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put_row.c
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/**
* \file lib/segment/put_row.c
*
* \brief Write segment row routines.
*
* This program is free software under the GNU General Public License
* (>=v2). Read the file COPYING that comes with GRASS for details.
*
* \author GRASS Development Team
*
* \date 2005-2018
*/
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <grass/gis.h>
#include <grass/glocale.h>
#include "local_proto.h"
/* buf is CELL * WRAT code */
/* int Segment_put_row (SEGMENT *SEG, CELL *buf,int row) */
/**
* \brief Write row to segment file.
*
* Transfers non-segmented matrix data, row by row, into a segment
* file. <b>seg</b> is the segment structure that was configured from a
* call to <i>Segment_init()</i>. <b>buf</b> should contain
* <em>ncols*len</em> bytes of data to be transferred to the segment
* file. <b>row</b> specifies the row from the data matrix being
* transferred.
*
* \param[in,out] SEG segment
* \param[in] buf data to write to segment
* \param[in] row
* \return 1 if successful
* \return -1 if unable to seek or write segment file
*/
int Segment_put_row(const SEGMENT *SEG, const void *buf, off_t row)
{
int size;
off_t ncols;
int scols;
int n, index;
int result;
off_t col;
if (SEG->cache) {
memcpy(SEG->cache + ((size_t)row * SEG->ncols) * SEG->len, buf,
SEG->len * SEG->ncols);
return 1;
}
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) {
SEG->address(SEG, row, col, &n, &index);
if (SEG->seek(SEG, n, index) == -1) {
int err = errno;
G_warning(_("File read/write operation failed: %s (%d)"),
strerror(err), err);
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)) {
SEG->address(SEG, row, col, &n, &index);
if (SEG->seek(SEG, n, index) == -1) {
int err = errno;
G_warning(_("File read/write operation failed: %s (%d)"),
strerror(err), err);
return -1;
}
if (write(SEG->fd, buf, size) != size) {
G_warning("Segment_put_row final write error: %s", strerror(errno));
return -1;
}
}
return 1;
}
G_warning
void G_warning(const char *msg,...)
Print a warning message to stderr.
Definition gis/error.c:203
Segment_put_row
int Segment_put_row(const SEGMENT *SEG, const void *buf, off_t row)
Write row to segment file.
Definition put_row.c:43
err
SYMBOL * err(FILE *fp, SYMBOL *s, char *msg)
Definition symbol/read.c:216