use more specific SELECT in exchange aggregator on refunds instead of filtering in application logic later

src/exchange/taler-exchange-aggregator.c

@@ -133,11 +133,6 @@ struct AggregationUnit
    */
   struct GNUNET_HashCode h_wire;
 
-  /**
-   * Hash code of contract we are currently looking into.
-   */
-  const struct GNUNET_HashCode *h_contract;
-
   /**
    * Wire transfer identifier we use.
    */
@@ -678,36 +673,15 @@ exchange_serve_process_config ()
  * the aggregation unit's total amount.
  *
  * @param cls closure with a `struct AggregationUnit *`
- * @param merchant_pub public key of merchant who authorized refund
+ * @param amount_with_fee what was the refunded amount with the fee
- * @param merchant_sig signature of merchant authorizing refund
- * @param h_contract hash of contract being refunded
- * @param rtransaction_id refund transaction ID
- * @param amount_with_fee amount being refunded
- * @param refund_fee fee the exchange keeps for the refund processing
  * @return #GNUNET_OK to continue to iterate, #GNUNET_SYSERR to stop
  */
 static int
 refund_by_coin_cb (void *cls,
-                   const struct TALER_MerchantPublicKeyP *merchant_pub,
+                   const struct TALER_Amount *amount_with_fee)
-                   const struct TALER_MerchantSignatureP *merchant_sig,
-                   const struct GNUNET_HashCode *h_contract,
-                   uint64_t rtransaction_id,
-                   const struct TALER_Amount *amount_with_fee,
-                   const struct TALER_Amount *refund_fee)
 {
   struct AggregationUnit *aux = cls;
 
-  (void) merchant_sig;
-  (void) rtransaction_id;
-  (void) refund_fee;
-  /* TODO: potential optimization: include these conditions
-     in the SELECT, and avoid fetching the values we do not need! */
-  if (0 != GNUNET_memcmp (merchant_pub,
-                          &aux->merchant_pub))
-    return GNUNET_OK; /* different merchant */
-  if (0 != GNUNET_memcmp (h_contract,
-                          aux->h_contract))
-    return GNUNET_OK; /* different contract */
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
               "Aggregator subtracts applicable refund of amount %s\n",
               TALER_amount2s (amount_with_fee));
@@ -776,13 +750,13 @@ deposit_cb (void *cls,
               TALER_B2S (coin_pub),
               TALER_amount2s (&au->total_amount));
   au->row_id = row_id;
-  au->h_contract = h_contract_terms;
   qs = db_plugin->select_refunds_by_coin (db_plugin->cls,
                                           au->session,
                                           coin_pub,
+                                          &au->merchant_pub,
+                                          h_contract_terms,
                                           &refund_by_coin_cb,
                                           au);
-  au->h_contract = NULL;
   if (0 > qs)
   {
     GNUNET_break (GNUNET_DB_STATUS_SOFT_ERROR == qs);
@@ -938,13 +912,13 @@ aggregate_cb (void *cls,
     return GNUNET_DB_STATUS_SUCCESS_ONE_RESULT;
   }
 
-  au->h_contract = h_contract_terms;
   qs = db_plugin->select_refunds_by_coin (db_plugin->cls,
                                           au->session,
                                           coin_pub,
+                                          &au->merchant_pub,
+                                          h_contract_terms,
                                           &refund_by_coin_cb,
                                           au);
-  au->h_contract = NULL;
   if (0 > qs)
   {
     GNUNET_break (GNUNET_DB_STATUS_SOFT_ERROR == qs);

src/exchangedb/plugin_exchangedb_postgres.c

@@ -736,6 +736,17 @@ postgres_get_session (void *cls)
                               "    JOIN denominations denom USING (denom_pub_hash)"
                               " WHERE coin_pub=$1;",
                               1),
+      /* Query the 'refunds' by coin public key, merchant_pub and contract hash */
+      GNUNET_PQ_make_prepare ("get_refunds_by_coin_and_contract",
+                              "SELECT"
+                              " amount_with_fee_val"
+                              ",amount_with_fee_frac"
+                              " FROM refunds"
+                              " WHERE"
+                              "       coin_pub=$1"
+                              "   AND merchant_pub=$2"
+                              "   AND h_contract_terms=$3;",
+                              3),
       /* Fetch refunds with rowid '\geq' the given parameter */
       GNUNET_PQ_make_prepare ("audit_get_refunds_incr",
                               "SELECT"
@@ -3296,25 +3307,10 @@ get_refunds_cb (void *cls,
 
