Crate pallet_evm

EVM Pallet

The EVM pallet allows unmodified EVM code to be executed in a Substrate-based blockchain.

• evm::Config

EVM Engine

The EVM pallet uses SputnikVM as the underlying EVM engine. The engine is overhauled so that it’s modular.

Execution Lifecycle

There are a separate set of accounts managed by the EVM pallet. Substrate based accounts can call the EVM Pallet to deposit or withdraw balance from the Substrate base-currency into a different balance managed and used by the EVM pallet. Once a user has populated their balance, they can create and call smart contracts using this pallet.

There’s one-to-one mapping from Substrate accounts and EVM external accounts that is defined by a conversion function.

EVM Pallet vs Ethereum Network

The EVM pallet should be able to produce nearly identical results compared to the Ethereum mainnet, including gas cost and balance changes.

Observable differences include:

• The available length of block hashes may not be 256 depending on the configuration of the System pallet in the Substrate runtime.
• Difficulty and coinbase, which do not make sense in this pallet and is currently hard coded to zero.

We currently do not aim to make unobservable behaviors, such as state root, to be the same. We also don’t aim to follow the exact same transaction / receipt format. However, given one Ethereum transaction and one Substrate account’s private key, one should be able to convert any Ethereum transaction into a transaction compatible with this pallet.

The gas configurations are configurable. Right now, a pre-defined London hard fork configuration option is provided.

Re-exports

pub use self::runner::Runner;

pub use self::runner::RunnerError;

pub use self::weights::WeightInfo;

pub use self::pallet::*;

Modules

pallet

The pallet module in each FRAME pallet hosts the most important items needed to construct this pallet.

runner

weights

Autogenerated weights for pallet_evm

Structs

Account

Basic account information.

CodeMetadata

Context

Context of the runtime.

EVMCurrencyAdapter

Implements the transaction payment for a pallet implementing the Currency trait (eg. the pallet_balances) using an unbalance handler (implementing OnUnbalanced). Similar to CurrencyAdapter of pallet_transaction_payment

EVMFungibleAdapter

Implements transaction payment for a pallet implementing the [fungible] trait (eg. pallet_balances) using an unbalance handler (implementing [OnUnbalanced]).

EnsureAccountId20

Ensure that the address is AccountId20.

EnsureAddressNever

Ensure that the origin never happens.

EnsureAddressRoot

Ensure that the origin is root.

EnsureAddressSame

Ensure that the EVM address is the same as the Substrate address. This only works if the account ID is H160.

EnsureAddressTruncated

Ensure that the address is truncated hash of the origin. Only works if the account id is AccountId32.

EnsureAllowedCreateAddress

EvmConfig

Runtime configuration.

ExecutionInfo

FixedGasWeightMapping

FrameSystemAccountProvider

EVM account provider based on the [frame_system] accounts.

HashedAddressMapping

Hashed address mapping.

IdentityAddressMapping

Identity address mapping.

Log

PrecompileOutput

Data returned by a precompile on success.

SubstrateBlockHashMapping

Returns the Substrate block hash by number.

Vicinity

External input from the transaction.

Enums

ExitError

Exit error reason.

ExitFatal

Exit fatal reason.

ExitReason

Exit reason.

ExitRevert

Exit revert reason.

ExitSucceed

Exit succeed reason.

IsPrecompileResult

PrecompileFailure

Data returned by a precompile in case of failure.

TransactionValidationError

Transaction validation errors

Traits

AccountProvider

The account provider interface abstraction layer.

AddressMapping

Trait to be implemented for evm address mapping.

BlockHashMapping

A trait for getting a block hash by number.

EnsureAddressOrigin

EnsureCreateOrigin

FeeCalculator

Trait that outputs the current transaction gas price.

FixedGasWeightMappingAssociatedTypes

GasWeightMapping

A mapping function that converts Ethereum gas to Substrate weight

LinearCostPrecompile

OnChargeEVMTransaction

Handle withdrawing, refunding and depositing of transaction fees. Similar to OnChargeTransaction of pallet_transaction_payment

OnCreate

Precompile

One single precompile used by EVM engine.

PrecompileHandle

Handle provided to a precompile to interact with the EVM.

PrecompileSet

A set of precompiles.

Type Aliases

AccountIdOf

Utility alias for easy access to the AccountProvider::AccountId type from a given config.

BalanceOf

Type alias for currency balance.

CallInfo

CreateInfo

PrecompileResult