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simulator.rs
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360 lines (325 loc) · 10.6 KB
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use anyhow::{anyhow, Result};
use bytes::Bytes;
use ethers::abi;
use ethers::types::{Transaction, H160, U256, U64};
use ethers_providers::Middleware;
use foundry_evm::{
executor::{
fork::{BlockchainDb, BlockchainDbMeta, SharedBackend},
Bytecode, ExecutionResult, Output, TransactTo,
},
revm::{
db::{CacheDB, Database},
primitives::{keccak256, AccountInfo, U256 as rU256},
EVM,
},
};
use std::{collections::BTreeSet, str::FromStr, sync::Arc};
use crate::constants::SIMULATOR_CODE;
use crate::interfaces::{pool::V2PoolABI, simulator::SimulatorABI, token::TokenABI};
#[derive(Clone)]
pub struct EvmSimulator<M> {
pub provider: Arc<M>,
pub owner: H160,
pub evm: EVM<CacheDB<SharedBackend>>,
pub block_number: U64,
pub token: TokenABI,
pub v2_pool: V2PoolABI,
pub simulator: SimulatorABI,
pub simulator_address: H160,
}
#[derive(Debug, Clone)]
pub struct Tx {
pub caller: H160,
pub transact_to: H160,
pub data: Bytes,
pub value: U256,
pub gas_limit: u64,
}
#[derive(Debug, Clone)]
pub struct TxResult {
pub output: Bytes,
pub gas_used: u64,
pub gas_refunded: u64,
}
impl<M: Middleware + 'static> EvmSimulator<M> {
pub fn new(provider: Arc<M>, owner: H160, block_number: U64) -> Self {
let shared_backend = SharedBackend::spawn_backend_thread(
provider.clone(),
BlockchainDb::new(
BlockchainDbMeta {
cfg_env: Default::default(),
block_env: Default::default(),
hosts: BTreeSet::from(["".to_string()]),
},
None,
),
Some(block_number.into()),
);
let db = CacheDB::new(shared_backend);
let mut evm = EVM::new();
evm.database(db);
evm.env.cfg.limit_contract_code_size = Some(0x100000);
evm.env.cfg.disable_block_gas_limit = true;
evm.env.cfg.disable_base_fee = true;
evm.env.block.number = rU256::from(block_number.as_u64() + 1);
Self {
provider,
owner,
evm,
block_number,
token: TokenABI::new(),
v2_pool: V2PoolABI::new(),
simulator: SimulatorABI::new(),
simulator_address: H160::from_str("0x4E17607Fb72C01C280d7b5c41Ba9A2109D74a32C")
.unwrap(),
}
}
pub fn inject_db(&mut self, db: CacheDB<SharedBackend>) {
self.evm.database(db);
}
pub fn run_pending_tx(&mut self, tx: &Transaction) -> Result<TxResult> {
// We simply need to commit changes to the DB
self.evm.env.tx.caller = tx.from.0.into();
self.evm.env.tx.transact_to = TransactTo::Call(tx.to.unwrap_or_default().0.into());
self.evm.env.tx.data = tx.input.0.clone();
self.evm.env.tx.value = tx.value.into();
self.evm.env.tx.chain_id = tx.chain_id.map(|id| id.as_u64());
self.evm.env.tx.gas_limit = tx.gas.as_u64();
match tx.transaction_type {
Some(U64([0])) => self.evm.env.tx.gas_price = tx.gas_price.unwrap_or_default().into(),
Some(_) => {
self.evm.env.tx.gas_priority_fee =
tx.max_priority_fee_per_gas.map(|mpf| mpf.into());
self.evm.env.tx.gas_price = tx.max_fee_per_gas.unwrap_or_default().into();
}
None => self.evm.env.tx.gas_price = tx.gas_price.unwrap_or_default().into(),
}
let result = match self.evm.transact_commit() {
Ok(result) => result,
Err(e) => return Err(anyhow!("EVM call failed: {:?}", e)),
};
let output = match result {
ExecutionResult::Success {
gas_used,
gas_refunded,
output,
..
} => match output {
Output::Call(o) => TxResult {
output: o,
gas_used,
gas_refunded,
},
Output::Create(o, _) => TxResult {
output: o,
gas_used,
gas_refunded,
},
},
ExecutionResult::Revert { gas_used, output } => {
return Err(anyhow!(
"EVM REVERT: {:?} / Gas used: {:?}",
output,
gas_used
))
}
ExecutionResult::Halt { reason, .. } => return Err(anyhow!("EVM HALT: {:?}", reason)),
};
Ok(output)
}
pub fn _call(&mut self, tx: Tx, commit: bool) -> Result<TxResult> {
self.evm.env.tx.caller = tx.caller.into();
self.evm.env.tx.transact_to = TransactTo::Call(tx.transact_to.into());
self.evm.env.tx.data = tx.data;
self.evm.env.tx.value = tx.value.into();
self.evm.env.tx.gas_limit = 5000000;
let result;
if commit {
result = match self.evm.transact_commit() {
Ok(result) => result,
Err(e) => return Err(anyhow!("EVM call failed: {:?}", e)),
};
} else {
let ref_tx = self
.evm
.transact_ref()
.map_err(|e| anyhow!("EVM staticcall failed: {:?}", e))?;
result = ref_tx.result;
}
let output = match result {
ExecutionResult::Success {
gas_used,
gas_refunded,
output,
..
