pg_helper.h (5052B)
1 /* 2 This file is part of TALER 3 Copyright (C) 2022 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 pg_helper.h 18 * @brief shared internal definitions for postgres DB plugin 19 * @author Christian Grothoff 20 */ 21 #ifndef PG_HELPER_H 22 #define PG_HELPER_H 23 24 25 #include "auditordb_lib.h" 26 27 /** 28 * Postgres database connection handle. 29 */ 30 struct TALER_AUDITORDB_PostgresContext 31 { 32 33 /** 34 * Postgres connection handle. 35 */ 36 struct GNUNET_PQ_Context *conn; 37 38 /** 39 * Name of the ongoing transaction, used to debug cases where 40 * a transaction is not properly terminated via COMMIT or 41 * ROLLBACK. 42 */ 43 const char *transaction_name; 44 45 /** 46 * Our configuration. 47 */ 48 const struct GNUNET_CONFIGURATION_Handle *cfg; 49 /** 50 * How often have we connected to the DB so far? 51 */ 52 unsigned long long prep_gen; 53 54 /** 55 * Which currency should we assume all amounts to be in? 56 */ 57 char *currency; 58 }; 59 60 61 // FIXME: comment 62 const char * 63 TALER_AUDITORDB_get_deletable_suppressable_table_name ( 64 enum TALER_AUDITORDB_DeletableSuppressableTables table); 65 66 67 /** 68 * Convert the signed @a limit of a monitoring listing into the row 69 * limit to pass to SQL. The sign selects the iteration direction and 70 * the magnitude the number of rows, but computing `-limit` directly is 71 * undefined behaviour for `INT64_MIN`, and the resulting value would 72 * reach Postgres as `LIMIT -9223372036854775808`, which errors out. 73 * `INT64_MIN` is therefore saturated to `INT64_MAX`. 74 * 75 * @param limit signed limit as given by the caller 76 * @return absolute value of @a limit, without signed overflow 77 */ 78 static inline uint64_t 79 TALER_AUDITORDB_abs_limit (int64_t limit) 80 { 81 /* Postgres binds INT8 as a *signed* 64-bit integer, so a magnitude 82 above INT64_MAX would reach LIMIT as a negative number. */ 83 if (INT64_MIN == limit) 84 return (uint64_t) INT64_MAX; 85 if (limit < 0) 86 return (uint64_t) -limit; 87 return (uint64_t) limit; 88 } 89 90 91 /** 92 * Prepares SQL statement @a sql under @a name for 93 * connection @a pg once. 94 * Returns with #GNUNET_DB_STATUS_HARD_ERROR on failure. 95 * 96 * @param pg a `struct PostgresClosure` 97 * @param name name to prepare the statement under 98 * @param sql actual SQL text 99 */ 100 #define PREPARE(pg,name,sql) \ 101 do { \ 102 static struct { \ 103 unsigned long long cnt; \ 104 struct TALER_AUDITORDB_PostgresContext *pg; \ 105 } preps_[2]; /* 2 ctrs for taler-auditor-sync*/ \ 106 unsigned int off_ = 0; \ 107 \ 108 while ( (NULL != preps_[off_].pg) && \ 109 (pg != preps_[off_].pg) && \ 110 (off_ < sizeof(preps_) / sizeof(*preps_)) ) \ 111 off_++; \ 112 GNUNET_assert (off_ < \ 113 sizeof(preps_) / sizeof(*preps_)); \ 114 if (preps_[off_].cnt < pg->prep_gen) \ 115 { \ 116 struct GNUNET_PQ_PreparedStatement ps[] = { \ 117 GNUNET_PQ_make_prepare (name, sql), \ 118 GNUNET_PQ_PREPARED_STATEMENT_END \ 119 }; \ 120 \ 121 if (GNUNET_OK != \ 122 GNUNET_PQ_prepare_statements (pg->conn, \ 123 ps)) \ 124 { \ 125 GNUNET_break (0); \ 126 return GNUNET_DB_STATUS_HARD_ERROR; \ 127 } \ 128 preps_[off_].pg = pg; \ 129 preps_[off_].cnt = pg->prep_gen; \ 130 } \ 131 } while (0) 132 133 134 /** 135 * Wrapper macro to add the currency from the plugin's state 136 * when fetching amounts from the database. 137 * 138 * @param field name of the database field to fetch amount from 139 * @param[out] amountp pointer to amount to set 140 */ 141 #define TALER_PQ_RESULT_SPEC_AMOUNT(field, \ 142 amountp) \ 143 TALER_PQ_result_spec_amount ( \ 144 field,pg->currency,amountp) 145 146 147 #endif