openethereum/src/state.rs
2016-01-15 04:02:06 +01:00

427 lines
12 KiB
Rust

use common::*;
use engine::Engine;
use executive::Executive;
use pod_account::*;
use pod_state::*;
pub type ApplyResult = Result<Receipt, Error>;
/// Representation of the entire state of all accounts in the system.
#[derive(Clone)]
pub struct State {
db: OverlayDB,
root: H256,
cache: RefCell<HashMap<Address, Option<Account>>>,
account_start_nonce: U256,
}
impl State {
/// Creates new state with empty state root
pub fn new(mut db: OverlayDB, account_start_nonce: U256) -> State {
let mut root = H256::new();
{
// init trie and reset root too null
let _ = SecTrieDBMut::new(&mut db, &mut root);
}
State {
db: db,
root: root,
cache: RefCell::new(HashMap::new()),
account_start_nonce: account_start_nonce,
}
}
/// Creates new state with existing state root
pub fn from_existing(db: OverlayDB, root: H256, account_start_nonce: U256) -> State {
{
// trie should panic! if root does not exist
let _ = SecTrieDB::new(&db, &root);
}
State {
db: db,
root: root,
cache: RefCell::new(HashMap::new()),
account_start_nonce: account_start_nonce,
}
}
/// Create temporary state object
pub fn new_temp() -> State {
Self::new(OverlayDB::new_temp(), U256::from(0u8))
}
/// Destroy the current object and return root and database.
pub fn drop(self) -> (H256, OverlayDB) {
(self.root, self.db)
}
/// Return reference to root
pub fn root(&self) -> &H256 {
&self.root
}
/// Expose the underlying database; good to use for calling `state.db().commit()`.
pub fn db(&mut self) -> &mut OverlayDB {
&mut self.db
}
/// Create a new contract at address `contract`. If there is already an account at the address
/// it will have its code reset, ready for `init_code()`.
pub fn new_contract(&mut self, contract: &Address) {
self.require_or_from(contract, false, || Account::new_contract(U256::from(0u8)), |r| r.reset_code());
}
/// Remove an existing account.
pub fn kill_account(&mut self, account: &Address) {
self.cache.borrow_mut().insert(account.clone(), None);
}
/// Determine whether an account exists.
pub fn exists(&self, a: &Address) -> bool {
self.cache.borrow().get(&a).unwrap_or(&None).is_some() || SecTrieDB::new(&self.db, &self.root).contains(&a)
}
/// Get the balance of account `a`.
pub fn balance(&self, a: &Address) -> U256 {
self.get(a, false).as_ref().map(|account| account.balance().clone()).unwrap_or(U256::from(0u8))
}
/// Get the nonce of account `a`.
pub fn nonce(&self, a: &Address) -> U256 {
self.get(a, false).as_ref().map(|account| account.nonce().clone()).unwrap_or(U256::from(0u8))
}
/// Mutate storage of account `a` so that it is `value` for `key`.
pub fn storage_at(&self, a: &Address, key: &H256) -> H256 {
self.get(a, false).as_ref().map(|a|a.storage_at(&self.db, key)).unwrap_or(H256::new())
}
/// Mutate storage of account `a` so that it is `value` for `key`.
pub fn code(&self, a: &Address) -> Option<Vec<u8>> {
self.get(a, true).as_ref().map(|a|a.code().map(|x|x.to_vec())).unwrap_or(None)
}
/// Add `incr` to the balance of account `a`.
pub fn add_balance(&mut self, a: &Address, incr: &U256) {
self.require(a, false).add_balance(incr)
}
/// Subtract `decr` from the balance of account `a`.
pub fn sub_balance(&mut self, a: &Address, decr: &U256) {
self.require(a, false).sub_balance(decr)
}
/// Subtracts `by` from the balance of `from` and adds it to that of `to`.
pub fn transfer_balance(&mut self, from: &Address, to: &Address, by: &U256) {
self.sub_balance(from, by);
self.add_balance(to, by);
}
/// Increment the nonce of account `a` by 1.
pub fn inc_nonce(&mut self, a: &Address) {
self.require(a, false).inc_nonce()
}
/// Mutate storage of account `a` so that it is `value` for `key`.
pub fn set_storage(&mut self, a: &Address, key: H256, value: H256) {
self.require(a, false).set_storage(key, value)
}
/// Initialise the code of account `a` so that it is `value` for `key`.
/// NOTE: Account should have been created with `new_contract`.
pub fn init_code(&mut self, a: &Address, code: Bytes) {
self.require_or_from(a, true, || Account::new_contract(U256::from(0u8)), |_|{}).init_code(code);
}
/// Execute a given transaction.
