On Wed, Mar 16, 2022 at 9:14 AM Junio C Hamano <gitster@xxxxxxxxx> wrote: > > Neeraj Singh <nksingh85@xxxxxxxxx> writes: > > > I think my new usage is congruent with the existing API, which seems > > to be about combining multiple add operations into a large transaction, > > where we can do some cleanup operations once we're finished. In the > > preexisting code, the transaction is about adding a bunch of large objects > > to a single pack file (while leaving small objects loose), and then completing > > the packfile when the adds are finished. > > OK, so it was part me, and part a suboptimal presentation, I guess > ;-) > > Let me rephrase the idea to see if I got it right this time. > > The bulk-checkin API has two interesting entry points, "plug" that > signals that we are about to repeat possibly many operations to add > new objects to the object store, and "unplug" that signals that we > are done such adding. They are meant to serve as a hint for the > object layer to optimize its operation. > > So far the only way the hint was used was that the logic that sends > an overly large object into a packfile (instead of storing it loose, > which leaves it subject to expensive repacking later) can shove more > than one such objects in the same packfile. > > This series invents another use of the "plug"-"unplug" hint. By > knowing that many loose object files are created and when the series > of object creation ended, we can avoid having to fsync each and > every one of them on certain filesystems and achieve the same > robustness. The new "batch" option to core.fsyncmethod triggers > this mechanism. > > Did I get it right, more-or-less? Yes, that's my understanding as well. Thanks, Neeraj
