merchant

Merchant backend to process payments, run by merchants
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lookup_templates.c (3993B)

      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 src/backenddb/lookup_templates.c
     18  * @brief Implementation of the lookup_templates function for Postgres
     19  * @author Christian Grothoff
     20  */
     21 #include "platform.h"
     22 #include <taler/taler_error_codes.h>
     23 #include <taler/taler_dbevents.h>
     24 #include <taler/taler_pq_lib.h>
     25 #include "merchant-database/lookup_templates.h"
     26 #include "helper.h"
     27 
     28 
     29 /**
     30  * Context used for TALER_MERCHANTDB_lookup_templates().
     31  */
     32 struct LookupTemplateContext
     33 {
     34   /**
     35    * Function to call with the results.
     36    */
     37   TALER_MERCHANTDB_TemplatesCallback cb;
     38 
     39   /**
     40    * Closure for @a cb.
     41    */
     42   void *cb_cls;
     43 
     44   /**
     45    * Did database result extraction fail?
     46    */
     47   bool extract_failed;
     48 };
     49 
     50 
     51 /**
     52  * Function to be called with the results of a SELECT statement
     53  * that has returned @a num_results results about template.
     54  *
     55  * @param[in,out] cls of type `struct LookupTemplateContext *`
     56  * @param result the postgres result
     57  * @param num_results the number of results in @a result
     58  */
     59 static void
     60 lookup_templates_cb (void *cls,
     61                      PGresult *result,
     62                      unsigned int num_results)
     63 {
     64   struct LookupTemplateContext *tlc = cls;
     65 
     66   for (unsigned int i = 0; i < num_results; i++)
     67   {
     68     char *template_id;
     69     char *template_description;
     70     struct GNUNET_PQ_ResultSpec rs[] = {
     71       GNUNET_PQ_result_spec_string ("template_id",
     72                                     &template_id),
     73       GNUNET_PQ_result_spec_string ("template_description",
     74                                     &template_description),
     75       GNUNET_PQ_result_spec_end
     76     };
     77 
     78     if (GNUNET_OK !=
     79         GNUNET_PQ_extract_result (result,
     80                                   rs,
     81                                   i))
     82     {
     83       GNUNET_break (0);
     84       tlc->extract_failed = true;
     85       return;
     86     }
     87     tlc->cb (tlc->cb_cls,
     88              template_id,
     89              template_description);
     90     GNUNET_PQ_cleanup_result (rs);
     91   }
     92 }
     93 
     94 
     95 enum GNUNET_DB_QueryStatus
     96 TALER_MERCHANTDB_lookup_templates (struct TALER_MERCHANTDB_PostgresContext *pg,
     97                                    const char *instance_id,
     98                                    TALER_MERCHANTDB_TemplatesCallback cb,
     99                                    void *cb_cls)
    100 {
    101   struct LookupTemplateContext tlc = {
    102     .cb = cb,
    103     .cb_cls = cb_cls,
    104     /* Can be overwritten by the lookup_template_cb */
    105     .extract_failed = false,
    106   };
    107   struct GNUNET_PQ_QueryParam params[] = {
    108     GNUNET_PQ_query_param_string (instance_id),
    109     GNUNET_PQ_query_param_end
    110   };
    111   enum GNUNET_DB_QueryStatus qs;
    112 
    113   check_connection (pg);
    114   PREPARE (pg,
    115            "lookup_templates",
    116            "SELECT"
    117            " template_id"
    118            ",template_description"
    119            " FROM merchant_template"
    120            " JOIN merchant_instances"
    121            "   USING (merchant_serial)"
    122            " WHERE merchant_instances.merchant_id=$1");
    123   qs = GNUNET_PQ_eval_prepared_multi_select (pg->conn,
    124                                              "lookup_templates",
    125                                              params,
    126                                              &lookup_templates_cb,
    127                                              &tlc);
    128   /* If there was an error inside lookup_templates_cb, return a hard error. */
    129   if (tlc.extract_failed)
    130     return GNUNET_DB_STATUS_HARD_ERROR;
    131   return qs;
    132 }