Module hash 

Content-addressing for the flat personality.

This is not a cryptographic hash

It is FNV-1a run four times under different seeds and concatenated. FNV is trivially collidable by construction — anyone who can choose two inputs can make them collide. A personality that accepts objects from an untrusted party must use a real cryptographic hash (JAVM uses BLAKE2 through javm-cap); using this one there would let an attacker substitute one program for another.

It is here because the flat personality’s job is to be the smallest complete example of the Personality/GuestPersonality pair, and to make nub’s own benchmarks runnable. In that setting there is no adversary, and a dependency-free 40-line hash keeps the example readable and keeps the guest build free of a crate that would want CPU feature detection on x86_64-unknown-none.

The one real constraint it must satisfy: host and guest compute the same value, since the host publishes by hash and invokes by hash. That is what the round-trip test pins.

Constants

ERROR_SENTINEL

The wire’s put-failure sentinel. GuestStore::put_object must never return this value for a real object; with four independent 64-bit lanes the odds of hitting all-ones are nil, but content_hash forces a bit clear rather than relying on that.

Functions

content_hash

Content-address bytes.

Type Aliases

Hash

32-byte object identity, matching nub_kernel::ObjHash’s shape.