GRASS GIS 8 Programmer's Manual
8.2.2dev(2023)-3d2c704037
rowio/setup.c
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/*!
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\file rowio/setup.c
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\brief RowIO library - Setup
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(C) 2001-2009 by the GRASS Development Team
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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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\author Original author CERL
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <
grass/gis.h
>
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#include <
grass/glocale.h
>
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#include <
grass/rowio.h
>
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/*!
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* \brief Configure rowio structure
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*
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* Rowio_setup() initializes the ROWIO structure <i>r</i> and
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* allocates the required memory buffers. The file descriptor
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* <i>fd</i> must be open for reading. The number of rows to be held
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* in memory is <i>nrows</i>. The length in bytes of each row is
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* <i>len</i>. The routine which will be called to read data from the
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* file is getrow() and must be provided by the programmer. If the
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* application requires that the rows be written back into the file if
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* changed, the file descriptor <i>fd</i> must be open for write as
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* well, and the programmer must provide a putrow() routine to write
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* the data into the file. If no writing of the file is to occur,
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* specify NULL for putrow().
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*
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* \param R pointer to ROWIO structure
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* \param fd file descriptor
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* \param nrows number of rows
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* \param getrow get row function
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*
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* \return 1 on success
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* \return -1 no memory
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*/
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int
Rowio_setup
(
ROWIO
* R,
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int
fd,
int
nrows,
int
len,
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int
(*getrow) (
int
,
void
*,
int
,
int
),
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int
(*putrow) (
int
,
const
void
*,
int
,
int
))
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{
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int
i;
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R->
getrow
= getrow;
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R->
putrow
= putrow;
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R->
nrows
= nrows;
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R->
len
= len;
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R->
cur
= -1;
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R->
buf
=
NULL
;
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R->
fd
= fd;
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R->
rcb
= (
struct
ROWIO_RCB *)
G_malloc
(nrows *
sizeof
(
struct
ROWIO_RCB));
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if
(R->
rcb
==
NULL
) {
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G_warning
(
_
(
"Out of memory"
));
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return
-1;
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}
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for
(i = 0; i < nrows; i++) {
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R->
rcb
[i].
buf
=
G_malloc
(len);
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if
(R->
rcb
[i].
buf
==
NULL
) {
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G_warning
(
_
(
"Out of memory"
));
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return
-1;
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}
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R->
rcb
[i].
row
= -1;
/* mark not used */
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}
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return
1;
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}
glocale.h
G_malloc
#define G_malloc(n)
Definition:
defs/gis.h:112
ROWIO::ROWIO_RCB::buf
void * buf
Definition:
rowio.h:16
ROWIO::ROWIO_RCB::row
int row
Definition:
rowio.h:18
ROWIO::cur
int cur
Definition:
rowio.h:9
NULL
#define NULL
Definition:
ccmath.h:32
gis.h
ROWIO::putrow
int(* putrow)(int, const void *, int, int)
Definition:
rowio.h:12
ROWIO::getrow
int(* getrow)(int, void *, int, int)
Definition:
rowio.h:11
ROWIO::len
int len
Definition:
rowio.h:8
ROWIO::rcb
struct ROWIO::ROWIO_RCB * rcb
Rowio_setup
int Rowio_setup(ROWIO *R, int fd, int nrows, int len, int(*getrow)(int, void *, int, int), int(*putrow)(int, const void *, int, int))
Configure rowio structure.
Definition:
rowio/setup.c:44
ROWIO::buf
void * buf
Definition:
rowio.h:10
ROWIO
Definition:
rowio.h:4
ROWIO::fd
int fd
Definition:
rowio.h:6
G_warning
void G_warning(const char *,...) __attribute__((format(printf
ROWIO::nrows
int nrows
Definition:
rowio.h:7
_
#define _(str)
Definition:
glocale.h:10
rowio.h
lib
rowio
setup.c
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