merchant

Merchant backend to process payments, run by merchants
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select_exchanges.c (4351B)

      1 /*
      2    This file is part of TALER
      3    Copyright (C) 2026 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/select_exchanges.c
     18  * @brief Implementation of the select_exchanges function for Postgres
     19  * @author Christian Grothoff
     20  */
     21 #include "platform.h"
     22 #include <taler/taler_pq_lib.h>
     23 #include "merchant-database/select_exchanges.h"
     24 #include "helper.h"
     25 
     26 /**
     27  * Context used for TALER_MERCHANTDB_lookup_exchanges().
     28  */
     29 struct LookupExchangesContext
     30 {
     31   /**
     32    * Function to call with the results.
     33    */
     34   TALER_MERCHANTDB_ExchangesCallback cb;
     35 
     36   /**
     37    * Closure for @a cb.
     38    */
     39   void *cb_cls;
     40 
     41   /**
     42    * Did database result extraction fail?
     43    */
     44   bool extract_failed;
     45 };
     46 
     47 
     48 /**
     49  * Function to be called with the results of a SELECT statement
     50  * that has returned @a num_results results about product exchanges.
     51  *
     52  * @param[in,out] cls of type `struct LookupExchangesContext *`
     53  * @param result the postgres result
     54  * @param num_results the number of results in @a result
     55  */
     56 static void
     57 lookup_exchanges_cb (void *cls,
     58                      PGresult *result,
     59                      unsigned int num_results)
     60 {
     61   struct LookupExchangesContext *plc = cls;
     62 
     63   for (unsigned int i = 0; i < num_results; i++)
     64   {
     65     char *exchange_url;
     66     json_t *keys = NULL;
     67     struct GNUNET_TIME_Absolute next_download;
     68     struct GNUNET_TIME_Absolute keys_expiration;
     69     uint32_t hc;
     70     uint32_t ec;
     71     struct GNUNET_PQ_ResultSpec rs[] = {
     72       GNUNET_PQ_result_spec_absolute_time ("first_retry",
     73                                            &next_download),
     74       GNUNET_PQ_result_spec_absolute_time ("expiration_time",
     75                                            &keys_expiration),
     76       GNUNET_PQ_result_spec_string ("exchange_url",
     77                                     &exchange_url),
     78       GNUNET_PQ_result_spec_allow_null (
     79         TALER_PQ_result_spec_json ("keys_json",
     80                                    &keys),
     81         NULL),
     82       GNUNET_PQ_result_spec_uint32 ("exchange_http_status",
     83                                     &hc),
     84       GNUNET_PQ_result_spec_uint32 ("exchange_ec_code",
     85                                     &ec),
     86       GNUNET_PQ_result_spec_end
     87     };
     88 
     89     if (GNUNET_OK !=
     90         GNUNET_PQ_extract_result (result,
     91                                   rs,
     92                                   i))
     93     {
     94       GNUNET_break (0);
     95       plc->extract_failed = true;
     96       return;
     97     }
     98     plc->cb (plc->cb_cls,
     99              exchange_url,
    100              keys,
    101              next_download,
    102              keys_expiration,
    103              (unsigned int) hc,
    104              (enum TALER_ErrorCode) ec);
    105     GNUNET_PQ_cleanup_result (rs);
    106   }
    107 }
    108 
    109 
    110 enum GNUNET_DB_QueryStatus
    111 TALER_MERCHANTDB_select_exchanges (
    112   struct TALER_MERCHANTDB_PostgresContext *pg,
    113   TALER_MERCHANTDB_ExchangesCallback cb,
    114   void *cb_cls)
    115 {
    116   struct LookupExchangesContext plc = {
    117     .cb = cb,
    118     .cb_cls = cb_cls,
    119     /* Can be overwritten by the lookup_exchanges_cb */
    120     .extract_failed = false,
    121   };
    122   struct GNUNET_PQ_QueryParam params[] = {
    123     GNUNET_PQ_query_param_end
    124   };
    125   enum GNUNET_DB_QueryStatus qs;
    126 
    127   check_connection (pg);
    128   PREPARE (pg,
    129            "select_exchanges",
    130            "SELECT"
    131            "  exchange_url"
    132            " ,first_retry"
    133            " ,expiration_time"
    134            " ,keys_json::TEXT"
    135            " ,exchange_http_status"
    136            " ,exchange_ec_code"
    137            " FROM merchant.merchant_exchange_keys");
    138   qs = GNUNET_PQ_eval_prepared_multi_select (
    139     pg->conn,
    140     "select_exchanges",
    141     params,
    142     &lookup_exchanges_cb,
    143     &plc);
    144   /* If there was an error inside lookup_exchanges_cb, return a hard error. */
    145   if (plc.extract_failed)
    146   {
    147     GNUNET_break (0);
    148     return GNUNET_DB_STATUS_HARD_ERROR;
    149   }
    150   return qs;
    151 }