merchant

Merchant backend to process payments, run by merchants
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pg_lookup_products.c (6282B)


      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 backenddb/pg_lookup_products.c
     18  * @brief Implementation of the lookup_products function for Postgres
     19  * @author Iván Ávalos
     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 "pg_lookup_products.h"
     26 #include "pg_helper.h"
     27 
     28 /**
     29  * Context used for TMH_PG_lookup_products().
     30  */
     31 struct LookupProductsContext
     32 {
     33   /**
     34    * Function to call with the results.
     35    */
     36   TALER_MERCHANTDB_ProductsCallback cb;
     37 
     38   /**
     39    * Closure for @a cb.
     40    */
     41   void *cb_cls;
     42 
     43   /**
     44    * Did database result extraction fail?
     45    */
     46   bool extract_failed;
     47 };
     48 
     49 
     50 /**
     51  * Function to be called with the results of a SELECT statement
     52  * that has returned @a num_results results about products.
     53  *
     54  * @param[in,out] cls of type `struct LookupProductsContext *`
     55  * @param result the postgres result
     56  * @param num_results the number of results in @a result
     57  */
     58 static void
     59 lookup_products_cb (void *cls,
     60                     PGresult *result,
     61                     unsigned int num_results)
     62 {
     63   struct LookupProductsContext *plc = cls;
     64 
     65   for (unsigned int i = 0; i < num_results; i++)
     66   {
     67     char *product_id;
     68     uint64_t product_serial;
     69     struct GNUNET_PQ_ResultSpec rs[] = {
     70       GNUNET_PQ_result_spec_string ("product_id",
     71                                     &product_id),
     72       GNUNET_PQ_result_spec_uint64 ("product_serial",
     73                                     &product_serial),
     74       GNUNET_PQ_result_spec_end
     75     };
     76 
     77     if (GNUNET_OK !=
     78         GNUNET_PQ_extract_result (result,
     79                                   rs,
     80                                   i))
     81     {
     82       GNUNET_break (0);
     83       plc->extract_failed = true;
     84       return;
     85     }
     86     plc->cb (plc->cb_cls,
     87              product_serial,
     88              product_id);
     89     GNUNET_PQ_cleanup_result (rs);
     90   }
     91 }
     92 
     93 
     94 enum GNUNET_DB_QueryStatus
     95 TMH_PG_lookup_products (void *cls,
     96                         const char *instance_id,
     97                         uint64_t offset,
     98                         int64_t limit,
     99                         const char *category_filter,
    100                         const char *name_filter,
    101                         const char *description_filter,
    102                         TALER_MERCHANTDB_ProductsCallback cb,
    103                         void *cb_cls)
    104 {
    105   struct PostgresClosure *pg = cls;
    106   uint64_t plimit = (uint64_t) ((limit < 0) ? -limit : limit);
    107   struct LookupProductsContext plc = {
    108     .cb = cb,
    109     .cb_cls = cb_cls,
    110     /* Can be overwritten by the lookup_products_cb */
    111     .extract_failed = false,
    112   };
    113   struct GNUNET_PQ_QueryParam params[] = {
    114     GNUNET_PQ_query_param_string (instance_id),
    115     GNUNET_PQ_query_param_uint64 (&offset),
    116     NULL == category_filter
    117     ? GNUNET_PQ_query_param_null ()
    118     : GNUNET_PQ_query_param_string (category_filter),
    119     NULL == name_filter
    120     ? GNUNET_PQ_query_param_null ()
    121     : GNUNET_PQ_query_param_string (name_filter),
    122     NULL == description_filter
    123     ? GNUNET_PQ_query_param_null ()
    124     : GNUNET_PQ_query_param_string (description_filter),
    125     GNUNET_PQ_query_param_uint64 (&plimit),
    126     GNUNET_PQ_query_param_end
    127   };
    128   enum GNUNET_DB_QueryStatus qs;
    129 
    130   check_connection (pg);
    131   PREPARE (pg,
    132            "lookup_products_asc",
    133            "SELECT"
    134            "  product_id"
    135            " ,product_serial"
    136            " FROM merchant_inventory"
    137            " JOIN merchant_instances"
    138            "   USING (merchant_serial)"
    139            " WHERE merchant_instances.merchant_id=$1"
    140            "   AND product_serial > $2"
    141            "   AND ( ($3::TEXT IS NULL) OR"
    142            "         (product_serial IN"
    143            "          (SELECT product_serial"
    144            "             FROM merchant_product_categories"
    145            "            WHERE category_serial IN"
    146            "               (SELECT category_serial"
    147            "                  FROM merchant_categories"
    148            "                 WHERE category_name LIKE LOWER($3)))) )"
    149            "   AND ( ($4::TEXT IS NULL) OR"
    150            "         (product_name LIKE LOWER($4)) )"
    151            "   AND ( ($5::TEXT IS NULL) OR"
    152            "         (description LIKE LOWER($5)) )"
    153            " ORDER BY product_serial ASC"
    154            " LIMIT $6");
    155   PREPARE (pg,
    156            "lookup_products_desc",
    157            "SELECT"
    158            "  product_id"
    159            " ,product_serial"
    160            " FROM merchant_inventory"
    161            " JOIN merchant_instances"
    162            "   USING (merchant_serial)"
    163            " WHERE merchant_instances.merchant_id=$1"
    164            "   AND product_serial < $2"
    165            "   AND ( ($3::TEXT IS NULL) OR"
    166            "         (product_serial IN"
    167            "          (SELECT product_serial"
    168            "             FROM merchant_product_categories"
    169            "            WHERE category_serial IN"
    170            "               (SELECT category_serial"
    171            "                  FROM merchant_categories"
    172            "                 WHERE category_name LIKE LOWER($3)))) )"
    173            "   AND ( ($4::TEXT IS NULL) OR"
    174            "         (product_name LIKE LOWER($4)) )"
    175            "   AND ( ($5::TEXT IS NULL) OR"
    176            "         (description LIKE LOWER($5)) )"
    177            " ORDER BY product_serial DESC"
    178            " LIMIT $6");
    179   qs = GNUNET_PQ_eval_prepared_multi_select (
    180     pg->conn,
    181     (limit > 0)
    182     ? "lookup_products_asc"
    183     : "lookup_products_desc",
    184     params,
    185     &lookup_products_cb,
    186     &plc);
    187   /* If there was an error inside lookup_products_cb, return a hard error. */
    188   if (plc.extract_failed)
    189   {
    190     GNUNET_break (0);
    191     return GNUNET_DB_STATUS_HARD_ERROR;
    192   }
    193   return qs;
    194 }