summaryrefslogtreecommitdiff
path: root/src/include/taler_db_lib.h
blob: 41b46264e1e1c55e906447b24582ad1e205042f7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
/*
  This file is part of TALER
  (C) 2014 Christian Grothoff (and other contributing authors)

  TALER is free software; you can redistribute it and/or modify it under the
  terms of the GNU General Public License as published by the Free Software
  Foundation; either version 3, or (at your option) any later version.

  TALER is distributed in the hope that it will be useful, but WITHOUT ANY
  WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  A PARTICULAR PURPOSE.  See the GNU General Public License for more details.

  You should have received a copy of the GNU General Public License along with
  TALER; see the file COPYING.  If not, If not, see <http://www.gnu.org/licenses/>
*/


/**
 * @file include/taler_db_lib.h
 * @brief helper functions for DB interactions
 * @author Sree Harsha Totakura <sreeharsha@totakura.in>
 * @author Florian Dold
 */

#ifndef TALER_DB_LIB_H_
#define TALER_DB_LIB_H_

#include <libpq-fe.h>
#include "taler_util.h"

#define TALER_DB_QUERY_PARAM_END { NULL, 0, 0 }
#define TALER_DB_QUERY_PARAM_PTR(x) { (x), sizeof (*(x)), 1 }
#define TALER_DB_QUERY_PARAM_PTR_SIZED(x, s) { (x), (s), 1 }


#define TALER_DB_RESULT_SPEC_END { NULL, 0, NULL }
#define TALER_DB_RESULT_SPEC(name, dst) { (void *) (dst), sizeof (*(dst)), (name) }
#define TALER_DB_RESULT_SPEC_SIZED(name, dst, s) { (void *) (dst), (s), (name) }


/**
 * Description of a DB query parameter.
 */
struct TALER_DB_QueryParam
{
  /**
   * Data or NULL
   */
  const void *data;
  /**
   * Size of 'data'
   */
  size_t size;
  /**
   * Non-null if this is not the last parameter.
   * This allows for null as sentinal value.
   */
  int more;
};


/**
 * Description of a DB result cell.
 */
struct TALER_DB_ResultSpec
{
  /**
   * Destination for the data.
   */
  void *dst;

  /**
   * Allowed size for the data.
   */
  size_t dst_size;

  /**
   * Field name of the desired result.
   */
  char *fname;
};


/**
 * Execute a prepared statement.
 */
PGresult *
TALER_DB_exec_prepared (PGconn *db_conn,
                        const char *name,
                        const struct TALER_DB_QueryParam *params);


/**
 * Extract results from a query result according to the given specification.
 * If colums are NULL, the destination is not modified, and GNUNET_NO
 * is returned.
 *
 * @return
 *   GNUNET_YES if all results could be extracted
 *   GNUNET_NO if at least one result was NULL
 *   GNUNET_SYSERR if a result was invalid (non-existing field)
 */
int
TALER_DB_extract_result (PGresult *result, struct TALER_DB_ResultSpec *rs, int row);


int
TALER_DB_field_isnull (PGresult *result,
                       int row,
                       const char *fname);


int
TALER_DB_extract_amount_nbo (PGresult *result,
                             int row,
                             const char *val_name,
                             const char *frac_name,
                             const char *curr_name,
                             struct TALER_AmountNBO *r_amount_nbo);


int
TALER_DB_extract_amount (PGresult *result,
                         int row,
                         const char *val_name,
                         const char *frac_name,
                         const char *curr_name,
                         struct TALER_Amount *r_amount);

#endif  /* TALER_DB_LIB_H_ */

/* end of include/taler_db_lib.h */