.ls files are useful to seek in a NAR without parsing it entirely.
The responsibility of validating the files is on the caller.
Change-Id: I5d1da28b5479c38f20ca5babe60e362a2217c9ea
Signed-off-by: Ryan Lahfa <tvl@lahfa.xyz>
Reviewed-on: https://cl.tvl.fyi/c/depot/+/12196
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
Even if we have an aligned (or zero) size (and thus have no padding),
we may still have a non-padding trailer.
Since an exact read of only the user data bytes must always read the
trailer bytes as well, this has to happen for aligned sizes too.
For zero-sized trailers, we solve this by reading immediately, since no
read is required of the user at all.
user_len thus becomes a NonZeroU64, and the definition of "body data"
is adjusted to always exclude the final block.
Change-Id: I2c6bb51270fb22ad72a65076a3468673ab56ef68
Reviewed-on: https://cl.tvl.fyi/c/depot/+/11597
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
