unpack-objects: use the bulk-checkin infrastructure
The unpack-objects functionality is used by fetch, push, and fast-import to turn the transfered data into object database entries when there are fewer objects than the 'unpacklimit' setting. By enabling an odb-transaction when unpacking objects, we can take advantage of batched fsyncs. Here are some performance numbers to justify batch mode for unpack-objects, collected on a WSL2 Ubuntu VM. Fsync Mode | Time for 90 objects (ms) ------------------------------------- Off | 170 On,fsync | 760 On,batch | 230 Note that the default unpackLimit is 100 objects, so there's a 3x benefit in the worst case. The non-batch mode fsync scales linearly with the number of objects, so there are significant benefits even with smaller numbers of objects. Signed-off-by: Neeraj Singh <neerajsi@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>