Line data Source code
1 : /*
2 : This file is part of TALER
3 : Copyright (C) 2025 Taler Systems SA
4 :
5 : TALER is free software; you can redistribute it and/or modify it under the
6 : terms of the GNU General Public License as published by the Free Software
7 : Foundation; either version 3, or (at your option) any later version.
8 :
9 : TALER is distributed in the hope that it will be useful, but WITHOUT ANY
10 : WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
11 : A PARTICULAR PURPOSE. See the GNU General Public License for more details.
12 :
13 : You should have received a copy of the GNU General Public License along with
14 : TALER; see the file COPYING. If not, see <http://www.gnu.org/licenses/>
15 : */
16 : /**
17 : * @file src/backenddb/iterate_product_groups.c
18 : * @brief Implementation of the iterate_product_groups function for Postgres
19 : * @author Christian Grothoff
20 : */
21 : #include "platform.h"
22 : #include <taler/taler_pq_lib.h>
23 : #include "merchant-database/iterate_product_groups.h"
24 : #include "helper.h"
25 :
26 :
27 : /**
28 : * Hard upper bound on the number of records returned by a single
29 : * call, regardless of the limit requested by the client.
30 : */
31 : #define MAX_RECORDS 50000
32 :
33 :
34 : /**
35 : * Context used for TALER_MERCHANTDB_iterate_product_groups().
36 : */
37 : struct LookupProductGroupsContext
38 : {
39 : /**
40 : * Function to call with the results.
41 : */
42 : TALER_MERCHANTDB_ProductGroupsCallback cb;
43 :
44 : /**
45 : * Closure for @a cb.
46 : */
47 : void *cb_cls;
48 :
49 : /**
50 : * Did database result extraction fail?
51 : */
52 : bool extract_failed;
53 : };
54 :
55 :
56 : /**
57 : * Function to be called with the results of a SELECT statement
58 : * that has returned @a num_results results about product groups.
59 : *
60 : * @param[in,out] cls of type `struct LookupProductGroupsContext *`
61 : * @param result the postgres result
62 : * @param num_results the number of results in @a result
63 : */
64 : static void
65 0 : lookup_product_groups_cb (void *cls,
66 : PGresult *result,
67 : unsigned int num_results)
68 : {
69 0 : struct LookupProductGroupsContext *plc = cls;
70 :
71 0 : for (unsigned int i = 0; i < num_results; i++)
72 : {
73 : uint64_t product_group_serial;
74 : char *product_group_name;
75 : char *product_group_description;
76 0 : struct GNUNET_PQ_ResultSpec rs[] = {
77 0 : GNUNET_PQ_result_spec_uint64 ("product_group_serial",
78 : &product_group_serial),
79 0 : GNUNET_PQ_result_spec_string ("product_group_name",
80 : &product_group_name),
81 0 : GNUNET_PQ_result_spec_string ("product_group_description",
82 : &product_group_description),
83 : GNUNET_PQ_result_spec_end
84 : };
85 :
86 0 : if (GNUNET_OK !=
87 0 : GNUNET_PQ_extract_result (result,
88 : rs,
89 : i))
90 : {
91 0 : GNUNET_break (0);
92 0 : plc->extract_failed = true;
93 0 : return;
94 : }
95 0 : plc->cb (plc->cb_cls,
96 : product_group_serial,
97 : product_group_name,
98 : product_group_description);
99 0 : GNUNET_PQ_cleanup_result (rs);
100 : }
101 : }
102 :
103 :
104 : enum GNUNET_DB_QueryStatus
105 0 : TALER_MERCHANTDB_iterate_product_groups (
106 : struct TALER_MERCHANTDB_PostgresContext *pg,
107 : const char *instance_id,
108 : int64_t limit,
109 : uint64_t offset,
110 : TALER_MERCHANTDB_ProductGroupsCallback cb,
111 : void *cb_cls)
112 : {
113 0 : uint64_t plimit = GNUNET_MIN ((uint64_t) MAX_RECORDS,
114 : TALER_MERCHANTDB_abs_limit (limit));
115 0 : struct LookupProductGroupsContext plc = {
116 : .cb = cb,
117 : .cb_cls = cb_cls,
118 : /* Can be overwritten by the lookup_product_groups_cb */
119 : .extract_failed = false,
120 : };
121 0 : struct GNUNET_PQ_QueryParam params[] = {
122 0 : GNUNET_PQ_query_param_uint64 (&offset),
123 0 : GNUNET_PQ_query_param_uint64 (&plimit),
124 : GNUNET_PQ_query_param_end
125 : };
126 : enum GNUNET_DB_QueryStatus qs;
127 :
128 0 : GNUNET_assert (NULL != pg->current_merchant_id);
129 0 : GNUNET_assert (0 == strcmp (instance_id,
130 : pg->current_merchant_id));
131 0 : if (limit > 0)
132 : {
133 0 : TMH_PQ_prepare_anon (pg,
134 : "SELECT"
135 : " product_group_serial"
136 : " ,product_group_name"
137 : " ,product_group_description"
138 : " FROM merchant_product_groups"
139 : " WHERE product_group_serial > $1"
140 : " ORDER BY product_group_serial ASC"
141 : " LIMIT $2");
142 : }
143 : else
144 : {
145 0 : TMH_PQ_prepare_anon (pg,
146 : "SELECT"
147 : " product_group_serial"
148 : " ,product_group_name"
149 : " ,product_group_description"
150 : " FROM merchant_product_groups"
151 : " WHERE product_group_serial < $1"
152 : " ORDER BY product_group_serial DESC"
153 : " LIMIT $2");
154 : }
155 0 : qs = GNUNET_PQ_eval_prepared_multi_select (
156 : pg->conn,
157 : "",
158 : params,
159 : &lookup_product_groups_cb,
160 : &plc);
161 : /* If there was an error inside lookup_product_groups_cb, return a hard error. */
162 0 : if (plc.extract_failed)
163 : {
164 0 : GNUNET_break (0);
165 0 : return GNUNET_DB_STATUS_HARD_ERROR;
166 : }
167 0 : return qs;
168 : }
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