Struct trie_db::triedb::TrieDB

pub struct TrieDB<'db, H, C> where
    H: Hasher + 'db,
    C: NodeCodec<H>,  { /* 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

extern crate trie_db;
extern crate reference_trie;
extern crate hash_db;
extern crate keccak_hasher;
extern crate memory_db;

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

fn main() {
  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(), DBValue::from_slice(b"bar"));
}

Methods

impl<'db, H, C> TrieDB<'db, H, C> where
    H: Hasher,
    C: NodeCodec<H>, 

pub fn new(
    db: &'db dyn HashDBRef<H, DBValue>,
    root: &'db H::Out
) -> Result<Self, H::Out, C::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<H, DBValue>

Get the backing database.

pub fn root_data(&self) -> Result<DBValue, H::Out, C::Error>

Get the data of the root node.

Trait Implementations

impl<'db, H, C> Trie<H, C> for TrieDB<'db, H, C> where
    H: Hasher,
    C: NodeCodec<H>, 

fn root(&self) -> &H::Out

Return the root of the trie.

fn get_with<'a, 'key, Q: Query<H>>(
    &'a self,
    key: &'key [u8],
    query: Q
) -> Result<Option<Q::Item>, H::Out, C::Error> where
    'a: 'key, 

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

fn iter<'a>(
    &'a self
) -> Result<Box<dyn TrieIterator<H, C, Item = TrieItem<H::Out, C::Error>> + 'a>, H::Out, C::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, H::Out, C::Error>

Does the trie contain a given key?

fn get<'a, 'key>(
    &'a self,
    key: &'key [u8]
) -> Result<Option<DBValue>, H::Out, C::Error> where
    'a: 'key, 

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

impl<'db, H, C> Debug for TrieDB<'db, H, C> where
    H: Hasher,
    C: NodeCodec<H>, 

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

Formats the value using the given formatter.