GRASS GIS 8 Programmer's Manual
8.2.0(2022)-exported
segment/put.c
Go to the documentation of this file.
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/**
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* \file lib/segment/put.c
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*
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* \brief Segment write routines.
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*
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* This program is free software under the GNU General Public License
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* (>=v2). Read the file COPYING that comes with GRASS for details.
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*
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* \author GRASS GIS Development Team
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*
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* \date 2005-2018
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*/
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#include <string.h>
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#include <grass/gis.h>
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#include "local_proto.h"
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/*bugfix: buf: char* vs int* -> wrong pointer arithmetics!!!. Pierre de Mouveaux - 09 april 2000 */
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/* int Segment_put (SEGMENT *SEG,int *buf,int row,int col) */
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/**
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* \fn int Segment_put (SEGMENT *SEG, void *buf, int row, int col)
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*
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* \brief Write value to segment file.
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*
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* Provides random write access to the segmented data. It
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* copies <i>len</i> bytes of data from <b>buf</b> into the segment
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* structure <b>seg</b> for the corresponding <b>row</b> and <b>col</b> in
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* the original data matrix.
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*
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* The data is not written to disk immediately. It is stored in a memory segment
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* until the segment routines decide to page the segment to disk.
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*
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* \param[in,out] seg segment
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* \param[in] buf value to write to segment
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* \param[in] row
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* \param[in] col
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* \return 1 if successful
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* \return -1 if unable to seek or write segment file
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*/
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int
Segment_put
(SEGMENT * SEG,
const
void
*buf, off_t row, off_t col)
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{
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int
index, n, i;
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if
(SEG->cache) {
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memcpy(SEG->cache + ((
size_t
)row * SEG->ncols + col) * SEG->len, buf, SEG->len);
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return
1;
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}
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SEG->address(SEG, row, col, &n, &index);
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if
((i =
seg_pagein
(SEG, n)) < 0) {
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G_warning
(
"segment lib: put: pagein failed"
);
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return
-1;
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}
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SEG->scb[i].dirty = 1;
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memcpy(&SEG->scb[i].buf[index], buf, SEG->len);
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return
1;
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}
G_warning
void G_warning(const char *msg,...)
Print a warning message to stderr.
Definition:
gis/error.c:204
seg_pagein
int seg_pagein(SEGMENT *SEG, int n)
Internal use only.
Definition:
pagein.c:37
Segment_put
int Segment_put(SEGMENT *SEG, const void *buf, off_t row, off_t col)
Definition:
segment/put.c:45
segment
put.c
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