Struct patricia_trie::triedb::TrieDB

pub struct TrieDB<'db> {
    pub hash_count: usize,
    // some fields omitted
}

A Trie implementation using a generic HashDB backing database.

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 patricia_trie as trie;
extern crate hashdb;
extern crate memorydb;
extern crate ethcore_bigint as bigint;

use trie::*;
use hashdb::*;
use memorydb::*;
use bigint::hash::*;

fn main() {
  let mut memdb = MemoryDB::new();
  let mut root = H256::new();
  TrieDBMut::new(&mut memdb, &mut root).insert(b"foo", b"bar").unwrap();
  let t = TrieDB::new(&memdb, &root).unwrap();
  assert!(t.contains(b"foo").unwrap());
  assert_eq!(t.get(b"foo").unwrap().unwrap(), DBValue::from_slice(b"bar"));
}

Fields

hash_count: usize

The number of hashes performed so far in operations on this trie.

Methods

impl<'db> TrieDB<'db>

fn new(db: &'db HashDB, root: &'db H256) -> Result<Self>

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

fn db(&'db self) -> &'db HashDB

Get the backing database.

Trait Implementations

impl<'db> Trie for TrieDB<'db>

fn iter<'a>(&'a self) -> Result<Box<TrieIterator<Item = TrieItem> + 'a>>

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

fn root(&self) -> &H256

Return the root of the trie.

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

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

fn is_empty(&self) -> bool

Is the trie empty?

fn contains(&self, key: &[u8]) -> Result<bool>

Does the trie contain a given key?

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

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

impl<'db> Debug for TrieDB<'db>

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

Formats the value using the given formatter.