} => match output {
Output::Call(o) => TxResult {
output: o,
gas_used,
gas_refunded,
},
Output::Create(o, _) => TxResult {
output: o,
gas_used,
gas_refunded,
},
},
ExecutionResult::Revert { gas_used, output } => {
return Err(anyhow!(
"EVM REVERT: {:?} / Gas used: {:?}",
output,
gas_used
))
}
ExecutionResult::Halt { reason, .. } => return Err(anyhow!("EVM HALT: {:?}", reason)),
};
Ok(output)
}
pub fn staticcall(&mut self, tx: Tx) -> Result<TxResult> {
self._call(tx, false)
}
pub fn call(&mut self, tx: Tx) -> Result<TxResult> {
self._call(tx, true)
}
pub fn get_eth_balance(&mut self) -> U256 {
let acc = self
.evm
.db
.as_mut()
.unwrap()
.basic(self.owner.into())
.unwrap()
.unwrap();
acc.balance.into()
}
pub fn set_eth_balance(&mut self, balance: u32) {
let user_balance = rU256::from(balance)
.checked_mul(rU256::from(10).pow(rU256::from(18)))
.unwrap();
let user_info = AccountInfo::new(user_balance, 0, Bytecode::default());
self.evm
.db
.as_mut()
.unwrap()
.insert_account_info(self.owner.into(), user_info);
}
// ERC-20 Token functions
pub fn set_token_balance(
&mut self,
account: H160,
token: H160,
decimals: u8,
slot: u32,
balance: u32,
) {
let slot = keccak256(&abi::encode(&[
abi::Token::Address(account.into()),
abi::Token::Uint(U256::from(slot)),
]));
let target_balance = rU256::from(balance)
.checked_mul(rU256::from(10).pow(rU256::from(decimals)))
.unwrap();
self.evm
.db
.as_mut()
.unwrap()
.insert_account_storage(token.into(), slot.into(), target_balance)
.unwrap();
}
pub fn token_balance_of(&mut self, token: H160, account: H160) -> Result<U256> {
let calldata = self.token.balance_of_input(account)?;
let value = self.staticcall(Tx {
caller: self.owner.into(),
transact_to: token,
data: calldata.0,
value: U256::zero(),
gas_limit: 0,
})?;
let out = self.token.balance_of_output(value.output)?;
Ok(out)
}
// V2 Pool functions
pub fn set_v2_pool_reserves(&mut self, pool: H160, reserves: rU256) {
let slot = rU256::from(8);
self.evm
.db
.as_mut()
.unwrap()
.insert_account_storage(pool.into(), slot.into(), reserves)
.unwrap();
}
pub fn v2_pool_get_reserves(&mut self, pool: H160) -> Result<(u128, u128, u32)> {
let calldata = self.v2_pool.get_reserves_input()?;
let value = self.staticcall(Tx {
caller: self.owner,
transact_to: pool,
data: calldata.0,
value: U256::zero(),
gas_limit: 0,
})?;
let out = self.v2_pool.get_reserves_output(value.output)?;
Ok(out)
}
// Simulator functions
pub fn deploy_simulator(&mut self) {
let contract_info = AccountInfo::new(
rU256::ZERO,
0,
Bytecode::new_raw((*SIMULATOR_CODE.0).into()),
);
self.evm
.db
.as_mut()
.unwrap()
.insert_account_info(self.simulator_address.into(), contract_info);
}
pub fn v2_simulate_swap(
&mut self,
amount_in: U256,
target_pool: H160,
input_token: H160,
output_token: H160,
commit: bool,
) -> Result<(U256, U256)> {
let calldata = self.simulator.v2_simulate_swap_input(
amount_in,
target_pool,
input_token,
output_token,
)?;
let tx = Tx {
caller: self.owner,
transact_to: self.simulator_address,
data: calldata.0,
value: U256::zero(),
gas_limit: 5000000,
};
let value = if commit {
self.call(tx)?
} else {
self.staticcall(tx)?
};
let out = self.simulator.v2_simulate_swap_output(value.output)?;
Ok(out)
}
pub fn get_amount_out(
&mut self,
amount_in: U256,
reserve_in: U256,
reserve_out: U256,
) -> Result<U256> {
let calldata = self
.simulator
.get_amount_out_input(amount_in, reserve_in, reserve_out)?;
let value = self.staticcall(Tx {
caller: self.owner,
transact_to: self.simulator_address,
data: calldata.0,
value: U256::zero(),
gas_limit: 5000000,
})?;
let out = self.simulator.get_amount_out_output(value.output)?;
Ok(out)
}
}