Implement a StateReader that reads from a full-node about starknet_in_rust HOT 2 CLOSED

I am working on this for Juno.

I started writing Rust just yesterday, so this might be dumb. But I am wondering if it makes sense to constraint the trait to return &Felt.

Juno exports C symbols that Rust can call.

extern {
    fn JunoStateGetStorageAt(reader_handle: usize, contract_address: *const c_uchar,
                             storage_location: *const c_uchar) -> *const c_uchar;
}

and the reader implementation does some type conversions only and isn't stateful.

    fn get_storage_at(&mut self, storage_entry: &StorageEntry) -> Result<&Felt, StateError> {
        let addr = feltToJunoFelt(&storage_entry.0.0);
        let val = unsafe { JunoStateGetStorageAt(self.0, addr.as_ptr(), storage_entry.1.as_ptr()) };
        if val.is_null() {
            return Err(StateError::NoneContractState(storage_entry.0.clone()));
        }


        return Ok(&junoFeltToFelt(val))
    }

but since we are expected to return a borrowed value, we can't get away with just being a bridge and should have a storage of some sort to keep the Felts around. Even if it does have a storage, it wouldnt know when to clear a value from the storage, right?

My question is wouldn't returning a Felt here make more sense?

from starknet_in_rust.

#122

from starknet_in_rust.