get next binlog pos in OnRow eventhandler

[ideamean]

will you add a field of the next binlog pos to canal.RowsEvent?
In "canal.EventHandler.OnRow(e *RowsEvent) error" function, I want to save the next positon. if my process crash and restart, I will read the last position?

[siddontang]

hi @ideamean

The Header.LogPos in the RowsEvent is already the next position.

[ideamean]

but not in canal.RowsEvent, I think if add a parameter here?

[siddontang]

Got it, but why not handle OnPosSynced, it will be caused at the end of every transaction.

I think saving pos in txn in Rows does nothing.

[ideamean]

In OnRow function, I get the new data then push data to another store (eg. kafaka, redis), if push success, I will save the next pos.
if use OnPosSynced, I don't konw the last successed position.
would you give me a better way?

[ideamean]

another way, you can pass one more parameter of the current binlog data size(DataSize), I use Canal.SyncedPosition() + DataSize?

func (c *Canal) SyncedPosition() mysql.Position {
	return c.master.Position()
}

[siddontang]

If you really want to use it, you can add a NextPos field in RowsEvent. @ideamean

You can send me a PR.