Trait exonum::storage::proof_map_index::HashedKey

pub trait HashedKey: CryptoHash { }

A trait denoting that a certain storage value is suitable for use as a key for ProofMapIndex after hashing.

Warning: The implementation of the ProofMapKey.write_key() method provided by this trait is not efficient; it calculates the hash anew on each call.

Example

#[derive(ProtobufConvert)]
#[exonum(pb = "exonum::proto::schema::doc_tests::Point")]
struct Point {
    x: i32,
    y: i32,
}

impl Point {
    fn new(x: i32, y: i32) -> Self {
        Self { x, y }
    }
}

impl HashedKey for Point {}

let mut fork = { let db = MemoryDB::new(); db.fork() };
let mut map = ProofMapIndex::new("index", &mut fork);
map.put(&Point::new(3, -4), 5u32);
assert_eq!(map.get(&Point::new(3, -4)), Some(5));
assert_eq!(map.get(&Point::new(3, 4)), None);

Implementors

Loading content...