See also #27675
`Allocator.Alloc` and `Allocator.AllocOne` might be invoked multiple
times if there were multiple blobs set in one sync task.
This PR add pre-fetch logic for all blobs and cache logIDs in sync task
so that at most only one call of the allocator is needed.
---------
Signed-off-by: Congqi Xia <congqi.xia@zilliz.com>