From 4ad39b6b73a9dd2716855e08c67a905d02a1cf97 Mon Sep 17 00:00:00 2001
From: Christian Grothoff <christian@grothoff.org>
Date: Sun, 21 Oct 2018 20:52:26 +0200
Subject: first skeleton of /deposit-confirmation API implementation; not yet
 complete, cannot work as-is, see FIXMEs

---
 src/auditor/taler-auditor-httpd_db.c | 120 +++++++++++++++++++++++++++++++++++
 1 file changed, 120 insertions(+)
 create mode 100644 src/auditor/taler-auditor-httpd_db.c

(limited to 'src/auditor/taler-auditor-httpd_db.c')

diff --git a/src/auditor/taler-auditor-httpd_db.c b/src/auditor/taler-auditor-httpd_db.c
new file mode 100644
index 000000000..846829551
--- /dev/null
+++ b/src/auditor/taler-auditor-httpd_db.c
@@ -0,0 +1,120 @@
+/*
+  This file is part of TALER
+  Copyright (C) 2014-2018 GNUnet e.V.
+
+  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 taler-auditor-httpd_db.c
+ * @brief Generic database operations for the auditor.
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include <pthread.h>
+#include <jansson.h>
+#include <gnunet/gnunet_json_lib.h>
+#include "taler_json_lib.h"
+#include "taler-auditor-httpd_db.h"
+#include "taler-auditor-httpd_responses.h"
+
+
+/**
+ * How often should we retry a transaction before giving up
+ * (for transactions resulting in serialization/dead locks only).
+ */
+#define MAX_TRANSACTION_COMMIT_RETRIES 100
+
+
+/**
+ * Run a database transaction for @a connection.
+ * Starts a transaction and calls @a cb.  Upon success,
+ * attempts to commit the transaction.  Upon soft failures,
+ * retries @a cb a few times.  Upon hard or persistent soft
+ * errors, generates an error message for @a connection.
+ *
+ * @param connection MHD connection to run @a cb for
+ * @param name name of the transaction (for debugging)
+ * @param[out] set to MHD response code, if transaction failed
+ * @param cb callback implementing transaction logic
+ * @param cb_cls closure for @a cb, must be read-only!
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR on failure
+ */
+int
+TAH_DB_run_transaction (struct MHD_Connection *connection,
+                        const char *name,
+			int *mhd_ret,
+			TAH_DB_TransactionCallback cb,
+			void *cb_cls)
+{
+  struct TALER_AUDITORDB_Session *session;
+
+  if (NULL != mhd_ret)
+    *mhd_ret = -1; /* invalid value */
+  if (NULL == (session = TAH_plugin->get_session (TAH_plugin->cls)))
+  {
+    GNUNET_break (0);
+    if (NULL != mhd_ret)
+      *mhd_ret = TAH_RESPONSE_reply_internal_db_error (connection,
+						       TALER_EC_DB_SETUP_FAILED);
+    return GNUNET_SYSERR;
+  }
+  //  TAH_plugin->preflight (TAH_plugin->cls, session); // FIXME: needed?
+  for (unsigned int retries = 0;retries < MAX_TRANSACTION_COMMIT_RETRIES; retries++)
+  {
+    enum GNUNET_DB_QueryStatus qs;
+
+    if (GNUNET_OK !=
+	TAH_plugin->start (TAH_plugin->cls,
+			   session))
+    {
+      GNUNET_break (0);
+      if (NULL != mhd_ret)
+	*mhd_ret = TAH_RESPONSE_reply_internal_db_error (connection,
+							 TALER_EC_DB_START_FAILED);
+      return GNUNET_SYSERR;
+    }
+    qs = cb (cb_cls,
+	     connection,
+	     session,
+	     mhd_ret);
+    if (0 > qs)
+      TAH_plugin->rollback (TAH_plugin->cls,
+			    session);
+    if (GNUNET_DB_STATUS_HARD_ERROR == qs)
+      return GNUNET_SYSERR;
+    if (0 <= qs)
+      qs = TAH_plugin->commit (TAH_plugin->cls,
+			       session);
+    if (GNUNET_DB_STATUS_HARD_ERROR == qs)
+    {
+      if (NULL != mhd_ret)
+	*mhd_ret = TAH_RESPONSE_reply_commit_error (connection,
+						    TALER_EC_DB_COMMIT_FAILED_HARD);
+      return GNUNET_SYSERR;
+    }
+    /* make sure callback did not violate invariants! */
+    GNUNET_assert ( (NULL == mhd_ret) ||
+		    (-1 == *mhd_ret) );
+    if (0 <= qs)
+      return GNUNET_OK;
+  }
+  TALER_LOG_ERROR ("Transaction `%s' commit failed %u times\n",
+                   name,
+                   MAX_TRANSACTION_COMMIT_RETRIES);
+  if (NULL != mhd_ret)
+    *mhd_ret = TAH_RESPONSE_reply_commit_error (connection,
+						TALER_EC_DB_COMMIT_FAILED_ON_RETRY);
+  return GNUNET_SYSERR;
+}
+
+
+/* end of taler-auditor-httpd_db.c */
-- 
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