segment/put_row.c

Go to the documentation of this file.

#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <grass/segment.h>
#include <grass/gis.h>


/*      buf is CELL *   WRAT code       */
/* int segment_put_row (SEGMENT *SEG, CELL *buf,int row) */


int segment_put_row(const SEGMENT * SEG, const void *buf, int row)
{
    int size;
    int ncols;
    int scols;
    int n, index, col;
    int result;

    ncols = SEG->ncols - SEG->spill;
    scols = SEG->scols;
    size = scols * SEG->len;
    /*      printf("segment_put_row ncols: %d, scols %d, size: %d, col %d, row: %d,  SEG->fd: %d\n",ncols,scols,size,col,row, SEG->fd); */

    for (col = 0; col < ncols; col += scols) {
        segment_address(SEG, row, col, &n, &index);
        if (segment_seek(SEG, n, index) < 0) {
            G_warning
                ("Failed seek in segment file for index = %d n = %d at col:row %d:%d",
                 index, n, col, row);
            return -1;
        }

        if ((result = write(SEG->fd, buf, size)) != size) {
            G_warning("segment_put_row write error %s", strerror(errno));
            /*      printf("segment_put_row result = %d. ncols: %d, scols %d, size: %d, col %d, row: %d,  SEG->fd: %d\n",result,ncols,scols,size,col,row, SEG->fd); */
            return -1;
        }

        /* The buf variable is a void pointer and thus points to anything. */
        /* Therefore, it's size is unknown and thus, it cannot be used for */
        /* pointer arithmetic (some compilers treat this as an error - SGI */
        /* MIPSPro compiler for one). Since the read command is reading in */
        /* "size" bytes, cast the buf variable to char * before incrementing */
        buf = ((const char *)buf) + size;
    }

    if ((size = SEG->spill * SEG->len)) {
        segment_address(SEG, row, col, &n, &index);
        if (segment_seek(SEG, n, index) < 0) {
            G_warning
                ("Failed seek in segment file for index = %d n = %d at col:row %d:%d",
                 index, n, col, row);
            return -1;
        }
        if (write(SEG->fd, buf, size) != size) {
            G_warning("segment_put_row final write error: %s",
                      strerror(errno));
            return -1;
        }
    }

    return 1;
}