   for (unsigned int i = 0; i<num_results; i++)
   {
-    struct TALER_MerchantPublicKeyP merchant_pub;
-    struct TALER_MerchantSignatureP merchant_sig;
-    struct GNUNET_HashCode h_contract;
-    uint64_t rtransaction_id;
     struct TALER_Amount amount_with_fee;
-    struct TALER_Amount refund_fee;
     struct GNUNET_PQ_ResultSpec rs[] = {
-      GNUNET_PQ_result_spec_auto_from_type ("merchant_pub",
-                                            &merchant_pub),
-      GNUNET_PQ_result_spec_auto_from_type ("merchant_sig",
-                                            &merchant_sig),
-      GNUNET_PQ_result_spec_auto_from_type ("h_contract_terms",
-                                            &h_contract),
-      GNUNET_PQ_result_spec_uint64 ("rtransaction_id",
-                                    &rtransaction_id),
       TALER_PQ_RESULT_SPEC_AMOUNT ("amount_with_fee",
                                    &amount_with_fee),
-      TALER_PQ_RESULT_SPEC_AMOUNT ("fee_refund",
-                                   &refund_fee),
       GNUNET_PQ_result_spec_end
     };
 
@@ -3329,23 +3325,20 @@ get_refunds_cb (void *cls,
     }
     if (GNUNET_OK !=
         srctx->cb (srctx->cb_cls,
-                   &merchant_pub,
+                   &amount_with_fee))
-                   &merchant_sig,
-                   &h_contract,
-                   rtransaction_id,
-                   &amount_with_fee,
-                   &refund_fee))
       return;
   }
 }
 
 
 /**
- * Select refunds by @a coin_pub.
+ * Select refunds by @a coin_pub, @a merchant_pub and @a h_contract.
  *
  * @param cls closure of plugin
  * @param session database handle to use
  * @param coin_pub coin to get refunds for
+ * @param merchant_pub merchant to get refunds for
+ * @param h_contract_pub contract (hash) to get refunds for
  * @param cb function to call for each refund found
  * @param cb_cls closure for @a cb
  * @return query result status
@@ -3355,13 +3348,19 @@ postgres_select_refunds_by_coin (void *cls,
                                  struct TALER_EXCHANGEDB_Session *session,
                                  const struct
                                  TALER_CoinSpendPublicKeyP *coin_pub,
-                                 TALER_EXCHANGEDB_RefundCoinCallback cb,
+                                 const struct
+                                 TALER_MerchantPublicKeyP *merchant_pub,
+                                 const struct GNUNET_HashCode *h_contract,
+                                 TALER_EXCHANGEDB_RefundCoinCallback
+                                 cb,
                                  void *cb_cls)
 {
   struct PostgresClosure *pg = cls;
   enum GNUNET_DB_QueryStatus qs;
   struct GNUNET_PQ_QueryParam params[] = {
     GNUNET_PQ_query_param_auto_from_type (coin_pub),
+    GNUNET_PQ_query_param_auto_from_type (merchant_pub),
+    GNUNET_PQ_query_param_auto_from_type (h_contract),
     GNUNET_PQ_query_param_end
   };
   struct SelectRefundContext srctx = {
@@ -3372,7 +3371,7 @@ postgres_select_refunds_by_coin (void *cls,
   };
 
   qs = GNUNET_PQ_eval_prepared_multi_select (session->conn,
-                                             "get_refunds_by_coin",
+                                             "get_refunds_by_coin_and_contract",
                                              params,
                                              &get_refunds_cb,
                                              &srctx);

src/exchangedb/test_exchangedb.c

@@ -1412,60 +1412,21 @@ wire_missing_cb (void *cls,
  * to a particular coin.
  *
  * @param cls closure with the `struct TALER_EXCHANGEDB_Refund *` we expect to get
- * @param merchant_pub public key of merchant who authorized refund
- * @param merchant_sig signature of merchant authorizing refund
- * @param h_contract hash of contract being refunded
- * @param rtransaction_id refund transaction ID
  * @param amount_with_fee amount being refunded
- * @param refund_fee fee the exchange keeps for the refund processing
  * @return #GNUNET_OK to continue to iterate, #GNUNET_SYSERR to stop
  */
 static int
 check_refund_cb (void *cls,
-                 const struct TALER_MerchantPublicKeyP *merchant_pub,
+                 const struct TALER_Amount *amount_with_fee)
-                 const struct TALER_MerchantSignatureP *merchant_sig,
-                 const struct GNUNET_HashCode *h_contract,
-                 uint64_t rtransaction_id,
-                 const struct TALER_Amount *amount_with_fee,
-                 const struct TALER_Amount *refund_fee)
 {
   const struct TALER_EXCHANGEDB_Refund *refund = cls;
 
