Python sqlalchemy.exc 模块，DisconnectionError() 实例源码

def ping_listener(dbapi_conn, connection_rec, connection_proxy):
    """
    Ensures that MySQL connections checked out of the
    pool are alive.

    Borrowed from:
    http://groups.google.com/group/sqlalchemy/msg/a4ce563d802c929f
    """
    try:
        dbapi_conn.cursor().execute('select 1')
    except dbapi_conn.OperationalError, ex:
        if ex.args[0] in (2006, 2013, 2014, 2045, 2055):
            LOG.warn('Got mysql server has gone away: %s', ex)
            raise DisconnectionError("Database server went away")
        else:
            raise

def mysql_ping_listener(dbapi_conn, connection_rec, connection_proxy):
    """
    Ensures that MySQL connections checked out of the
    pool are alive.

    Borrowed from:
    http://groups.google.com/group/sqlalchemy/msg/a4ce563d802c929f

    :param dbapi_conn: DBAPI connection
    :param connection_rec: connection record
    :param connection_proxy: connection proxy
    """

    try:
        dbapi_conn.cursor().execute('select 1')
    except dbapi_conn.OperationalError, ex:
        if ex.args[0] in (2006, 2013, 2014, 2045, 2055):
            msg = 'Got mysql server has gone away: %s' % ex
            raise DisconnectionError(msg)
        else:
            raise

def ping_connection(dbapi_connection, connection_record, connection_proxy):
    cursor = dbapi_connection.cursor()
    try:
        cursor.execute("SELECT 1")
    except:
        # optional - dispose the whole pool
        # instead of invalidating one at a time
        # connection_proxy._pool.dispose()

        # raise DisconnectionError - pool will try
        # connecting again up to three times before raising.
        raise exc.DisconnectionError()
    cursor.close()

# Define Bucket Items

def checkout_listener(dbapi_con, con_record, con_proxy):
    try:
        try:
            dbapi_con.ping(False)
        except TypeError:
            dbapi_con.ping()
    except dbapi_con.OperationalError as exc:
        if exc.args[0] in (2006, 2013, 2014, 2045, 2055):
            raise DisconnectionError()
        else:
            raise

def checkout_listener(dbapi_con, con_record, con_proxy):
    try:
        try:
            dbapi_con.ping(False)
        except TypeError:
            dbapi_con.ping()
    except dbapi_con.OperationalError as exc:
        if exc.args[0] in (2006, 2013, 2014, 2045, 2055):
            raise DisconnectionError()
        else:
            raise

def checkout(self, dbapi_con, con_record, con_proxy):
        try:
            dbapi_con.cursor().execute('select 1')
        except dbapi_con.OperationalError, ex:
            if ex.args[0] in (2006, 2013, 2014, 2045, 2055):
                LOG.warn('Got mysql server has gone away: %s', ex)
                raise DisconnectionError("Database server went away")
            else:
                raise

def _checkout_listener(self, dbapi_con, con_record, con_proxy):
        try:
            try:
                dbapi_con.ping(False)
            except TypeError:
                dbapi_con.ping()
        except dbapi_con.OperationalError as exc:
            if exc.args[0] in (2006, 2013, 2014, 2045, 2055):
                raise DisconnectionError()
            else:
                raise

def pessimistic_connection_handling():
    @event.listens_for(Pool, "checkout")
    def ping_connection(dbapi_connection, connection_record, connection_proxy):
        '''
        Disconnect Handling - Pessimistic, taken from:
        http://docs.sqlalchemy.org/en/rel_0_9/core/pooling.html
        '''
        cursor = dbapi_connection.cursor()
        try:
            cursor.execute("SELECT 1")
        except:
            raise exc.DisconnectionError()
        cursor.close()

def checkout(dbapi_connection, connection_record, connection_proxy):
    pid = os.getpid()
    if connection_record.info['pid'] != pid:
        connection_record.connection = connection_proxy.connection = None
        raise exc.DisconnectionError(
            "Connection record belongs to pid {}, "
            "attempting to check out in pid {}".format(connection_record.info['pid'], pid)
        )

def checkout(dbapi_connection, connection_record, connection_proxy):
    pid = os.getpid()
    if connection_record.info['pid'] != pid:
        connection_record.connection = connection_proxy.connection = None
        raise exc.DisconnectionError("Connection record belongs to pid %s, "
                                     "attempting to check out in pid %s" %
                                     (connection_record.info['pid'], pid))