/// This will change the state accordingly.
pub fn apply(&mut self, env_info: &EnvInfo, engine: &Engine, t: &Transaction) -> ApplyResult {
let e = try!(Executive::new(self, env_info, engine).transact(t));
//println!("Executed: {:?}", e);
self.commit();
Ok(Receipt::new(self.root().clone(), e.cumulative_gas_used, e.logs))
}
pub fn revert(&mut self, backup: State) {
self.cache = backup.cache;
}
/// Convert into a JSON representation.
pub fn as_json(&self) -> String {
unimplemented!();
}
/// Commit accounts to SecTrieDBMut. This is similar to cpp-ethereum's dev::eth::commit.
/// `accounts` is mutable because we may need to commit the code or storage and record that.
pub fn commit_into(db: &mut HashDB, root: &mut H256, accounts: &mut HashMap<Address, Option<Account>>) {
// first, commit the sub trees.
// TODO: is this necessary or can we dispense with the `ref mut a` for just `a`?
for (_, ref mut a) in accounts.iter_mut() {
match a {
&mut&mut Some(ref mut account) => {
account.commit_storage(db);
account.commit_code(db);
}
&mut&mut None => {}
}
}
{
let mut trie = SecTrieDBMut::from_existing(db, root);
for (address, ref a) in accounts.iter() {
match a {
&&Some(ref account) => trie.insert(address, &account.rlp()),
&&None => trie.remove(address),
}
}
}
}
/// Commits our cached account changes into the trie.
pub fn commit(&mut self) {
Self::commit_into(&mut self.db, &mut self.root, self.cache.borrow_mut().deref_mut());
}
/// Populate the state from `accounts`.
pub fn populate_from(&mut self, accounts: PodState) {
for (add, acc) in accounts.drain().into_iter() {
self.cache.borrow_mut().insert(add, Some(Account::from_pod(acc)));
}
}
/// Populate a PodAccount map from this state.
pub fn to_hashmap_pod(&self) -> HashMap<Address, PodAccount> {
// TODO: handle database rather than just the cache.
self.cache.borrow().iter().fold(HashMap::new(), |mut m, (add, opt)| {
if let &Some(ref acc) = opt {
m.insert(add.clone(), PodAccount::from_account(acc));
}
m
})
}
/// Populate a PodAccount map from this state.
pub fn to_pod(&self) -> PodState {
// TODO: handle database rather than just the cache.
PodState::new(self.cache.borrow().iter().fold(BTreeMap::new(), |mut m, (add, opt)| {
if let &Some(ref acc) = opt {
m.insert(add.clone(), PodAccount::from_account(acc));
}
m
}))
}
/// Pull account `a` in our cache from the trie DB and return it.
/// `require_code` requires that the code be cached, too.
fn get(&self, a: &Address, require_code: bool) -> Ref<Option<Account>> {
self.cache.borrow_mut().entry(a.clone()).or_insert_with(||
SecTrieDB::new(&self.db, &self.root).get(&a).map(|rlp| Account::from_rlp(rlp)));
if require_code {
if let Some(ref mut account) = self.cache.borrow_mut().get_mut(a).unwrap().as_mut() {
account.cache_code(&self.db);
}
}
Ref::map(self.cache.borrow(), |m| m.get(a).unwrap())
}
/// Pull account `a` in our cache from the trie DB. `require_code` requires that the code be cached, too.
fn require(&self, a: &Address, require_code: bool) -> RefMut<Account> {
self.require_or_from(a, require_code, || Account::new_basic(U256::from(0u8), self.account_start_nonce), |_|{})
}
/// Pull account `a` in our cache from the trie DB. `require_code` requires that the code be cached, too.
/// If it doesn't exist, make account equal the evaluation of `default`.
