Struct reference_trie::TrieDB

pub struct TrieDB<'db, L> where
    L: TrieLayout,  { /* fields omitted */ }

A Trie implementation using a generic HashDB backing database, a Hasher implementation to generate keys and a NodeCodec implementation to encode/decode the nodes.

Use it as a Trie trait object. You can use db() to get the backing database object. Use get and contains to query values associated with keys in the trie.

Example

use hash_db::Hasher;
use reference_trie::{RefTrieDBMut, RefTrieDB, Trie, TrieMut};
use trie_db::DBValue;
use keccak_hasher::KeccakHasher;
use memory_db::*;

let mut memdb = MemoryDB::<KeccakHasher, HashKey<_>, _>::default();
let mut root = Default::default();
RefTrieDBMut::new(&mut memdb, &mut root).insert(b"foo", b"bar").unwrap();
let t = RefTrieDB::new(&memdb, &root).unwrap();
assert!(t.contains(b"foo").unwrap());
assert_eq!(t.get(b"foo").unwrap().unwrap(), b"bar".to_vec());

Methods

impl<'db, L> TrieDB<'db, L> where
    L: TrieLayout, 

pub fn new(
    db: &'db (dyn HashDBRef<<L as TrieLayout>::Hash, Vec<u8>> + 'db),
    root: &'db <<L as TrieLayout>::Hash as Hasher>::Out
) -> Result<TrieDB<'db, L>, Box<TrieError<<<L as TrieLayout>::Hash as Hasher>::Out, <<L as TrieLayout>::Codec as NodeCodec>::Error>>>

Create a new trie with the backing database db and root Returns an error if root does not exist

pub fn db(
    &'db self
) -> &'db (dyn HashDBRef<<L as TrieLayout>::Hash, Vec<u8>> + 'db)

Get the backing database.

Trait Implementations

impl<'db, L> Debug for TrieDB<'db, L> where
    L: TrieLayout, 

fn fmt(&self, f: &mut Formatter) -> Result<(), Error>

Formats the value using the given formatter.

impl<'db, L> Trie<L> for TrieDB<'db, L> where
    L: TrieLayout, 

fn root(&self) -> &<<L as TrieLayout>::Hash as Hasher>::Out

Return the root of the trie.

fn get_with<'a, 'key, Q>(
    &'a self,
    key: &'key [u8],
    query: Q
) -> Result<Option<<Q as Query<<L as TrieLayout>::Hash>>::Item>, Box<TrieError<<<L as TrieLayout>::Hash as Hasher>::Out, <<L as TrieLayout>::Codec as NodeCodec>::Error>>> where
    'a: 'key,
    Q: Query<<L as TrieLayout>::Hash>, 

Search for the key with the given query parameter. See the docs of the Query trait for more details.

fn iter(
    &'a self
) -> Result<Box<dyn TrieIterator<L, Item = Result<(Vec<u8>, Vec<u8>), Box<TrieError<<<L as TrieLayout>::Hash as Hasher>::Out, <<L as TrieLayout>::Codec as NodeCodec>::Error>>>> + 'a>, Box<TrieError<<<L as TrieLayout>::Hash as Hasher>::Out, <<L as TrieLayout>::Codec as NodeCodec>::Error>>>

Returns a depth-first iterator over the elements of trie.

fn is_empty(&self) -> bool

Is the trie empty?

fn contains(
    &self,
    key: &[u8]
) -> Result<bool, Box<TrieError<<<L as TrieLayout>::Hash as Hasher>::Out, <<L as TrieLayout>::Codec as NodeCodec>::Error>>>

Does the trie contain a given key?

fn get<'a, 'key>(
    &'a self,
    key: &'key [u8]
) -> Result<Option<Vec<u8>>, Box<TrieError<<<L as TrieLayout>::Hash as Hasher>::Out, <<L as TrieLayout>::Codec as NodeCodec>::Error>>> where
    'a: 'key, 

What is the value of the given key in this trie?