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/**
* \file debug.c
*
* \brief Segment debug routines.
*
* This file has debug versions of <i>segment_get()</i> and
* <i>segment_put()</i> which check the row,col and print error messages
* to <em>stderr</em> upon violations.
*
* <b>Build Note:</b> Load the debug.o file before the SEGMENTLIB and
* the debug versions will supercede the original.
*
* This program is free software under the GNU General Public License
* (>=v2). Read the file COPYING that comes with GRASS for details.
*
* \author GRASS GIS Development Team
*
* \date 2005-2006
*/
#include <stdio.h>
#include <string.h>
#include <grass/segment.h>
static int check(const SEGMENT *, int, int, char *);
/**
* \fn int segment_get (SEGMENT *SEG, void *buf, int row, int col)
*
* \brief Get value from segment file.
*
* Provides random read access to the segmented data. It gets
* <i>len</i> bytes of data into <b>value</b> from the segment file
* <b>seg</b> for the corresponding <b>row</b> and <b>col</b> in the
* original data matrix.
*
* \param[in] seg
* \param[in,out] buf
* \param[in] row
* \param[in] col
* \return 1 on success
* \return -1 if unable to seek or read segment file
*/
int segment_get(SEGMENT * SEG, void *buf, int row, int col)
{
int index, n;
if (!check(SEG, row, col, "segment_get"))
return -1;
segment_address(SEG, row, col, &n, &index);
if ((i = segment_pagein(SEG, n)) < 0)
return -1;
memcpy(buf, &SEG->scb[i].buf[index], SEG->len);
return 1;
}
/**
* \fn int segment_put (SEGMENT *SEG, void *buf, int row, int col)
*
* \brief Put value to segment file.
*
* Provides random write access to the segmented data. It
* copies <i>len</i> bytes of data from <b>value</b> into the segment
* structure <b>seg</b> for the corresponding <b>row</b> and <b>col</b> in
* the original data matrix.
*
* The data is not written to disk immediately. It is stored in a memory segment
* until the segment routines decide to page the segment to disk.
*
* \param[in] seg
* \param[in,out] buf
* \param[in] row
* \param[in] col
* \return 1 on success
* \return -1 if unable to seek or write segment file
*/
int segment_put(SEGMENT * SEG, const void *buf, int row, int col)
{
int index, n;
if (!check(SEG, row, col, "segment_put"))
return -1;
segment_address(SEG, row, col, &n, &index);
if ((i = segment_pagein(SEG, n)) < 0)
return -1;
SEG->scb[i].dirty = 1;
memcpy(&SEG->scb[i].buf[index], buf, SEG->len);
return 1;
}
static int check(const SEGMENT * SEG, int row, int col, char *me)
{
int r = row >= 0 && row < SEG->nrows;
int c = col >= 0 && col < SEG->ncols;
if (r && c)
return 1;
fprintf(stderr, "%s(SEG=%lx,fd=%d,row=%d,col=%d) ",
me, (unsigned long int)SEG, SEG->fd, row, col);
if (!r) {
fprintf(stderr, "bad row ");
if (row >= SEG->nrows)
fprintf(stderr, "(max %d) ", SEG->nrows - 1);
}
if (!c) {
fprintf(stderr, "bad col ");
if (col >= SEG->ncols)
fprintf(stderr, "(max %d) ", SEG->ncols - 1);
}
fprintf(stderr, "\n");
return 0;
}
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