// 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 .
//! Transaction Execution environment.
use common::*;
use state::*;
use engine::*;
use executive::*;
use evm::{self, Schedule, Ext, ContractCreateResult, MessageCallResult};
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
}
/// Transaction properties that externalities need to know about.
pub struct OriginInfo {
address: Address,
origin: Address,
gas_price: U256,
value: U256
}
impl OriginInfo {
/// Populates origin info from action params.
pub fn from(params: &ActionParams) -> Self {
OriginInfo {
address: params.address.clone(),
origin: params.origin.clone(),
gas_price: params.gas_price.clone(),
value: match params.value {
ActionValue::Transfer(val) => val,
ActionValue::Apparent(val) => val,
}
}
}
}
/// Implementation of evm Externalities.
pub struct Externalities<'a> {
state: &'a mut State,
env_info: &'a EnvInfo,
engine: &'a Engine,
depth: usize,
origin_info: OriginInfo,
substate: &'a mut Substate,
schedule: Schedule,
output: OutputPolicy<'a>
}
impl<'a> Externalities<'a> {
/// Basic `Externalities` constructor.
pub fn new(state: &'a mut State,
env_info: &'a EnvInfo,
engine: &'a Engine,
depth: usize,
origin_info: OriginInfo,
substate: &'a mut Substate,
output: OutputPolicy<'a>) -> Self {
Externalities {
state: state,
env_info: env_info,
engine: engine,
depth: depth,
origin_info: origin_info,
substate: substate,
schedule: engine.schedule(env_info),
output: output
}
}
}
impl<'a> Ext for Externalities<'a> {
fn storage_at(&self, key: &H256) -> H256 {
self.state.storage_at(&self.origin_info.address, key)
}
fn set_storage(&mut self, key: H256, value: H256) {
self.state.set_storage(&self.origin_info.address, key, value)
}
fn exists(&self, address: &Address) -> bool {
self.state.exists(address)
}
fn balance(&self, address: &Address) -> U256 {
self.state.balance(address)
}
fn blockhash(&self, number: &U256) -> H256 {
match *number < U256::from(self.env_info.number) && number.low_u64() >= cmp::max(256, self.env_info.number) - 256 {
true => {
let index = self.env_info.number - number.low_u64() - 1;
let r = self.env_info.last_hashes[index as usize].clone();
trace!("ext: blockhash({}) -> {} self.env_info.number={}\n", number, r, self.env_info.number);
r
},
false => {
trace!("ext: blockhash({}) -> null self.env_info.number={}\n", number, self.env_info.number);
H256::from(&U256::zero())
},
}
}
fn create(&mut self, gas: &U256, value: &U256, code: &[u8]) -> ContractCreateResult {
// create new contract address
let address = contract_address(&self.origin_info.address, &self.state.nonce(&self.origin_info.address));
// prepare the params
let params = ActionParams {
code_address: address.clone(),
address: address.clone(),
sender: self.origin_info.address.clone(),
origin: self.origin_info.origin.clone(),
gas: *gas,
gas_price: self.origin_info.gas_price.clone(),
value: ActionValue::Transfer(value.clone()),
code: Some(code.to_vec()),
data: None,
};
self.state.inc_nonce(&self.origin_info.address);
let mut ex = Executive::from_parent(self.state, self.env_info, self.engine, self.depth);
// TODO: handle internal error separately
match ex.create(params, self.substate) {
Ok(gas_left) => {
self.substate.contracts_created.push(address.clone());
ContractCreateResult::Created(address, gas_left)
},
_ => ContractCreateResult::Failed
}
}
fn call(&mut self,
gas: &U256,
sender_address: &Address,
receive_address: &Address,
value: Option,
data: &[u8],
code_address: &Address,
output: &mut [u8]) -> MessageCallResult {
let mut params = ActionParams {
sender: sender_address.clone(),
address: receive_address.clone(),
value: ActionValue::Apparent(self.origin_info.value.clone()),
code_address: code_address.clone(),
origin: self.origin_info.origin.clone(),
gas: *gas,
gas_price: self.origin_info.gas_price.clone(),
code: self.state.code(code_address),
data: Some(data.to_vec()),
};
if let Some(value) = value {
params.value = ActionValue::Transfer(value);
}
let mut ex = Executive::from_parent(self.state, self.env_info, self.engine, self.depth);
match ex.call(params, self.substate, BytesRef::Fixed(output)) {
Ok(gas_left) => MessageCallResult::Success(gas_left),
_ => MessageCallResult::Failed
}
}
fn extcode(&self, address: &Address) -> Bytes {
self.state.code(address).unwrap_or_else(|| vec![])
}
#[allow(match_ref_pats)]
fn ret(&mut self, gas: &U256, data: &[u8]) -> Result {
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.origin_info.address;
self.state.init_code(address, code);
Ok(*gas - return_cost)
}
}
}
fn log(&mut self, topics: Vec, data: &[u8]) {
let address = self.origin_info.address.clone();
self.substate.logs.push(LogEntry::new(address, topics, data.to_vec()));
}
fn suicide(&mut self, refund_address: &Address) {
let address = self.origin_info.address.clone();
let balance = self.balance(&address);
if &address == refund_address {
// TODO [todr] To be consisted with CPP client we set balance to 0 in that case.
self.state.sub_balance(&address, &balance);
} else {
trace!("Suiciding {} -> {} (xfer: {})", address, refund_address, balance);
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.env_info
}
fn depth(&self) -> usize {
self.depth
}
fn inc_sstore_clears(&mut self) {
self.substate.sstore_clears_count = self.substate.sstore_clears_count + U256::one();
}
}