123 lines
3.4 KiB
Rust
123 lines
3.4 KiB
Rust
|
// Copyright 2015, 2016 Ethcore (UK) Ltd.
|
||
|
|
// This file is part of Parity.
|
||
|
|
|
||
|
|
// Parity is free software: you can redistribute it and/or modify
|
||
|
|
// it under the terms of the GNU General Public License as published by
|
||
|
|
// the Free Software Foundation, either version 3 of the License, or
|
||
|
|
// (at your option) any later version.
|
||
|
|
|
||
|
|
// Parity is distributed in the hope that it will be useful,
|
||
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
|
|
// GNU General Public License for more details.
|
||
|
|
|
||
|
|
// You should have received a copy of the GNU General Public License
|
||
|
|
// along with Parity. If not, see <http://www.gnu.org/licenses/>.
|
||
|
|
|
||
|
|
use hash::H256;
|
||
|
|
use sha3::Hashable;
|
||
|
|
use hashdb::HashDB;
|
||
|
|
use super::{TrieDBMut, Trie, TrieDB, TrieMut, TrieDBIterator, TrieError};
|
||
|
|
|
||
|
|
/// A mutable `Trie` implementation which hashes keys and uses a generic `HashDB` backing database.
|
||
|
|
///
|
||
|
|
/// Use it as a `Trie` or `TrieMut` trait object. You can use `raw()` to get the backing `TrieDBMut` object.
|
||
|
|
pub struct FatDB<'db> {
|
||
|
|
raw: TrieDBMut<'db>,
|
||
|
|
}
|
||
|
|
|
||
|
|
impl<'db> FatDB<'db> {
|
||
|
|
/// Create a new trie with the backing database `db` and empty `root`
|
||
|
|
/// Initialise to the state entailed by the genesis block.
|
||
|
|
/// This guarantees the trie is built correctly.
|
||
|
|
pub fn new(db: &'db mut HashDB, root: &'db mut H256) -> Self {
|
||
|
|
FatDB { raw: TrieDBMut::new(db, root) }
|
||
|
|
}
|
||
|
|
|
||
|
|
/// Create a new trie with the backing database `db` and `root`.
|
||
|
|
///
|
||
|
|
/// Returns an error if root does not exist.
|
||
|
|
pub fn from_existing(db: &'db mut HashDB, root: &'db mut H256) -> Result<Self, TrieError> {
|
||
|
|
Ok(FatDB { raw: try!(TrieDBMut::from_existing(db, root)) })
|
||
|
|
}
|
||
|
|
|
||
|
|
/// Get the backing database.
|
||
|
|
pub fn db(&self) -> &HashDB {
|
||
|
|
self.raw.db()
|
||
|
|
}
|
||
|
|
|
||
|
|
/// Get the backing database.
|
||
|
|
pub fn db_mut(&mut self) -> &mut HashDB {
|
||
|
|
self.raw.db_mut()
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
impl<'db> Trie for FatDB<'db> {
|
||
|
|
fn root(&self) -> &H256 {
|
||
|
|
self.raw.root()
|
||
|
|
}
|
||
|
|
|
||
|
|
fn contains(&self, key: &[u8]) -> bool {
|
||
|
|
self.raw.contains(&key.sha3())
|
||
|
|
}
|
||
|
|
|
||
|
|
fn get<'a, 'key>(&'a self, key: &'key [u8]) -> Option<&'a [u8]> where 'a: 'key {
|
||
|
|
self.raw.get(&key.sha3())
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
impl<'db> TrieMut for FatDB<'db> {
|
||
|
|
fn insert(&mut self, key: &[u8], value: &[u8]) {
|
||
|
|
let hash = key.sha3();
|
||
|
|
self.raw.insert(&hash, value);
|
||
|
|
let db = self.raw.db_mut();
|
||
|
|
db.insert_aux(hash.to_vec(), key.to_vec());
|
||
|
|
}
|
||
|
|
|
||
|
|
fn remove(&mut self, key: &[u8]) {
|
||
|
|
self.raw.remove(&key.sha3());
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/// Itarator over inserted pairs of key values.
|
||
|
|
pub struct FatDBIterator<'db> {
|
||
|
|
trie_iterator: TrieDBIterator<'db>,
|
||
|
|
trie: &'db TrieDB<'db>,
|
||
|
|
}
|
||
|
|
|
||
|
|
impl<'db> FatDBIterator<'db> {
|
||
|
|
pub fn new(trie: &'db TrieDB) -> Self {
|
||
|
|
FatDBIterator {
|
||
|
|
trie_iterator: TrieDBIterator::new(trie),
|
||
|
|
trie: trie,
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
impl<'db> Iterator for FatDBIterator<'db> {
|
||
|
|
type Item = (Vec<u8>, &'db [u8]);
|
||
|
|
|
||
|
|
fn next(&mut self) -> Option<Self::Item> {
|
||
|
|
self.trie_iterator.next()
|
||
|
|
.map(|(hash, value)| {
|
||
|
|
(self.trie.db().get_aux(&hash).expect("Missing fatdb hash"), value)
|
||
|
|
})
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
#[test]
|
||
|
|
fn fatdb_to_trie() {
|
||
|
|
use memorydb::MemoryDB;
|
||
|
|
use super::TrieDB;
|
||
|
|
|
||
|
|
let mut memdb = MemoryDB::new();
|
||
|
|
let mut root = H256::default();
|
||
|
|
{
|
||
|
|
let mut t = FatDB::new(&mut memdb, &mut root);
|
||
|
|
t.insert(&[0x01u8, 0x23], &[0x01u8, 0x23]);
|
||
|
|
}
|
||
|
|
let t = TrieDB::new(&memdb, &root).unwrap();
|
||
|
|
assert_eq!(t.get(&(&[0x01u8, 0x23]).sha3()).unwrap(), &[0x01u8, 0x23]);
|
||
|
|
assert_eq!(FatDBIterator::new(&t).collect::<Vec<_>>(), vec![(vec![0x01u8, 0x23], &[0x01u8, 0x23] as &[u8])]);
|
||
|
|
}
|