fn require_or_from<F: FnOnce() -> Account, G: FnOnce(&mut Account)>(&self, a: &Address, require_code: bool, default: F, not_default: G) -> RefMut<Account> {
self.cache.borrow_mut().entry(a.clone()).or_insert_with(||
SecTrieDB::new(&self.db, &self.root).get(&a).map(|rlp| Account::from_rlp(rlp)));
let preexists = self.cache.borrow().get(a).unwrap().is_none();
if preexists {
self.cache.borrow_mut().insert(a.clone(), Some(default()));
} else {
not_default(self.cache.borrow_mut().get_mut(a).unwrap().as_mut().unwrap());
}
let b = self.cache.borrow_mut();
RefMut::map(b, |m| m.get_mut(a).unwrap().as_mut().map(|account| {
if require_code {
account.cache_code(&self.db);
}
account
}).unwrap())
}
}
impl fmt::Debug for State {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "{:?}", self.cache.borrow())
}
}
#[cfg(test)]
mod tests {
use super::*;
use util::hash::*;
use util::trie::*;
use util::rlp::*;
use util::uint::*;
use account::*;
#[test]
fn code_from_database() {
let a = Address::zero();
let (r, db) = {
let mut s = State::new_temp();
s.require_or_from(&a, false, ||Account::new_contract(U256::from(42u32)), |_|{});
s.init_code(&a, vec![1, 2, 3]);
assert_eq!(s.code(&a), Some([1u8, 2, 3].to_vec()));
s.commit();
assert_eq!(s.code(&a), Some([1u8, 2, 3].to_vec()));
s.drop()
};
let s = State::from_existing(db, r, U256::from(0u8));
assert_eq!(s.code(&a), Some([1u8, 2, 3].to_vec()));
}
#[test]
fn storage_at_from_database() {
let a = Address::zero();
let (r, db) = {
let mut s = State::new_temp();
s.set_storage(&a, H256::from(&U256::from(01u64)), H256::from(&U256::from(69u64)));
s.commit();
s.drop()
};
let s = State::from_existing(db, r, U256::from(0u8));
assert_eq!(s.storage_at(&a, &H256::from(&U256::from(01u64))), H256::from(&U256::from(69u64)));
}
#[test]
fn get_from_database() {
let a = Address::zero();
let (r, db) = {
let mut s = State::new_temp();
s.inc_nonce(&a);
s.add_balance(&a, &U256::from(69u64));
s.commit();
assert_eq!(s.balance(&a), U256::from(69u64));
s.drop()
};
let s = State::from_existing(db, r, U256::from(0u8));
assert_eq!(s.balance(&a), U256::from(69u64));
assert_eq!(s.nonce(&a), U256::from(1u64));
}
#[test]
fn remove() {
let a = Address::zero();
let mut s = State::new_temp();
assert_eq!(s.exists(&a), false);
s.inc_nonce(&a);
assert_eq!(s.exists(&a), true);
assert_eq!(s.nonce(&a), U256::from(1u64));
s.kill_account(&a);
assert_eq!(s.exists(&a), false);
assert_eq!(s.nonce(&a), U256::from(0u64));
}
#[test]
fn remove_from_database() {
let a = Address::zero();
let (r, db) = {
let mut s = State::new_temp();
s.inc_nonce(&a);
s.commit();
assert_eq!(s.exists(&a), true);
assert_eq!(s.nonce(&a), U256::from(1u64));
s.drop()
};
let (r, db) = {
let mut s = State::from_existing(db, r, U256::from(0u8));
assert_eq!(s.exists(&a), true);
assert_eq!(s.nonce(&a), U256::from(1u64));
s.kill_account(&a);
s.commit();
assert_eq!(s.exists(&a), false);
assert_eq!(s.nonce(&a), U256::from(0u64));
s.drop()
};
let s = State::from_existing(db, r, U256::from(0u8));
assert_eq!(s.exists(&a), false);
assert_eq!(s.nonce(&a), U256::from(0u64));
}
#[test]
fn alter_balance() {
let mut s = State::new_temp();
let a = Address::zero();
let b = address_from_u64(1u64);
s.add_balance(&a, &U256::from(69u64));
assert_eq!(s.balance(&a), U256::from(69u64));
s.commit();
assert_eq!(s.balance(&a), U256::from(69u64));
s.sub_balance(&a, &U256::from(42u64));
assert_eq!(s.balance(&a), U256::from(27u64));
s.commit();
assert_eq!(s.balance(&a), U256::from(27u64));
s.transfer_balance(&a, &b, &U256::from(18u64));
assert_eq!(s.balance(&a), U256::from(9u64));
assert_eq!(s.balance(&b), U256::from(18u64));
s.commit();
assert_eq!(s.balance(&a), U256::from(9u64));
assert_eq!(s.balance(&b), U256::from(18u64));
}
#[test]
fn alter_nonce() {
let mut s = State::new_temp();
let a = Address::zero();
s.inc_nonce(&a);
assert_eq!(s.nonce(&a), U256::from(1u64));
s.inc_nonce(&a);
assert_eq!(s.nonce(&a), U256::from(2u64));
s.commit();
assert_eq!(s.nonce(&a), U256::from(2u64));
s.inc_nonce(&a);
assert_eq!(s.nonce(&a), U256::from(3u64));
s.commit();
assert_eq!(s.nonce(&a), U256::from(3u64));
}
#[test]
fn balance_nonce() {
let mut s = State::new_temp();
let a = Address::zero();
assert_eq!(s.balance(&a), U256::from(0u64));
assert_eq!(s.nonce(&a), U256::from(0u64));
s.commit();
assert_eq!(s.balance(&a), U256::from(0u64));
assert_eq!(s.nonce(&a), U256::from(0u64));
}
#[test]
fn ensure_cached() {
let mut s = State::new_temp();
let a = Address::zero();
s.require(&a, false);
s.commit();
assert_eq!(s.root().hex(), "0ce23f3c809de377b008a4a3ee94a0834aac8bec1f86e28ffe4fdb5a15b0c785");
}
#[test]
fn create_empty() {
let mut s = State::new_temp();
s.commit();
assert_eq!(s.root().hex(), "56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421");
}
}