merchant

Merchant backend to process payments, run by merchants
Log | Files | Refs | Submodules | README | LICENSE

helper.h (4846B)


      1 /*
      2    This file is part of TALER
      3    Copyright (C) 2023 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/helper.h
     18  * @brief shared internal definitions for postgres logic
     19  * @author Christian Grothoff
     20  */
     21 #ifndef HELPER_H
     22 #define HELPER_H
     23 
     24 #include <gnunet/gnunet_util_lib.h>
     25 #include <gnunet/gnunet_db_lib.h>
     26 #include <gnunet/gnunet_time_lib.h>
     27 #include <taler/taler_util.h>
     28 
     29 /**
     30  * Type of the "cls" argument given to each of the functions in
     31  * our API.
     32  */
     33 struct TALER_MERCHANTDB_PostgresContext
     34 {
     35 
     36   /**
     37    * Postgres connection handle.
     38    */
     39   struct GNUNET_PQ_Context *conn;
     40 
     41   /**
     42    * Directory with SQL statements to run to create tables.
     43    */
     44   char *sql_dir;
     45 
     46   /**
     47    * Underlying configuration.
     48    */
     49   const struct GNUNET_CONFIGURATION_Handle *cfg;
     50 
     51   /**
     52    * Name of the currently active transaction, NULL if none is active.
     53    */
     54   const char *transaction_name;
     55 
     56   /**
     57    * Instance id ("merchant_id") that the search_path is currently
     58    * pointing at, or NULL if no per-instance schema is selected.
     59    * Owned by this struct; set by TALER_MERCHANTDB_set_instance().
     60    */
     61   char *current_merchant_id;
     62 
     63   /**
     64    * merchant_serial corresponding to @e current_merchant_id, or 0
     65    * if no per-instance schema is selected.  Used as the suffix in
     66    * per-instance prepared-statement names.
     67    */
     68   uint64_t current_merchant_serial;
     69 
     70   /**
     71    * Public key of the currently selected instance.  Populated by
     72    * TALER_MERCHANTDB_set_instance() together with @e current_merchant_id
     73    * and @e current_merchant_serial.  Used by call sites that emit
     74    * cross-process events (e.g. order-pay notifications) which carry the
     75    * instance public key in their payload.
     76    */
     77   struct TALER_MerchantPublicKeyP current_merchant_pub;
     78 
     79   /**
     80    * How many times have we connected to the DB.
     81    */
     82   uint64_t prep_gen;
     83 
     84 };
     85 
     86 
     87 /**
     88  * Prepares SQL statement @a sql under @a name for
     89  * connection @a pg once.
     90  * Returns with #GNUNET_DB_STATUS_HARD_ERROR on failure.
     91  *
     92  * @param pg a `struct TALER_MERCHANTDB_PostgresContext`
     93  * @param name name to prepare the statement under
     94  * @param sql actual SQL text
     95  */
     96 #define PREPARE(pg,name,sql)                      \
     97         do {                                            \
     98           static unsigned long long gen;                \
     99                                                   \
    100           if (gen < pg->prep_gen)                       \
    101           {                                             \
    102             struct GNUNET_PQ_PreparedStatement ps[] = { \
    103               GNUNET_PQ_make_prepare (name, sql),       \
    104               GNUNET_PQ_PREPARED_STATEMENT_END          \
    105             };                                          \
    106                                                   \
    107             if (GNUNET_OK !=                            \
    108                 GNUNET_PQ_prepare_statements (pg->conn, \
    109                                               ps))      \
    110             {                                           \
    111               GNUNET_break (0);                         \
    112               return GNUNET_DB_STATUS_HARD_ERROR;       \
    113             }                                           \
    114             gen = pg->prep_gen;                         \
    115           }                                             \
    116         } while (0)
    117 
    118 
    119 /**
    120  * Prepares SQL statement @a sql under no name ("") for
    121  * connection @a pg.  Useful for prepared statements that
    122  * should not be cached.
    123  * Returns with #GNUNET_DB_STATUS_HARD_ERROR on failure.
    124  *
    125  * @param pg a `struct TALER_MERCHANTDB_PostgresContext`
    126  * @param sql actual SQL text
    127  */
    128 #define TMH_PQ_prepare_anon(pg,sql)              \
    129         do {                                     \
    130           if (GNUNET_OK !=                       \
    131               GNUNET_PQ_prepare_anon (pg->conn,  \
    132                                       sql)) {    \
    133             GNUNET_break (0);                    \
    134             return GNUNET_DB_STATUS_HARD_ERROR;  \
    135           } } while (0)
    136 
    137 
    138 /**
    139  * Check that the database connection is still up and automatically reconnects
    140  * unless we are already inside of a transaction.
    141  *
    142  * @param pg connection to check
    143  */
    144 void
    145 TALER_MERCHANTDB_check_connection (
    146   struct TALER_MERCHANTDB_PostgresContext *pg);
    147 
    148 
    149 #endif