On 2/7/2020 5:16 PM, Johannes Berg wrote: > The description of the multi-pack-index contains a small bug, > if all offsets are < 2^32 then there will be no LOFF chunk, > not only if they're all < 2^31 (since the highest bit is only > needed as the "LOFF-escape" when that's actually needed.) > > Correct this, and clarify that in that case only offsets up > to 2^31-1 can be stored in the OOFF chunk. > > Signed-off-by: Johannes Berg <johannes@xxxxxxxxxxxxxxxx> > --- > Documentation/technical/pack-format.txt | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/Documentation/technical/pack-format.txt b/Documentation/technical/pack-format.txt > index cab5bdd2ff0f..d3a142c65202 100644 > --- a/Documentation/technical/pack-format.txt > +++ b/Documentation/technical/pack-format.txt > @@ -315,10 +315,11 @@ CHUNK DATA: > Stores two 4-byte values for every object. > 1: The pack-int-id for the pack storing this object. > 2: The offset within the pack. > - If all offsets are less than 2^31, then the large offset chunk > + If all offsets are less than 2^32, then the large offset chunk > will not exist and offsets are stored as in IDX v1. > If there is at least one offset value larger than 2^32-1, then > - the large offset chunk must exist. If the large offset chunk > + the large offset chunk must exist, and offsets larger than > + 2^31-1 must be stored in it instead. If the large offset chunk > exists and the 31st bit is on, then removing that bit reveals > the row in the large offsets containing the 8-byte offset of > this object. Thank you for finding this doc bug. This is a very subtle point, and you have described it very clearly. -Stolee
