Hi Jelmer, On Sun, Sep 19, 2010 at 10:16:18AM -0700, Jelmer Vernooij wrote: > Hi Kirill, > > On Sun, 2010-09-19 at 13:53 +0400, Kirill Smelkov wrote: > > Rusty, Jelmer, > > > > The subject says it all. Not 100% complete, but near. > Thanks for the patches. I've applied most of the Python ones. I'm not at > all convinced we should match the C API in the Python API though, I > rather think we should let the needs of our Python users drive what we > expose. Some of the worst Python bindings I've seen were created by > simply mapping every C function one on one to Python. > > Is there any particular reason why some of these functions should be > exposed? Why do you need low-level locking?
Thanks for applying some patches and sorry I've not described my context initially... In this case I myself is tdb python user - I use tdb in embedded system for internal database to which many programms "connect" simultaneously to read/write it. That's why I need locking, and better, to avoid lock contention, the chainlock_* family variants. Also, sometimes it is not important to write data to db immediately, so to minize latencies, apps keep to-be-written queue internally until they know they can write to some chain, or start transaction - that's why I need *_nonblock variants. Same for reading - once initially read, it's not that important to get up-to-date values immediately, that's why I'd also use tdb_chainlock_read_nonblock(). And to make life a bit more interesting, db is stored on compact flash -- various types, from various vendors, so with various types of flash translation layers (FTL) -- so inevitably with bugs in FTL with respect to sudden power failures, so I'm preparing to have corrupt tdb one day http://ozlabs.org/~rusty/index.cgi/tech/2009-10-20.html http://lwn.net/Articles/349970/ That's why I'd also like to have debugging routines (dump_all, print_freelist, etc..,), and tdb_check (not yet done, should I?), and also tdb_fd and tdb_repack come for completness (doesn't tdb_repack complement tdb_wipe_all() which has python bindings?). And we don't have shutdown sequence - normal shutdown is poweroff... Hope this clarifies my rationale about why we should expose more functionality in pytdb. Thanks, Kirill On Sun, Sep 19, 2010 at 09:29:19AM -0700, Jelmer Vernooij wrote: > Hi Kirill, > > On Sun, 2010-09-19 at 13:53 +0400, Kirill Smelkov wrote: > > Though when doing `make check-python` the dump is intermixed into > > testing output :( > I'm not convinced exposing these methods in the Python API is all that > useful. They're mainly useful for debugging tdb itself. Is there > anything in particular you'd like to use them for? See above about corrupt tdbs and debugging. -- To UNSUBSCRIBE, email to [email protected] with a subject of "unsubscribe". Trouble? Contact [email protected]
