openethereum/src/externalities.rs
2016-01-16 01:48:38 +01:00

250 lines
7.8 KiB
Rust

//! Transaction Execution environment.
use common::*;
use state::*;
use engine::*;
use executive::*;
use evm::{self, Schedule, Ext};
use substate::*;
/// Policy for handling output data on `RETURN` opcode.
pub enum OutputPolicy<'a> {
/// Return reference to fixed sized output.
/// Used for message calls.
Return(BytesRef<'a>),
/// Init new contract as soon as `RETURN` is called.
InitContract
}
/// Implementation of evm Externalities.
pub struct Externalities<'a> {
#[cfg(test)]
pub state: &'a mut State,
#[cfg(not(test))]
state: &'a mut State,
info: &'a EnvInfo,
engine: &'a Engine,
depth: usize,
#[cfg(test)]
pub params: &'a ActionParams,
#[cfg(not(test))]
params: &'a ActionParams,
substate: &'a mut Substate,
schedule: Schedule,
output: OutputPolicy<'a>
}
impl<'a> Externalities<'a> {
/// Basic `Externalities` constructor.
pub fn new(state: &'a mut State,
info: &'a EnvInfo,
engine: &'a Engine,
depth: usize,
params: &'a ActionParams,
substate: &'a mut Substate,
output: OutputPolicy<'a>) -> Self {
Externalities {
state: state,
info: info,
engine: engine,
depth: depth,
params: params,
substate: substate,
schedule: engine.schedule(info),
output: output
}
}
}
impl<'a> Ext for Externalities<'a> {
fn storage_at(&self, key: &H256) -> H256 {
trace!("ext: storage_at({}, {}) == {}\n", self.params.address, key, U256::from(self.state.storage_at(&self.params.address, key).as_slice()));
self.state.storage_at(&self.params.address, key)
}
fn set_storage_at(&mut self, key: H256, value: H256) {
let old = self.state.storage_at(&self.params.address, &key);
// if SSTORE nonzero -> zero, increment refund count
if value.is_zero() && !old.is_zero() {
trace!("ext: additional refund. {} -> {}\n", self.substate.refunds_count, self.substate.refunds_count + x!(1));
self.substate.refunds_count = self.substate.refunds_count + U256::one();
}
trace!("ext: set_storage_at({}, {}): {} -> {}\n", self.params.address, key, U256::from(old.as_slice()), U256::from(value.as_slice()));
self.state.set_storage(&self.params.address, key, value)
}
fn balance(&self, address: &Address) -> U256 {
self.state.balance(address)
}
fn blockhash(&self, number: &U256) -> H256 {
match *number < U256::from(self.info.number) && number.low_u64() >= cmp::max(256, self.info.number) - 256 {
true => {
let index = self.info.number - number.low_u64() - 1;
let r = self.info.last_hashes[index as usize].clone();
trace!("ext: blockhash({}) -> {} self.info.number={}\n", number, r, self.info.number);
r
},
false => {
trace!("ext: blockhash({}) -> null self.info.number={}\n", number, self.info.number);
H256::from(&U256::zero())
},
}
}
fn create(&mut self, gas: &U256, value: &U256, code: &[u8]) -> (U256, Option<Address>) {
// if balance is insufficient or we are to deep, return
if self.state.balance(&self.params.address) < *value || self.depth >= self.schedule.max_depth {
return (*gas, None);
}
// create new contract address
let address = contract_address(&self.params.address, &self.state.nonce(&self.params.address));
// prepare the params
let params = ActionParams {
code_address: address.clone(),
address: address.clone(),
sender: self.params.address.clone(),
origin: self.params.origin.clone(),
gas: *gas,
gas_price: self.params.gas_price.clone(),
value: value.clone(),
code: Some(code.to_vec()),
data: None,
};
self.state.inc_nonce(&self.params.address);
let mut ex = Executive::from_parent(self.state, self.info, self.engine, self.depth);
match ex.create(&params, self.substate) {
Ok(gas_left) => (gas_left, Some(address)),
_ => (U256::zero(), None)
}
}
fn call(&mut self,
gas: &U256,
call_gas: &U256,
receive_address: &Address,
value: &U256,
data: &[u8],
code_address: &Address,
