path: root/pack-revindex.h
AgeCommit message (Collapse)Author
2019-04-16pack-revindex: open index if necessaryJeff King
We can't create a pack revindex if we haven't actually looked at the index. Normally we would never get as far as creating a revindex without having already been looking in the pack, so this code never bothered to double-check that pack->index_data had been loaded. But with the new multi-pack-index feature, many code paths might not load the individual pack .idx at all (they'd find objects via the midx and then open the .pack, but not its index). This can't yet be triggered in practice, because a bug in the midx code means we accidentally open up the individual .idx files anyway. But in preparation for fixing that, let's have the revindex code check that everything it needs has been loaded. In most cases this will just be a quick noop. But note that this does introduce a possibility of error (if we have to open the index and it's corrupt), so load_pack_revindex() now returns a result code, and callers need to handle the error. Signed-off-by: Jeff King <> Signed-off-by: Junio C Hamano <>
2015-12-21pack-revindex: store entries directly in packed_gitJeff King
A pack_revindex struct has two elements: the revindex entries themselves, and a pointer to the packed_git. We need both to do lookups, because only the latter knows things like the number of objects in the pack. Now that packed_git contains the pack_revindex struct it's just as easy to pass around the packed_git itself, and we do not need the extra back-pointer. We can instead just store the entries directly in the pack. All functions which took a pack_revindex now just take a packed_git. We still lazy-load in find_pack_revindex, so most callers are unaffected. The exception is the bitmap code, which computes the revindex and caches the pointer when we load the bitmaps. We can continue to load, drop the extra cache pointer, and just access bitmap_git.pack.revindex directly. Signed-off-by: Jeff King <> Signed-off-by: Junio C Hamano <>
2014-01-16do not discard revindex when re-preparing packfilesJeff King
When an object lookup fails, we re-read the objects/pack directory to pick up any new packfiles that may have been created since our last read. We also discard any pack revindex structs we've allocated. The discarding is a problem for the pack-bitmap code, which keeps a pointer to the revindex for the bitmapped pack. After the discard, the pointer is invalid, and we may read free()d memory. Other revindex users do not keep a bare pointer to the revindex; instead, they always access it through revindex_for_pack(), which lazily builds the revindex. So one solution is to teach the pack-bitmap code a similar trick. It would be slightly less efficient, but probably not all that noticeable. However, it turns out this discarding is not actually necessary. When we call reprepare_packed_git, we do not throw away our old pack list. We keep the existing entries, and only add in new ones. So there is no safety problem; we will still have the pack struct that matches each revindex. The packfile itself may go away, of course, but we are already prepared to handle that, and it may happen outside of reprepare_packed_git anyway. Throwing away the revindex may save some RAM if the pack never gets reused (about 12 bytes per object). But it also wastes some CPU time (to regenerate the index) if the pack does get reused. It's hard to say which is more valuable, but in either case, it happens very rarely (only when we race with a simultaneous repack). Just leaving the revindex in place is simple and safe both for current and future code. Signed-off-by: Jeff King <> Signed-off-by: Junio C Hamano <>
2013-10-24revindex: export new APIsVicent Marti
Allow users to efficiently lookup consecutive entries that are expected to be found on the same revindex by exporting `find_revindex_position`: this function takes a pointer to revindex itself, instead of looking up the proper revindex for a given packfile on each call. Signed-off-by: Vicent Marti <> Signed-off-by: Jeff King <> Signed-off-by: Junio C Hamano <>
2008-08-23discard revindex data when pack list changesNicolas Pitre
This is needed to fix verify-pack -v with multiple pack arguments. Also, in theory, revindex data (if any) must be discarded whenever reprepare_packed_git() is called. In practice this is hard to trigger though. Signed-off-by: Nicolas Pitre <> Signed-off-by: Junio C Hamano <>
2008-06-24call init_pack_revindex() lazilyNicolas Pitre
This makes life much easier for next patch, as well as being more efficient when the revindex is actually not used. Signed-off-by: Nicolas Pitre <> Signed-off-by: Junio C Hamano <>
2008-03-01factorize revindex code out of builtin-pack-objects.cNicolas Pitre
No functional change. This is needed to fix verify-pack in a later patch. Signed-off-by: Nicolas Pitre <> Signed-off-by: Junio C Hamano <>