db_mysql.py

import sys
import MySQLdb
from db_sql import DBSQL

class DBMySQL(DBSQL):

	# The Context class allows using context capsules for the sql transactions
	# Note: this behaviour has disappeared from MySQLdb as of 2018
	class Context:
		def __init__ (self, db, conn):
			self.DB = db
			self.Conn = conn
			self.Conn.ping(True)
			self.Conn.autocommit = False

		def __enter__(self):
			pass

		def __exit__ (self, type, value, traceback):
			if type is None:
				self.Conn.commit ()
			else:
				if self.DB.Verbose:
					sys.stdout.flush ()
					sys.stdout.write ("[SQL] Warning: db context exited with an exception, rollback!\n")
					sys.stdout.flush ()
				self.Conn.rollback ()

		def cursor (self):
			return self.Conn.cursor ()


	def __init__ (self, host, user, password, database, **kwargs):
		self.config = kwargs["config"]
		self.cloudconfig = kwargs["cloudconfig"]
		self.Conn = self.Context (self, MySQLdb.connect(host, user, password, database))
		# super is called *after* because DBSQL inits stuffs in the DB
		super(DBMySQL, self).__init__()