// Copyright 2015-2018 Parity Technologies (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 .
use hashdb::{HashDB, Hasher};
use super::{Result, TrieDB, Trie, TrieDBIterator, TrieItem, TrieIterator, Query};
use node_codec::NodeCodec;
/// A `Trie` implementation which hashes keys and uses a generic `HashDB` backing database.
/// Additionaly it stores inserted hash-key mappings for later retrieval.
///
/// Use it as a `Trie` or `TrieMut` trait object.
pub struct FatDB<'db, H, C>
where
H: Hasher + 'db,
C: NodeCodec
{
raw: TrieDB<'db, H, C>,
}
impl<'db, H, C> FatDB<'db, H, C>
where
H: Hasher,
C: NodeCodec
{
/// 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 HashDB, root: &'db H::Out) -> Result {
Ok(FatDB { raw: TrieDB::new(db, root)? })
}
/// Get the backing database.
pub fn db(&self) -> &HashDB { self.raw.db() }
}
impl<'db, H, C> Trie for FatDB<'db, H, C>
where
H: Hasher,
C: NodeCodec
{
fn root(&self) -> &H::Out { self.raw.root() }
fn contains(&self, key: &[u8]) -> Result {
self.raw.contains(H::hash(key).as_ref())
}
fn get_with<'a, 'key, Q: Query>(&'a self, key: &'key [u8], query: Q) -> Result