Test if sqlite is multithreading-safe and bail out if not. sqlite
versions since at least 2008 are.
But, as it still causes errors when 2
threads try to write to the same connection simultanously (We get a
"cannot start transaction within a transaction" error), we protect
writes with a per class, ie per-connection lock. Factor out the retrying
to write when the database is locked.
Signed-off-by: Sebastian Spaeth <Sebastian@SSpaeth.de>
Signed-off-by: Nicolas Sebrecht <nicolas.s-dev@laposte.net>
doautosave was a useless variable before (it was *always* 1). So we
remove the self.dofsync variable and store in doautosave whether we
should fsync as often as possible (which really hurts performance).
The sqlite backend could (at one point) use the doautosave variable to
determine if it should autocommit after each modification.
Signed-off-by: Sebastian Spaeth <Sebastian@SSpaeth.de>
Signed-off-by: Nicolas Sebrecht <nicolas.s-dev@laposte.net>
Based on patches by Stewart Smith, updated by Rob Browning.
plus:
- Inherit LocalStatusSQLFolder from LocalStatusFolder
This lets us remove all functions that are available via our ancestors
classes and are not needed.
- Don't fail if pysql import fails. Fail rather at runtime when needed.
- When creating the db file, create a metadata table which contains the
format version info, so we can upgrade nicely to other formats.
- Create an upgrade_db() function which allows us to upgrade from any
previous file format to the current one (including plain text)
Signed-off-by: Sebastian Spaeth <Sebastian@SSpaeth.de>
Signed-off-by: Nicolas Sebrecht <nicolas.s-dev@laposte.net>
