openethereum/ethcore/src/account_db.rs

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2016-02-05 01:49:17 +01:00
//! DB backend wrapper for Account trie
use util::*;
static NULL_RLP_STATIC: [u8; 1] = [0x80; 1];
// TODO: introduce HashDBMut?
/// DB backend wrapper for Account trie
/// Transforms trie node keys for the database
pub struct AccountDB<'db> {
db: &'db HashDB,
address: H256,
}
#[inline]
fn combine_key<'a>(address: &'a H256, key: &'a H256) -> H256 {
let mut addr_hash = address.sha3();
// preserve 96 bits of original key for db lookup
addr_hash[0..12].clone_from_slice(&[0u8; 12]);
&addr_hash ^ key
2016-02-05 01:49:17 +01:00
}
impl<'db> AccountDB<'db> {
pub fn new(db: &'db HashDB, address: &Address) -> AccountDB<'db> {
AccountDB {
db: db,
address: x!(address.clone()),
}
}
}
impl<'db> HashDB for AccountDB<'db>{
fn keys(&self) -> HashMap<H256, i32> {
unimplemented!()
}
fn lookup(&self, key: &H256) -> Option<&[u8]> {
if key == &SHA3_NULL_RLP {
return Some(&NULL_RLP_STATIC);
}
self.db.lookup(&combine_key(&self.address, key))
}
fn exists(&self, key: &H256) -> bool {
if key == &SHA3_NULL_RLP {
return true;
}
self.db.exists(&combine_key(&self.address, key))
}
fn insert(&mut self, _value: &[u8]) -> H256 {
unimplemented!()
}
fn emplace(&mut self, _key: H256, _value: Bytes) {
unimplemented!()
}
fn kill(&mut self, _key: &H256) {
unimplemented!()
}
}
/// DB backend wrapper for Account trie
pub struct AccountDBMut<'db> {
db: &'db mut HashDB,
address: H256,
}
impl<'db> AccountDBMut<'db> {
pub fn new(db: &'db mut HashDB, address: &Address) -> AccountDBMut<'db> {
AccountDBMut {
db: db,
address: x!(address.clone()),
}
}
#[allow(dead_code)]
pub fn immutable(&'db self) -> AccountDB<'db> {
AccountDB { db: self.db, address: self.address.clone() }
}
}
impl<'db> HashDB for AccountDBMut<'db>{
fn keys(&self) -> HashMap<H256, i32> {
unimplemented!()
}
fn lookup(&self, key: &H256) -> Option<&[u8]> {
if key == &SHA3_NULL_RLP {
return Some(&NULL_RLP_STATIC);
}
self.db.lookup(&combine_key(&self.address, key))
}
fn exists(&self, key: &H256) -> bool {
if key == &SHA3_NULL_RLP {
return true;
}
self.db.exists(&combine_key(&self.address, key))
}
fn insert(&mut self, value: &[u8]) -> H256 {
let k = value.sha3();
let ak = combine_key(&self.address, &k);
self.db.emplace(ak, value.to_vec());
k
}
fn emplace(&mut self, key: H256, value: Bytes) {
let key = combine_key(&self.address, &key);
self.db.emplace(key, value.to_vec())
}
fn kill(&mut self, key: &H256) {
let key = combine_key(&self.address, key);
self.db.kill(&key)
}
}