1 files changed, 138 insertions, 0 deletions
diff --git a/src/backenddb/pg_helper.c b/src/backenddb/pg_helper.c
new file mode 100644
index 00000000..802abc21
--- /dev/null
+++ b/src/backenddb/pg_helper.c
@@ -0,0 +1,138 @@
+/*
+   This file is part of TALER
+   Copyright (C) 2023 Taler Systems SA
+
+   TALER is free software; you can redistribute it and/or modify it under the
+   terms of the GNU General Public License as published by the Free Software
+   Foundation; either version 3, or (at your option) any later version.
+
+   TALER is distributed in the hope that it will be useful, but WITHOUT ANY
+   WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+   A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along with
+   TALER; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+ */
+/**
+ * @file pg_helper.c
+ * @brief shared internal definitions for postgres DB plugin
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include "pg_helper.h"
+#include <gnunet/gnunet_util_lib.h>
+#include <gnunet/gnunet_pq_lib.h>
+#include <taler/taler_util.h>
+#include <taler/taler_pq_lib.h>
+#include <taler/taler_json_lib.h>
+#include <taler/taler_mhd_lib.h>
+
+
+enum GNUNET_GenericReturnValue
+TMH_PG_start (void *cls,
+              const char *name)
+{
+  struct PostgresClosure *pg = cls;
+  struct GNUNET_PQ_ExecuteStatement es[] = {
+    GNUNET_PQ_make_execute ("START TRANSACTION ISOLATION LEVEL SERIALIZABLE"),
+    GNUNET_PQ_EXECUTE_STATEMENT_END
+  };
+
+  GNUNET_assert (NULL != name);
+  check_connection (pg);
+  postgres_preflight (pg);
+  GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+              "Starting merchant DB transaction `%s'\n",
+              name);
+  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;
+}
+
+
+enum GNUNET_GenericReturnValue
+TMH_PG_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
+  };
+
+  GNUNET_assert (NULL != name);
+  check_connection (pg);
+  postgres_preflight (pg);
+  GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+              "Starting merchant DB transaction %s (READ COMMITTED)\n",
+              name);
+  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;
+}
+
+
+void
+TMH_PG_rollback (void *cls)
+{
+  struct PostgresClosure *pg = cls;
+  struct GNUNET_PQ_ExecuteStatement es[] = {
+    GNUNET_PQ_make_execute ("ROLLBACK"),
+    GNUNET_PQ_EXECUTE_STATEMENT_END
+  };
+
+  if (NULL == pg->transaction_name)
+    return;
+  GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+              "Rolling back merchant DB transaction `%s'\n",
+              pg->transaction_name);
+  GNUNET_break (GNUNET_OK ==
+                GNUNET_PQ_exec_statements (pg->conn,
+                                           es));
+  pg->transaction_name = NULL;
+}
+
+
+enum GNUNET_DB_QueryStatus
+TMH_PG_commit (void *cls)
+{
+  struct PostgresClosure *pg = cls;
+  struct GNUNET_PQ_QueryParam params[] = {
+    GNUNET_PQ_query_param_end
+  };
+  enum GNUNET_DB_QueryStatus qs;
+
+  GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+              "Committing merchant DB transaction %s\n",
+              pg->transaction_name);
+  check_connection (pg);
+  PREPARE (pg,
+           "merchant_commit",
+           "COMMIT");
+  qs = GNUNET_PQ_eval_prepared_non_select (pg->conn,
+                                           "merchant_commit",
+                                           params);
+  if (qs < 0)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+                "Failed to commit transaction\n");
+    TMH_PG_rollback (pg);
+    return qs;
+  }
+  pg->transaction_name = NULL;
+  return qs;
+}