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Base system with REST service to issue digital coins, run by the payment service provider
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pg_ensure_coin_known.c (5776B)


      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 exchangedb/pg_ensure_coin_known.c
     18  * @brief Implementation of the ensure_coin_known function for Postgres
     19  * @author Christian Grothoff
     20  */
     21 #include "taler/platform.h"
     22 #include "taler/taler_error_codes.h"
     23 #include "taler/taler_dbevents.h"
     24 #include "taler/taler_exchangedb_plugin.h"
     25 #include "taler/taler_pq_lib.h"
     26 #include "pg_ensure_coin_known.h"
     27 #include "pg_helper.h"
     28 
     29 
     30 enum TALER_EXCHANGEDB_CoinKnownStatus
     31 TEH_PG_ensure_coin_known (void *cls,
     32                           const struct TALER_CoinPublicInfo *coin,
     33                           uint64_t *known_coin_id,
     34                           struct TALER_DenominationHashP *denom_hash,
     35                           struct TALER_AgeCommitmentHashP *h_age_commitment)
     36 {
     37   struct PostgresClosure *pg = cls;
     38   enum GNUNET_DB_QueryStatus qs;
     39   bool existed;
     40   bool no_denom_pub_hash;
     41   bool no_age_commitment_hash;
     42   struct GNUNET_PQ_QueryParam params[] = {
     43     GNUNET_PQ_query_param_auto_from_type (&coin->coin_pub),
     44     GNUNET_PQ_query_param_auto_from_type (&coin->denom_pub_hash),
     45     coin->no_age_commitment
     46     ? GNUNET_PQ_query_param_null ()
     47     : GNUNET_PQ_query_param_auto_from_type (&coin->h_age_commitment),
     48     TALER_PQ_query_param_denom_sig (&coin->denom_sig),
     49     GNUNET_PQ_query_param_end
     50   };
     51   struct GNUNET_PQ_ResultSpec rs[] = {
     52     GNUNET_PQ_result_spec_bool ("existed",
     53                                 &existed),
     54     GNUNET_PQ_result_spec_uint64 ("known_coin_id",
     55                                   known_coin_id),
     56     GNUNET_PQ_result_spec_allow_null (
     57       GNUNET_PQ_result_spec_auto_from_type ("denom_pub_hash",
     58                                             denom_hash),
     59       &no_denom_pub_hash),
     60     GNUNET_PQ_result_spec_allow_null (
     61       GNUNET_PQ_result_spec_auto_from_type ("age_commitment_hash",
     62                                             h_age_commitment),
     63       &no_age_commitment_hash),
     64     GNUNET_PQ_result_spec_end
     65   };
     66 
     67   /*
     68      See also:
     69      https://stackoverflow.com/questions/34708509/how-to-use-returning-with-on-conflict-in-postgresql/37543015#37543015
     70   */
     71   PREPARE (pg,
     72            "insert_known_coin",
     73            "WITH dd"
     74            "  (denominations_serial"
     75            "  ,coin"
     76            "  ) AS ("
     77            "    SELECT "
     78            "       denominations_serial"
     79            "      ,coin"
     80            "        FROM denominations"
     81            "        WHERE denom_pub_hash=$2"
     82            "  ), input_rows"
     83            "    (coin_pub) AS ("
     84            "      VALUES ($1::BYTEA)"
     85            "  ), ins AS ("
     86            "  INSERT INTO known_coins "
     87            "  (coin_pub"
     88            "  ,denominations_serial"
     89            "  ,age_commitment_hash"
     90            "  ,denom_sig"
     91            "  ,remaining"
     92            "  ) SELECT "
     93            "     $1"
     94            "    ,denominations_serial"
     95            "    ,$3"
     96            "    ,$4"
     97            "    ,coin"
     98            "  FROM dd"
     99            "  ON CONFLICT DO NOTHING" /* CONFLICT on (coin_pub) */
    100            "  RETURNING "
    101            "     known_coin_id"
    102            "  ) "
    103            "SELECT "
    104            "   FALSE AS existed"
    105            "  ,known_coin_id"
    106            "  ,NULL AS denom_pub_hash"
    107            "  ,NULL AS age_commitment_hash"
    108            "  FROM ins "
    109            "UNION ALL "
    110            "SELECT "
    111            "   TRUE AS existed"
    112            "  ,known_coin_id"
    113            "  ,denom_pub_hash"
    114            "  ,kc.age_commitment_hash"
    115            "  FROM input_rows"
    116            "  JOIN known_coins kc USING (coin_pub)"
    117            "  JOIN denominations USING (denominations_serial)"
    118            "  LIMIT 1");
    119   qs = GNUNET_PQ_eval_prepared_singleton_select (pg->conn,
    120                                                  "insert_known_coin",
    121                                                  params,
    122                                                  rs);
    123   switch (qs)
    124   {
    125   case GNUNET_DB_STATUS_HARD_ERROR:
    126     GNUNET_break (0);
    127     return TALER_EXCHANGEDB_CKS_HARD_FAIL;
    128   case GNUNET_DB_STATUS_SOFT_ERROR:
    129     return TALER_EXCHANGEDB_CKS_SOFT_FAIL;
    130   case GNUNET_DB_STATUS_SUCCESS_NO_RESULTS:
    131     GNUNET_break (0); /* should be impossible */
    132     return TALER_EXCHANGEDB_CKS_HARD_FAIL;
    133   case GNUNET_DB_STATUS_SUCCESS_ONE_RESULT:
    134     if (! existed)
    135       return TALER_EXCHANGEDB_CKS_ADDED;
    136     break; /* continued below */
    137   }
    138 
    139   if ( (! no_denom_pub_hash) &&
    140        (0 != GNUNET_memcmp (denom_hash,
    141                             &coin->denom_pub_hash)) )
    142   {
    143     GNUNET_break_op (0);
    144     return TALER_EXCHANGEDB_CKS_DENOM_CONFLICT;
    145   }
    146 
    147   if (no_age_commitment_hash != coin->no_age_commitment)
    148   {
    149     if (no_age_commitment_hash)
    150     {
    151       GNUNET_break_op (0);
    152       return TALER_EXCHANGEDB_CKS_AGE_CONFLICT_EXPECTED_NULL;
    153     }
    154     else
    155     {
    156       GNUNET_break_op (0);
    157       return TALER_EXCHANGEDB_CKS_AGE_CONFLICT_EXPECTED_NON_NULL;
    158     }
    159   }
    160   else if ( (! no_age_commitment_hash) &&
    161             (0 != GNUNET_memcmp (h_age_commitment,
    162                                  &coin->h_age_commitment)) )
    163   {
    164     GNUNET_break_op (0);
    165     return TALER_EXCHANGEDB_CKS_AGE_CONFLICT_VALUE_DIFFERS;
    166   }
    167 
    168   return TALER_EXCHANGEDB_CKS_PRESENT;
    169 }