Line data    Source code

       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          11 : lookup_products_cb (void *cls,
      60             :                     PGresult *result,
      61             :                     unsigned int num_results)
      62             : {
      63          11 :   struct LookupProductsContext *plc = cls;
      64             : 
      65          13 :   for (unsigned int i = 0; i < num_results; i++)
      66             :   {
      67             :     char *product_id;
      68             :     uint64_t product_serial;
      69           2 :     struct GNUNET_PQ_ResultSpec rs[] = {
      70           2 :       GNUNET_PQ_result_spec_string ("product_id",
      71             :                                     &product_id),
      72           2 :       GNUNET_PQ_result_spec_uint64 ("product_serial",
      73             :                                     &product_serial),
      74             :       GNUNET_PQ_result_spec_end
      75             :     };
      76             : 
      77           2 :     if (GNUNET_OK !=
      78           2 :         GNUNET_PQ_extract_result (result,
      79             :                                   rs,
      80             :                                   i))
      81             :     {
      82           0 :       GNUNET_break (0);
      83           0 :       plc->extract_failed = true;
      84           0 :       return;
      85             :     }
      86           2 :     plc->cb (plc->cb_cls,
      87             :              product_serial,
      88             :              product_id);
      89           2 :     GNUNET_PQ_cleanup_result (rs);
      90             :   }
      91             : }
      92             : 
      93             : 
      94             : enum GNUNET_DB_QueryStatus
      95          11 : TMH_PG_lookup_products (void *cls,
      96             :                         const char *instance_id,
      97             :                         uint64_t offset,
      98             :                         int64_t limit,
      99             :                         TALER_MERCHANTDB_ProductsCallback cb,
     100             :                         void *cb_cls)
     101             : {
     102          11 :   struct PostgresClosure *pg = cls;
     103          11 :   uint64_t plimit = (uint64_t) ((limit < 0) ? -limit : limit);
     104          11 :   struct LookupProductsContext plc = {
     105             :     .cb = cb,
     106             :     .cb_cls = cb_cls,
     107             :     /* Can be overwritten by the lookup_products_cb */
     108             :     .extract_failed = false,
     109             :   };
     110          11 :   struct GNUNET_PQ_QueryParam params[] = {
     111          11 :     GNUNET_PQ_query_param_string (instance_id),
     112          11 :     GNUNET_PQ_query_param_uint64 (&offset),
     113          11 :     GNUNET_PQ_query_param_uint64 (&plimit),
     114             :     GNUNET_PQ_query_param_end
     115             :   };
     116             :   enum GNUNET_DB_QueryStatus qs;
     117             : 
     118          11 :   check_connection (pg);
     119          11 :   PREPARE (pg,
     120             :            "lookup_products_asc",
     121             :            "SELECT"
     122             :            "  product_id"
     123             :            " ,product_serial"
     124             :            " FROM merchant_inventory"
     125             :            " JOIN merchant_instances"
     126             :            "   USING (merchant_serial)"
     127             :            " WHERE merchant_instances.merchant_id=$1"
     128             :            "   AND product_serial > $2"
     129             :            " ORDER BY product_serial ASC"
     130             :            " LIMIT $3");
     131          11 :   PREPARE (pg,
     132             :            "lookup_products_desc",
     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             :            " ORDER BY product_serial DESC"
     142             :            " LIMIT $3");
     143          11 :   qs = GNUNET_PQ_eval_prepared_multi_select (
     144             :     pg->conn,
     145             :     (limit > 0)
     146             :     ? "lookup_products_asc"
     147             :     : "lookup_products_desc",
     148             :     params,
     149             :     &lookup_products_cb,
     150             :     &plc);
     151             :   /* If there was an error inside lookup_products_cb, return a hard error. */
     152          11 :   if (plc.extract_failed)
     153           0 :     return GNUNET_DB_STATUS_HARD_ERROR;
     154          11 :   return qs;
     155             : }