I don't see how the callbacks are useful though. Vacuum works
transparently, its effects are not visible, and what should the page do
in
case of error ?
i was thinking of something like:
db.defragment(errorCallback, successCallback);
showAPrettyImageAndAskTheUserToWait();
function errorCallback(error) {}
function successCallback() {
getRidOfThePrettyImageAndRestartTheApp();
}
just like you, i'm not sure if the error callback is useful at all, but i
thought i'd add it to make the defragment() call look more like a
transaction. maybe we don't need it.
True, but this is a kind of operation that could very well just run on the
background, with a single optional callback when it's done (the webpage
can't do anything if an error is detected anyway). The user agent would
need to queue any subsequent transactions if a vacuum is running. I would
consider it as an hint, and after all webpages that own references to the
underlying data files are closed, would do a vacuum. So, if you have many
tabs on gmail, and that a single gmail instance tries to do multiple
vacuums, it would equiv to one single vacuum operation.
Sqlite supports incremental vacuum http://www.sqlite.org/pragma.html so
this kind of feature should be left for sqlite to handle for itself.
in addition to what jeremy said, having auto-vacuum on is going to add
some
performance overhead to every transaction. this is not acceptable to some
apps.
I perused through the docs, and unfortunately auto-vaccum seems not like
the ideal solution.
--
João Eiras
Core Developer, Opera Software ASA, http://www.opera.com/