output: &mut [u8]) -> Result<(U256, bool), evm::Error> {
let mut gas_cost = *call_gas;
let mut call_gas = *call_gas;
let is_call = receive_address == code_address;
if is_call && !self.state.exists(&code_address) {
gas_cost = gas_cost + U256::from(self.schedule.call_new_account_gas);
}
if *value > U256::zero() {
assert!(self.schedule.call_value_transfer_gas > self.schedule.call_stipend, "overflow possible");
gas_cost = gas_cost + U256::from(self.schedule.call_value_transfer_gas);
call_gas = call_gas + U256::from(self.schedule.call_stipend);
}
debug!("Externalities::call(gas={}, call_gas={}, recv={}, value={}, data={}, code={})\n", gas, call_gas, receive_address, value, data.pretty(), code_address);
if gas_cost > *gas {
debug!("Externalities::call: OutOfGas gas_cost={}, gas={}", gas_cost, gas);
return Err(evm::Error::OutOfGas);
}
let gas = *gas - gas_cost;
// if balance is insufficient or we are too deep, return
if self.state.balance(&self.params.address) < *value || self.depth >= self.schedule.max_depth {
debug!("Externalities::call: OutOfCash bal({})={}, value={}", self.params.address, self.state.balance(&self.params.address), value);
return Ok((gas + call_gas, false));
}
let params = ActionParams {
code_address: code_address.clone(),
address: receive_address.clone(),
sender: self.params.address.clone(),
origin: self.params.origin.clone(),
gas: call_gas,
gas_price: self.params.gas_price.clone(),
value: value.clone(),
code: self.state.code(code_address),
data: Some(data.to_vec()),
};
trace!("Externalities::call: BEFORE: bal({})={}, bal({})={}\n", params.sender, self.state.balance(&params.sender), params.address, self.state.balance(&params.address));
trace!("Externalities::call: CALLING: params={:?}\n", params);
let r = Executive::from_parent(self.state, self.info, self.engine, self.depth).call(&params, self.substate, BytesRef::Fixed(output));
trace!("Externalities::call: AFTER: bal({})={}, bal({})={}\n", params.sender, self.state.balance(&params.sender), params.address, self.state.balance(&params.address));
match r {
Ok(gas_left) => Ok((gas + gas_left, true)),
_ => Ok((gas, false))
}
}
fn extcode(&self, address: &Address) -> Vec<u8> {
self.state.code(address).unwrap_or(vec![])
}
fn ret(&mut self, gas: &U256, data: &[u8]) -> Result<U256, evm::Error> {
match &mut self.output {
&mut OutputPolicy::Return(BytesRef::Fixed(ref mut slice)) => unsafe {
let len = cmp::min(slice.len(), data.len());
ptr::copy(data.as_ptr(), slice.as_mut_ptr(), len);
Ok(*gas)
},
&mut OutputPolicy::Return(BytesRef::Flexible(ref mut vec)) => unsafe {
vec.clear();
vec.reserve(data.len());
ptr::copy(data.as_ptr(), vec.as_mut_ptr(), data.len());
vec.set_len(data.len());
Ok(*gas)
},
&mut OutputPolicy::InitContract => {
let return_cost = U256::from(data.len()) * U256::from(self.schedule.create_data_gas);
if return_cost > *gas {
return match self.schedule.exceptional_failed_code_deposit {
true => Err(evm::Error::OutOfGas),
false => Ok(*gas)
}
}
let mut code = vec![];
code.reserve(data.len());
unsafe {
ptr::copy(data.as_ptr(), code.as_mut_ptr(), data.len());
code.set_len(data.len());
}
let address = &self.params.address;
self.state.init_code(address, code);
self.substate.contracts_created.push(address.clone());
Ok(*gas - return_cost)
}
}
}
fn log(&mut self, topics: Vec<H256>, data: Bytes) {
let address = self.params.address.clone();
self.substate.logs.push(LogEntry::new(address, topics, data));
}
fn suicide(&mut self, refund_address: &Address) {
let address = self.params.address.clone();
let balance = self.balance(&address);
self.state.transfer_balance(&address, refund_address, &balance);
self.substate.suicides.insert(address);
}
fn schedule(&self) -> &Schedule {
&self.schedule
}
fn env_info(&self) -> &EnvInfo {
&self.info
}
}