-  if (0 != GNUNET_memcmp (merchant_pub,
-                          &refund->details.merchant_pub))
-  {
-    GNUNET_break (0);
-    result = 66;
-  }
-  if (0 != GNUNET_memcmp (merchant_sig,
-                          &refund->details.merchant_sig))
-  {
-    GNUNET_break (0);
-    result = 66;
-  }
-  if (0 != GNUNET_memcmp (h_contract,
-                          &refund->details.h_contract_terms))
-  {
-    GNUNET_break (0);
-    result = 66;
-  }
-  if (rtransaction_id != refund->details.rtransaction_id)
-  {
-    GNUNET_break (0);
-    result = 66;
-  }
   if (0 != TALER_amount_cmp (amount_with_fee,
                              &refund->details.refund_amount))
   {
     GNUNET_break (0);
     result = 66;
   }
-  if (0 != TALER_amount_cmp (refund_fee,
-                             &refund->details.refund_fee))
-  {
-    GNUNET_break (0);
-    result = 66;
-  }
   return GNUNET_OK;
 }
 
@@ -1988,6 +1949,8 @@ run (void *cls)
           plugin->select_refunds_by_coin (plugin->cls,
                                           session,
                                           &refund.coin.coin_pub,
+                                          &refund.details.merchant_pub,
+                                          &refund.details.h_contract_terms,
                                           &check_refund_cb,
                                           &refund));
 

src/include/taler_exchangedb_plugin.h

@@ -1094,28 +1094,16 @@ typedef int
 
 /**
  * Callback invoked with information about refunds applicable
- * to a particular coin.
+ * to a particular coin and contract.
  *
  * @param cls closure
- * @param merchant_pub public key of merchant who authorized refund
- * @param merchant_sig signature of merchant authorizing refund
- * @param h_contract hash of contract being refunded
- * @param rtransaction_id refund transaction ID
  * @param amount_with_fee amount being refunded
- * @param refund_fee fee the exchange keeps for the refund processing
  * @return #GNUNET_OK to continue to iterate, #GNUNET_SYSERR to stop
  */
 typedef int
 (*TALER_EXCHANGEDB_RefundCoinCallback)(void *cls,
                                        const struct
-                                       TALER_MerchantPublicKeyP *merchant_pub,
+                                       TALER_Amount *amount_with_fee);
-                                       const struct
-                                       TALER_MerchantSignatureP *merchant_sig,
-                                       const struct GNUNET_HashCode *h_contract,
-                                       uint64_t rtransaction_id,
-                                       const struct
-                                       TALER_Amount *amount_with_fee,
-                                       const struct TALER_Amount *refund_fee);
 
 
 /**
@@ -1947,11 +1935,13 @@ struct TALER_EXCHANGEDB_Plugin
                    const struct TALER_EXCHANGEDB_Refund *refund);
 
   /**
-   * Select refunds by @a coin_pub.
+   * Select refunds by @a coin_pub, @a merchant_pub and @a h_contract.
    *
    * @param cls closure of plugin
    * @param session database handle to use
    * @param coin_pub coin to get refunds for
+   * @param merchant_pub merchant to get refunds for
+   * @param h_contract_pub contract (hash) to get refunds for
    * @param cb function to call for each refund found
    * @param cb_cls closure for @a cb
    * @return query result status
@@ -1960,6 +1950,8 @@ struct TALER_EXCHANGEDB_Plugin
   (*select_refunds_by_coin)(void *cls,
                             struct TALER_EXCHANGEDB_Session *session,
                             const struct TALER_CoinSpendPublicKeyP *coin_pub,
+                            const struct TALER_MerchantPublicKeyP *merchant_pub,
+                            const struct GNUNET_HashCode *h_contract,
                             TALER_EXCHANGEDB_RefundCoinCallback cb,
                             void *cb_cls);