emulator

Documentation

Index

• Variables
• func GetDefaultSigner() types.Signer
• func GetSigner(cfg *Config) types.Signer
• type BlockView
  • func (bl *BlockView) DirectCall(call *types.DirectCall) (*types.Result, error)
  • func (bl *BlockView) RunTransaction(tx *gethTypes.Transaction) (*types.Result, error)
• type Config
  • func NewConfig(opts ...Option) *Config
• type Emulator
  • func NewEmulator(db types.Database) *Emulator
  • func (em *Emulator) NewBlockView(ctx types.BlockContext) (types.BlockView, error)
  • func (em *Emulator) NewReadOnlyBlockView(ctx types.BlockContext) (types.ReadOnlyBlockView, error)
• type Option
  • func WithBlockNumber(blockNumber *big.Int) Option
  • func WithBlockTime(time uint64) Option
  • func WithCoinbase(coinbase common.Address) Option
  • func WithDirectCallBaseGasUsage(gas uint64) Option
  • func WithGasLimit(gasLimit uint64) Option
  • func WithGasPrice(gasPrice *big.Int) Option
  • func WithGetBlockHashFunction(getHash vm.GetHashFunc) Option
  • func WithMainnetChainID() Option
  • func WithOrigin(origin common.Address) Option
  • func WithTestnetChainID() Option
• type ReadOnlyBlockView
  • func (bv *ReadOnlyBlockView) BalanceOf(address types.Address) (*big.Int, error)
  • func (bv *ReadOnlyBlockView) CodeOf(address types.Address) (types.Code, error)
  • func (bv *ReadOnlyBlockView) NonceOf(address types.Address) (uint64, error)

Variables

var (
	FlowEVMTestnetChainID = big.NewInt(666)
	FlowEVMMainnetChainID = big.NewInt(777)
	BlockLevelGasLimit    = uint64(math.MaxUint64)
)

var DefaultChainConfig = &params.ChainConfig{
	ChainID: FlowEVMTestnetChainID,

	HomesteadBlock:      big.NewInt(0),
	DAOForkBlock:        big.NewInt(0),
	DAOForkSupport:      false,
	EIP150Block:         big.NewInt(0),
	EIP155Block:         big.NewInt(0),
	EIP158Block:         big.NewInt(0),
	ByzantiumBlock:      big.NewInt(0),
	ConstantinopleBlock: big.NewInt(0),
	PetersburgBlock:     big.NewInt(0),
	IstanbulBlock:       big.NewInt(0),
	BerlinBlock:         big.NewInt(0),
	LondonBlock:         big.NewInt(0),
	MuirGlacierBlock:    big.NewInt(0),

	ShanghaiTime: &zero,
	CancunTime:   &zero,
	PragueTime:   &zero,
}

DefaultChainConfig is the default chain config which considers majority of EVM upgrades (e.g. Shanghai update) already been applied this has done through setting the height of these changes to zero nad setting the time for some other changes to zero For the future changes of EVM, we need to update the EVM go mod version and set a proper height for the specific release based on the Flow EVM heights so it could gets activated at a desired time.

Functions

func GetDefaultSigner

func GetDefaultSigner() types.Signer

GetDefaultSigner returns a signer which is compatible with the default config

func GetSigner

func GetSigner(cfg *Config) types.Signer

GetSigner returns a evm signer object that is compatible with the given config

Despite its misleading name, signer encapsulates transaction signature validation functionality and does not provide actual signing functionality. we kept the same name to be consistent with EVM naming.

Types

type BlockView

type BlockView struct {
	// contains filtered or unexported fields
}

BlockView allows mutation of the evm state as part of a block

TODO: allow multiple calls per block view TODO: add block level commit (separation of trie commit to storage)

func (*BlockView) DirectCall

func (bl *BlockView) DirectCall(call *types.DirectCall) (*types.Result, error)

DirectCall executes a direct call

func (*BlockView) RunTransaction

func (bl *BlockView) RunTransaction(
	tx *gethTypes.Transaction,
) (*types.Result, error)

RunTransaction runs an evm transaction

type Config

type Config struct {
	// Chain Config
	ChainConfig *params.ChainConfig
	// EVM config
	EVMConfig vm.Config
	// block context
	BlockContext *vm.BlockContext
	// transaction context
	TxContext *vm.TxContext
	// base unit of gas for direct calls
	DirectCallBaseGasUsage uint64
}

Config sets the required parameters

func NewConfig

func NewConfig(opts ...Option) *Config

NewConfig initializes a new config

type Emulator

type Emulator struct {
	Database types.Database
}

Emulator handles operations against evm runtime

func NewEmulator

func NewEmulator(
	db types.Database,
) *Emulator

NewEmulator constructs a new EVM Emulator

func (*Emulator) NewBlockView

func (em *Emulator) NewBlockView(ctx types.BlockContext) (types.BlockView, error)

NewBlockView constructs a new block view (mutable)

func (*Emulator) NewReadOnlyBlockView

func (em *Emulator) NewReadOnlyBlockView(ctx types.BlockContext) (types.ReadOnlyBlockView, error)

NewReadOnlyBlockView constructs a new readonly block view

type Option

type Option func(*Config) *Config

func WithBlockNumber

func WithBlockNumber(blockNumber *big.Int) Option

WithBlockNumber sets the block height in the block context

func WithBlockTime

func WithBlockTime(time uint64) Option

WithBlockTime sets the block time in the block context

func WithCoinbase

func WithCoinbase(coinbase common.Address) Option

WithCoinbase sets the coinbase of the block where the fees are collected in

func WithDirectCallBaseGasUsage

func WithDirectCallBaseGasUsage(gas uint64) Option

WithDirectCallBaseGasUsage sets the base direct call gas usage

func WithGasLimit

func WithGasLimit(gasLimit uint64) Option

WithGasLimit sets the gas limit of the transaction

func WithGasPrice

func WithGasPrice(gasPrice *big.Int) Option

WithGasPrice sets the gas price for the transaction (usually the one sets by the sender)

func WithGetBlockHashFunction

func WithGetBlockHashFunction(getHash vm.GetHashFunc) Option

WithGetBlockHashFunction sets the functionality to look up block hash by height

func WithMainnetChainID

func WithMainnetChainID() Option

WithMainnetChainID sets the chain ID to flow evm mainnet

func WithOrigin

func WithOrigin(origin common.Address) Option

WithOrigin sets the origin of the transaction (signer)

func WithTestnetChainID

func WithTestnetChainID() Option

WithMainnetChainID sets the chain ID to flow evm testnet

type ReadOnlyBlockView

type ReadOnlyBlockView struct {
	// contains filtered or unexported fields
}

ReadOnlyBlockView provides a read only view of a block could be used multiple times for queries

func (*ReadOnlyBlockView) BalanceOf

func (bv *ReadOnlyBlockView) BalanceOf(address types.Address) (*big.Int, error)

BalanceOf returns the balance of the given address

func (*ReadOnlyBlockView) CodeOf

func (bv *ReadOnlyBlockView) CodeOf(address types.Address) (types.Code, error)

CodeOf returns the code of the given address

func (*ReadOnlyBlockView) NonceOf

func (bv *ReadOnlyBlockView) NonceOf(address types.Address) (uint64, error)

NonceOf returns the nonce of the given address