    if (!startswith(banner, MatrixMarketBanner))
        return MM_NO_HEADER;
 
    // first field should be “matrix”
    if (strcasecmp(mtx, MM_MTX_STR) != 0)
        return MM_UNSUPPORTED_TYPE;
 
    // second field describes whether this is a sparse matrix (in coordinate
    // storage) or a dense array
 
    if (strcasecmp(crd, MM_SPARSE_STR) != 0)
        return MM_UNSUPPORTED_TYPE;
 
    /* third field */
 
    if (strcasecmp(data_type, MM_REAL_STR) != 0)
        return MM_UNSUPPORTED_TYPE;
 
 
    /* fourth field */
 
    if (strcasecmp(storage_scheme, MM_GENERAL_STR) == 0)
        *shape = MS_GENERAL;
    else if (strcasecmp(storage_scheme, MM_SYMM_STR) == 0)
        *shape = MS_SYMMETRIC;
    else if (strcasecmp(storage_scheme, MM_HERM_STR) == 0)
        *shape = MS_HERMITIAN;
    else if (strcasecmp(storage_scheme, MM_SKEW_STR) == 0)
        *shape = MS_SKEW;
    else
        return MM_UNSUPPORTED_TYPE;
 
 
    return 0;
}
 
int mm_read_mtx_crd_size(FILE * f, int *M, int *N, size_t *nz) {
    char line[MM_MAX_LINE_LENGTH];
    int num_items_read;
 
    /* set return null parameter values, in case we exit with errors */
    *M = *N = 0;
    *nz = 0;
 
    /* now continue scanning until you reach the end-of-comments */
    do {
        if (fgets(line, MM_MAX_LINE_LENGTH, f) == NULL)
            return MM_PREMATURE_EOF;
    } while (line[0] == '%');
 
    /* line[] is either blank or has M,N, nz */
    if (sscanf(line, "%d %d %" PRISIZE_T, M, N, nz) == 3)
        return 0;
 
    else
        do {
            num_items_read = fscanf(f, "%d %d %" PRISIZE_T, M, N, nz);
            if (num_items_read == EOF)
                return MM_PREMATURE_EOF;
        }
        while (num_items_read != 3);
 
    return 0;
}