[PATCH RESEND v3 1/2] daemon: telegram: db: Allow the caller to reconnect

[Ammar Faizi <ammarfaizi2@gnuweeb.org>]

The daemon is totally unusable when the MySQL server is restarted. It's
spinning in a loop with the following error:

   mysql.connector.errors.OperationalError: 2013 (HY000): Lost connection to MySQL server during query

When it happens, the only way to fix the situation is: restart the
daemon manually, which is obviously not productive. Create a mechanism
in the class DB to allow the caller to reconnect. This way, the caller
can automatically reconnect without having the user restart the daemon.

v2:
  - Use conn.ping(reconnect=True) instead of creating a new MySQL
    connection object (comment from Muhammad Rizki).

Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
---
 daemon/telegram/database/core.py | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/daemon/telegram/database/core.py b/daemon/telegram/database/core.py
index c34d7a8..26f671b 100644
--- a/daemon/telegram/database/core.py
+++ b/daemon/telegram/database/core.py
@@ -14,6 +14,11 @@ class DB(DBMethods):
 		self.conn.autocommit = True
 		self.cur = self.conn.cursor(buffered=True)
 
+	def ping(self, reconnect=True, attempts=3, delay=3):
+		self.conn.ping(reconnect=reconnect, attempts=attempts,
+				delay=delay)
+		self.cur = self.conn.cursor(buffered=True)
+
 
 	def __del__(self):
 		self.cur.close()
-- 
Ammar Faizi