On 04/24/2015 07:30 PM, Jeff King wrote: > On Fri, Apr 24, 2015 at 01:35:48PM +0200, Michael Haggerty wrote: > >> Instead, work directly with update->flags. This has the advantage that >> the REF_DELETING bit, set in the first loop, can be read in the third >> loop instead of having to compute the same expression again. Plus, it >> was kindof confusing having both update->flags and flags, which >> sometimes had different values. > > Hmm. I think this is losing the distinction of "flags the caller has > passed in to us" versus "flags we are using locally only during the > transaction_commit routine". If callers look at the flags in the > REF_TRANSACTION_CLOSED state, do they care about seeing these new flags? > > My guess is probably not in practice, and "leaking" these flags is an > acceptable tradeoff for keeping the transaction_commit function simpler. > But I haven't looked that closely.
"struct ref_update" is opaque to callers outside of the refs module, and ref_update::flags is not read anywhere outside of ref_transaction_commit() (and its value is passed to lock_ref_sha1_basic()). So I don't think we have to be shy about storing our own internal information there. In fact, REF_DELETING, REF_ISPRUNING, REF_HAVE_NEW, and REF_HAVE_OLD are also private to the refs module. I suppose we could mask out all the "private" bits in the flags parameter passed by the caller, to make sure that the caller hasn't accidentally set other bits. I think that would be more defensive than our usual practice, but I don't mind doing it if people think it would be prudent. Michael -- Michael Haggerty mhag...@alum.mit.edu -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
