There is FxHashMap (https://github.com/rust-lang/rustc-hash) which is faster than std::collections::HashMap.
With ~100 static entries, o1hash (https://github.com/rurban/smhasher/blob/master/o1hash.h) should also work.
With ~100 static entries, o1hash (https://github.com/rurban/smhasher/blob/master/o1hash.h) should also work.