From 057ac0fa95c29421b3868f43696023af3ec4cdd6 Mon Sep 17 00:00:00 2001
From: Christian Grothoff <christian@grothoff.org>
Date: Thu, 25 Jun 2020 17:27:49 +0200
Subject: logic to update 'wired' status of an order

---
 src/backenddb/plugin_merchantdb_postgres.c | 85 +++++++++++++++++++++++++++++-
 1 file changed, 83 insertions(+), 2 deletions(-)

(limited to 'src/backenddb')

diff --git a/src/backenddb/plugin_merchantdb_postgres.c b/src/backenddb/plugin_merchantdb_postgres.c
index ba08d934..efb58918 100644
--- a/src/backenddb/plugin_merchantdb_postgres.c
+++ b/src/backenddb/plugin_merchantdb_postgres.c
@@ -214,6 +214,41 @@ postgres_start (void *cls,
 }
 
 
+/**
+ * Start a transaction in 'read committed' mode.
+ *
+ * @param cls the `struct PostgresClosure` with the plugin-specific state
+ * @param name unique name identifying the transaction (for debugging),
+ *             must point to a constant
+ * @return #GNUNET_OK on success
+ */
+static int
+postgres_start_read_committed (void *cls,
+                               const char *name)
+{
+  struct PostgresClosure *pg = cls;
+  struct GNUNET_PQ_ExecuteStatement es[] = {
+    GNUNET_PQ_make_execute ("START TRANSACTION ISOLATION LEVEL READ COMMITTED"),
+    GNUNET_PQ_EXECUTE_STATEMENT_END
+  };
+
+  check_connection (pg);
+  postgres_preflight (pg);
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Starting merchant DB transaction (READ COMMITTED)\n");
+  if (GNUNET_OK !=
+      GNUNET_PQ_exec_statements (pg->conn,
+                                 es))
+  {
+    TALER_LOG_ERROR ("Failed to start transaction\n");
+    GNUNET_break (0);
+    return GNUNET_SYSERR;
+  }
+  pg->transaction_name = name;
+  return GNUNET_OK;
+}
+
+
 /**
  * Roll back the current transaction of a database connection.
  *
@@ -3226,8 +3261,8 @@ RETRY:
   if (MAX_RETRIES < ++retries)
     return GNUNET_DB_STATUS_SOFT_ERROR;
   if (GNUNET_OK !=
-      postgres_start (pg,
-                      "insert transfer details"))
+      postgres_start_read_committed (pg,
+                                     "insert transfer details"))
   {
     GNUNET_break (0);
     return GNUNET_DB_STATUS_HARD_ERROR;
@@ -3320,6 +3355,30 @@ RETRY:
       return qs;
     }
   }
+  /* Update merchant_contract_terms 'wired' status: for all coins
+     that were wired, set the respective order's "wired" status to
+     true, *if* all other deposited coins associated with that order
+     have also been wired (this time or earlier) */
+  for (unsigned int i = 0; i<td->details_length; i++)
+  {
+    const struct TALER_TrackTransferDetails *d = &td->details[i];
+    struct GNUNET_PQ_QueryParam params[] = {
+      GNUNET_PQ_query_param_auto_from_type (&d->coin_pub),
+      GNUNET_PQ_query_param_end
+    };
+
+    qs = GNUNET_PQ_eval_prepared_non_select (pg->conn,
+                                             "update_wired_by_coin_pub",
+                                             params);
+    if (0 > qs)
+    {
+      GNUNET_break (GNUNET_DB_STATUS_SOFT_ERROR == qs);
+      postgres_rollback (pg);
+      if (GNUNET_DB_STATUS_SOFT_ERROR == qs)
+        goto RETRY;
+      return qs;
+    }
+  }
   qs = postgres_commit (pg);
   if (GNUNET_DB_STATUS_SUCCESS_NO_RESULTS == qs)
     return GNUNET_DB_STATUS_SUCCESS_ONE_RESULT;
@@ -7425,6 +7484,27 @@ libtaler_plugin_merchantdb_postgres_init (void *cls)
                             " WHERE coin_pub=$7"
                             "   AND h_contract_terms=$8",
                             8),
+    /* for postgres_insert_transfer_details() */
+    GNUNET_PQ_make_prepare ("update_wired_by_coin_pub",
+                            "WITH os AS" /* select orders affected by the coin */
+                            "(SELECT order_serial"
+                            "   FROM merchant_deposits"
+                            "  WHERE coin_pub=$1)"
+                            "UPDATE merchant_contract_terms "
+                            " SET wired=TRUE "
+                            " WHERE order_serial IN "
+                            "  (SELECT order_serial FROM merchant_deposits" /* only orders for which NO un-wired coin exists*/
+                            "    WHERE NOT EXISTS "
+                            "    (SELECT order_serial FROM merchant_deposits" /* orders for which ANY un-wired coin exists */
+                            "       JOIN os USING (order_serial)" /* filter early */
+                            "      WHERE deposit_serial NOT IN"
+                            "      (SELECT deposit_serial " /* all coins associated with order that WERE wired */
+                            "         FROM merchant_deposits "
+                            "         JOIN os USING (order_serial)" /* filter early */
+                            "         JOIN merchant_deposit_to_transfer USING (deposit_serial)"
+                            "         JOIN merchant_transfers USING (credit_serial)"
+                            "        WHERE confirmed=TRUE)))",
+                            1),
     /* for postgres_lookup_wire_fee() */
     GNUNET_PQ_make_prepare ("lookup_wire_fee",
                             "SELECT"
@@ -8206,6 +8286,7 @@ libtaler_plugin_merchantdb_postgres_init (void *cls)
   plugin->drop_tables = &postgres_drop_tables;
   plugin->preflight = &postgres_preflight;
   plugin->start = &postgres_start;
+  plugin->start_read_committed = &postgres_start_read_committed;
   plugin->rollback = &postgres_rollback;
   plugin->commit = &postgres_commit;
   plugin->lookup_instances = &postgres_lookup_instances;
-- 
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