contract

Documentation

Overview

Defines the interface for the configuration and execution of a precompile contract

Index

• Constants
• func CalculateFunctionSelector(functionSignature string) []byte
• func DeductGas(suppliedGas uint64, requiredGas uint64) (uint64, error)
• func NewMockAccessibleState(state StateDB, blockContext *mockBlockContext, snowContext *snow.Context) *mockAccessibleState
• func NewMockBlockContext(blockNumber *big.Int, timestamp uint64) *mockBlockContext
• func NewMockChainState(feeConfig commontype.FeeConfig, allowedFeeRecipients bool) *mockChainState
• func PackOrderedHashes(dst []byte, hashes []common.Hash) error
• func PackOrderedHashesWithSelector(dst []byte, functionSelector []byte, hashes []common.Hash) error
• func PackedHash(packed []byte, index int) []byte
• func ParseABI(rawABI string) abi.ABI
• type AccessibleState
• type BlockContext
• type ChainConfig
• type Configurator
• type RunStatefulPrecompileFunc
• type StateDB
• type StatefulPrecompileFunction
  • func NewStatefulPrecompileFunction(selector []byte, execute RunStatefulPrecompileFunc) *StatefulPrecompileFunction
• type StatefulPrecompiledContract
  • func NewStatefulPrecompileContract(fallback RunStatefulPrecompileFunc, functions []*StatefulPrecompileFunction) (StatefulPrecompiledContract, error)

Constants

const (
	WriteGasCostPerSlot = 20_000
	ReadGasCostPerSlot  = 5_000
)

Gas costs for stateful precompiles

const (
	SelectorLen = 4
)

Functions

func CalculateFunctionSelector

func CalculateFunctionSelector(functionSignature string) []byte

CalculateFunctionSelector returns the 4 byte function selector that results from [functionSignature] Ex. the function setBalance(addr address, balance uint256) should be passed in as the string: "setBalance(address,uint256)" TODO: remove this after moving to ABI based function selectors.

func DeductGas

func DeductGas(suppliedGas uint64, requiredGas uint64) (uint64, error)

DeductGas checks if [suppliedGas] is sufficient against [requiredGas] and deducts [requiredGas] from [suppliedGas].

func NewMockAccessibleState

func NewMockAccessibleState(state StateDB, blockContext *mockBlockContext, snowContext *snow.Context) *mockAccessibleState

func NewMockBlockContext

func NewMockBlockContext(blockNumber *big.Int, timestamp uint64) *mockBlockContext

func NewMockChainState

func NewMockChainState(feeConfig commontype.FeeConfig, allowedFeeRecipients bool) *mockChainState

func PackOrderedHashes

func PackOrderedHashes(dst []byte, hashes []common.Hash) error

PackOrderedHashes packs the ordered list of [hashes] into the [dst] byte buffer. assumes that [dst] has sufficient space to pack [hashes] or else this function will panic.

func PackOrderedHashesWithSelector

func PackOrderedHashesWithSelector(dst []byte, functionSelector []byte, hashes []common.Hash) error

PackOrderedHashesWithSelector packs the function selector and ordered list of hashes into [dst] byte slice. assumes that [dst] has sufficient room for [functionSelector] and [hashes].

func PackedHash

func PackedHash(packed []byte, index int) []byte

PackedHash returns packed the byte slice with common.HashLength from [packed] at the given [index]. Assumes that [packed] is composed entirely of packed 32 byte segments.

func ParseABI

func ParseABI(rawABI string) abi.ABI

ParseABI parses the given ABI string and returns the parsed ABI. If the ABI is invalid, it panics.

Types

type AccessibleState

type AccessibleState interface {
	GetStateDB() StateDB
	GetBlockContext() BlockContext
	GetSnowContext() *snow.Context
}

AccessibleState defines the interface exposed to stateful precompile contracts

type BlockContext

type BlockContext interface {
	Number() *big.Int
	Timestamp() uint64
}

BlockContext defines an interface that provides information to a stateful precompile about the current block. The BlockContext may be provided during both precompile activation and execution.

type ChainConfig

type ChainConfig interface {
	// GetFeeConfig returns the original FeeConfig that was set in the genesis.
	GetFeeConfig() commontype.FeeConfig
	// AllowedFeeRecipients returns true if fee recipients are allowed in the genesis.
	AllowedFeeRecipients() bool
}

ChainContext defines an interface that provides information to a stateful precompile about the chain configuration. The precompile can access this information to initialize its state.

type Configurator

type Configurator interface {
	MakeConfig() precompileconfig.Config
	Configure(
		chainConfig ChainConfig,
		precompileconfig precompileconfig.Config,
		state StateDB,
		blockContext BlockContext,
	) error
}

type RunStatefulPrecompileFunc

type RunStatefulPrecompileFunc func(accessibleState AccessibleState, caller common.Address, addr common.Address, input []byte, suppliedGas uint64, readOnly bool) (ret []byte, remainingGas uint64, err error)

type StateDB

type StateDB interface {
	GetState(common.Address, common.Hash) common.Hash
	SetState(common.Address, common.Hash, common.Hash)

	SetNonce(common.Address, uint64)
	GetNonce(common.Address) uint64

	GetBalance(common.Address) *big.Int
	AddBalance(common.Address, *big.Int)

	CreateAccount(common.Address)
	Exist(common.Address) bool

	AddLog(addr common.Address, topics []common.Hash, data []byte, blockNumber uint64)
	GetLogData() [][]byte
	GetPredicateStorageSlots(address common.Address) ([]byte, bool)
	SetPredicateStorageSlots(address common.Address, predicate []byte)

	Suicide(common.Address) bool
	Finalise(deleteEmptyObjects bool)

	Snapshot() int
	RevertToSnapshot(int)
}

StateDB is the interface for accessing EVM state

type StatefulPrecompileFunction

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

StatefulPrecompileFunction defines a function implemented by a stateful precompile

func NewStatefulPrecompileFunction

func NewStatefulPrecompileFunction(selector []byte, execute RunStatefulPrecompileFunc) *StatefulPrecompileFunction

NewStatefulPrecompileFunction creates a stateful precompile function with the given arguments

type StatefulPrecompiledContract

type StatefulPrecompiledContract interface {
	// Run executes the precompiled contract.
	Run(accessibleState AccessibleState, caller common.Address, addr common.Address, input []byte, suppliedGas uint64, readOnly bool) (ret []byte, remainingGas uint64, err error)
}

StatefulPrecompiledContract is the interface for executing a precompiled contract

func NewStatefulPrecompileContract

func NewStatefulPrecompileContract(fallback RunStatefulPrecompileFunc, functions []*StatefulPrecompileFunction) (StatefulPrecompiledContract, error)

NewStatefulPrecompileContract generates new StatefulPrecompile using [functions] as the available functions and [fallback] as an optional fallback if there is no input data. Note: the selector of [fallback] will be ignored, so it is required to be left empty.