Network-Agnostic SputnikVM Patches
This crate provides re-exports of the DynamicPatch API, and a set of precompiled contracts covering everything up to ETH Constantinople
There are two major approaches to the EVM configuration:
Examples for both approaches may be found below
Dynamic Patch API
DynamicPatch API is most useful for multi-network clients like multi-geth, where it's preferable to configure the EVM feature-wise, instead of fork-wise.
Example
use evm::{SeqTransactionVM, ValidTransaction, TransactionAction, HeaderParams};
use evm_network::{DynamicPatch, DynamicAccountPatch, PRECOMPILEDS};
use bigint::{Gas, U256, Address};
use std::rc::Rc;
fn main() {
let transaction = ValidTransaction {
caller: Some(Address::default()),
gas_price: Gas::zero(),
gas_limit: Gas::max_value(),
action: TransactionAction::Create,
value: U256::zero(),
input: Rc::new(Vec::new()),
nonce: U256::zero()
};
// Block Header
let header = HeaderParams {
beneficiary: Address::default(),
timestamp: 0,
number: U256::zero(),
difficulty: U256::zero(),
gas_limit: Gas::zero()
};
// Account Patch for ETC MainNet
let account_patch = DynamicAccountPatch {
initial_nonce: U256::zero(),
initial_create_nonce: U256::zero(),
empty_considered_exists: true,
allow_partial_change: true
};
// Patch for Constantinople hardfork
let patch = DynamicPatch {
account_patch,
code_deposit_limit: None,
callstack_limit: 1024,
gas_extcode: Gas::from(700_usize),
gas_balance: Gas::from(400_usize),
gas_sload: Gas::from(200_usize),
gas_suicide: Gas::from(5000_usize),
gas_suicide_new_account: Gas::from(25000_usize),
gas_call: Gas::from(700_usize),
gas_expbyte: Gas::from(50_usize),
gas_transaction_create: Gas::from(32000_usize),
force_code_deposit: false,
has_delegate_call: true,
has_static_call: true,
has_revert: true,
has_return_data: true,
has_bitwise_shift: true,
has_extcodehash: true,
has_create2: true,
has_reduced_sstore_gas_metering: true,
err_on_call_with_more_gas: false,
call_create_l64_after_gas: true,
memory_limit: usize::max_value(),
// Enable all eight precompiled contracts by their addresses
enabled_precompileds: (0x1..=0x8).into_iter().map(Address::from).collect(),
precompileds: &PRECOMPILEDS
};
SeqTransactionVM::new(
&patch,
transaction,
header
);
}
Patch API
If you need just a single network or even a single feature-set, use the Patch trait directly, that allows to create custom feature sets without DynamicPatch's tiny overhead.
Example
use evm::{SeqTransactionVM, ValidTransaction, TransactionAction, HeaderParams, Precompiled};
use evm_network::{AccountPatch, Patch, PRECOMPILEDS};
use bigint::{Gas, U256, Address};
use std::rc::Rc;
struct MainnetAccountPatch;
impl AccountPatch for MainnetAccountPatch {
fn initial_nonce(&self) -> U256 { U256::zero() }
fn initial_create_nonce(&self) -> U256 { U256::zero() }
fn empty_considered_exists(&self) -> bool { true }
}
static MAINNET_ACCOUNT_PATCH: MainnetAccountPatch = MainnetAccountPatch;
struct ConstantinoplePatch;
impl Patch for ConstantinoplePatch {
type Account = MainnetAccountPatch;
fn account_patch(&self) -> &'static Self::Account { &MAINNET_ACCOUNT_PATCH }
fn code_deposit_limit(&self) -> Option<usize> { None }
fn callstack_limit(&self) -> usize { 1024 }
fn gas_extcode(&self) -> Gas { Gas::from(700usize) }
fn gas_balance(&self) -> Gas { Gas::from(400usize) }
fn gas_sload(&self) -> Gas { Gas::from(200usize) }
fn gas_suicide(&self) -> Gas { Gas::from(5000usize) }
fn gas_suicide_new_account(&self) -> Gas { Gas::from(25000usize) }
fn gas_call(&self) -> Gas { Gas::from(700usize) }
fn gas_expbyte(&self) -> Gas { Gas::from(50usize) }
fn gas_transaction_create(&self) -> Gas { Gas::from(32000usize) }
fn force_code_deposit(&self) -> bool { false }
fn has_delegate_call(&self) -> bool { true }
fn has_static_call(&self) -> bool { true }
fn has_revert(&self) -> bool { true }
fn has_return_data(&self) -> bool { true }
fn has_bitwise_shift(&self) -> bool { true }
fn has_create2(&self) -> bool { true }
fn has_extcodehash(&self) -> bool { true }
fn has_reduced_sstore_gas_metering(&self) -> bool { true }
fn err_on_call_with_more_gas(&self) -> bool { false }
fn call_create_l64_after_gas(&self) -> bool { true }
fn memory_limit(&self) -> usize { usize::max_value() }
fn is_precompiled_contract_enabled(&self, address: &Address) -> bool {
match address.low_u64() {
0x1 | 0x2 | 0x3 | 0x4 | 0x5 | 0x6 | 0x7 | 0x8 => true,
_ => false,
}
}
fn precompileds(&self) -> &'static [(Address, Option<&'static [u8]>, &'static Precompiled)] {
&PRECOMPILEDS
}
}
fn main() {
let transaction = ValidTransaction {
caller: Some(Address::default()),
gas_price: Gas::zero(),
gas_limit: Gas::max_value(),
action: TransactionAction::Create,
value: U256::zero(),
input: Rc::new(Vec::new()),
nonce: U256::zero()
};
// Block Header
let header = HeaderParams {
beneficiary: Address::default(),
timestamp: 0,
number: U256::zero(),
difficulty: U256::zero(),
gas_limit: Gas::zero()
};
let patch = ConstantinoplePatch;
SeqTransactionVM::new(
&patch,
transaction,
header
);
}