tracing

Documentation

Index

• type BalanceChangeHook
• type BalanceChangeReason
  • func (i BalanceChangeReason) String() string
• type BlockEndHook
• type BlockEvent
• type BlockStartHook
• type BlockchainInitHook
• type CloseHook
• type CodeChangeHook
• type EnterHook
• type ExitHook
• type FaultHook
• type GasChangeHook
• type GasChangeReason
• type GenesisBlockHook
• type Hooks
• type LogHook
• type NonceChangeHook
• type OnSystemCallEndHook
• type OnSystemCallStartHook
• type OpContext
• type OpcodeHook
• type SkippedBlockHook
• type StateDB
• type StorageChangeHook
• type TxEndHook
• type TxStartHook
• type VMContext

Types

type BalanceChangeHook

type BalanceChangeHook = func(addr common.Address, prev, new *big.Int, reason BalanceChangeReason)

BalanceChangeHook is called when the balance of an account changes.

type BalanceChangeReason

type BalanceChangeReason byte

BalanceChangeReason is used to indicate the reason for a balance change, useful for tracing and reporting.

const (
	BalanceChangeUnspecified BalanceChangeReason = 0

	// Issuance
	// BalanceIncreaseRewardMineUncle is a reward for mining an uncle block.
	BalanceIncreaseRewardMineUncle BalanceChangeReason = 1
	// BalanceIncreaseRewardMineBlock is a reward for mining a block.
	BalanceIncreaseRewardMineBlock BalanceChangeReason = 2
	// BalanceIncreaseWithdrawal is ether withdrawn from the beacon chain.
	BalanceIncreaseWithdrawal BalanceChangeReason = 3
	// BalanceIncreaseGenesisBalance is ether allocated at the genesis block.
	BalanceIncreaseGenesisBalance BalanceChangeReason = 4

	// Transaction fees
	// BalanceIncreaseRewardTransactionFee is the transaction tip increasing block builder's balance.
	BalanceIncreaseRewardTransactionFee BalanceChangeReason = 5
	// BalanceDecreaseGasBuy is spent to purchase gas for execution a transaction.
	// Part of this gas will be burnt as per EIP-1559 rules.
	BalanceDecreaseGasBuy BalanceChangeReason = 6
	// BalanceIncreaseGasReturn is ether returned for unused gas at the end of execution.
	BalanceIncreaseGasReturn BalanceChangeReason = 7

	// DAO fork
	// BalanceIncreaseDaoContract is ether sent to the DAO refund contract.
	BalanceIncreaseDaoContract BalanceChangeReason = 8
	// BalanceDecreaseDaoAccount is ether taken from a DAO account to be moved to the refund contract.
	BalanceDecreaseDaoAccount BalanceChangeReason = 9

	// BalanceChangeTransfer is ether transferred via a call.
	// it is a decrease for the sender and an increase for the recipient.
	BalanceChangeTransfer BalanceChangeReason = 10
	// BalanceChangeTouchAccount is a transfer of zero value. It is only there to
	// touch-create an account.
	BalanceChangeTouchAccount BalanceChangeReason = 11

	// BalanceIncreaseSelfdestruct is added to the recipient as indicated by a selfdestructing account.
	BalanceIncreaseSelfdestruct BalanceChangeReason = 12
	// BalanceDecreaseSelfdestruct is deducted from a contract due to self-destruct.
	BalanceDecreaseSelfdestruct BalanceChangeReason = 13
	// BalanceDecreaseSelfdestructBurn is ether that is sent to an already self-destructed
	// account within the same tx (captured at end of tx).
	// Note it doesn't account for a self-destruct which appoints itself as recipient.
	BalanceDecreaseSelfdestructBurn BalanceChangeReason = 14
)

func (BalanceChangeReason) String

func (i BalanceChangeReason) String() string

type BlockEndHook

type BlockEndHook = func(err error)

BlockEndHook is called after executing a block.

type BlockEvent

type BlockEvent struct {
	Block     *types.Block
	TD        *big.Int
	Finalized *types.Header
	Safe      *types.Header
}

BlockEvent is emitted upon tracing an incoming block. It contains the block as well as consensus related information.

type BlockStartHook

type BlockStartHook = func(event BlockEvent)

BlockStartHook is called before executing `block`. `td` is the total difficulty prior to `block`.

type BlockchainInitHook

type BlockchainInitHook = func(chainConfig *params.ChainConfig)

BlockchainInitHook is called when the blockchain is initialized.

type CloseHook

type CloseHook = func()

CloseHook is called when the blockchain closes.

type CodeChangeHook

type CodeChangeHook = func(addr common.Address, prevCodeHash common.Hash, prevCode []byte, codeHash common.Hash, code []byte)

CodeChangeHook is called when the code of an account changes.

type EnterHook

type EnterHook = func(depth int, typ byte, from common.Address, to common.Address, input []byte, gas uint64, value *big.Int)

EnterHook is invoked when the processing of a message starts.

Take note that EnterHook, when in the context of a live tracer, can be invoked outside of the `OnTxStart` and `OnTxEnd` hooks when dealing with system calls, see OnSystemCallStartHook and OnSystemCallEndHook for more information.

type ExitHook

type ExitHook = func(depth int, output []byte, gasUsed uint64, err error, reverted bool)

ExitHook is invoked when the processing of a message ends. `revert` is true when there was an error during the execution. Exceptionally, before the homestead hardfork a contract creation that ran out of gas when attempting to persist the code to database did not count as a call failure and did not cause a revert of the call. This will be indicated by `reverted == false` and `err == ErrCodeStoreOutOfGas`.

Take note that ExitHook, when in the context of a live tracer, can be invoked outside of the `OnTxStart` and `OnTxEnd` hooks when dealing with system calls, see OnSystemCallStartHook and OnSystemCallEndHook for more information.

type FaultHook

type FaultHook = func(pc uint64, op byte, gas, cost uint64, scope OpContext, depth int, err error)

FaultHook is invoked when an error occurs during the execution of an opcode.

type GasChangeHook

type GasChangeHook = func(old, new uint64, reason GasChangeReason)

GasChangeHook is invoked when the gas changes.

type GasChangeReason

type GasChangeReason byte

GasChangeReason is used to indicate the reason for a gas change, useful for tracing and reporting.

There is essentially two types of gas changes, those that can be emitted once per transaction and those that can be emitted on a call basis, so possibly multiple times per transaction.

They can be recognized easily by their name, those that start with `GasChangeTx` are emitted once per transaction, while those that start with `GasChangeCall` are emitted on a call basis.

const (
	GasChangeUnspecified GasChangeReason = 0

	// GasChangeTxInitialBalance is the initial balance for the call which will be equal to the gasLimit of the call. There is only
	// one such gas change per transaction.
	GasChangeTxInitialBalance GasChangeReason = 1
	// GasChangeTxIntrinsicGas is the amount of gas that will be charged for the intrinsic cost of the transaction, there is
	// always exactly one of those per transaction.
	GasChangeTxIntrinsicGas GasChangeReason = 2
	// GasChangeTxRefunds is the sum of all refunds which happened during the tx execution (e.g. storage slot being cleared)
	// this generates an increase in gas. There is at most one of such gas change per transaction.
	GasChangeTxRefunds GasChangeReason = 3
	// GasChangeTxLeftOverReturned is the amount of gas left over at the end of transaction's execution that will be returned
	// to the chain. This change will always be a negative change as we "drain" left over gas towards 0. If there was no gas
	// left at the end of execution, no such even will be emitted. The returned gas's value in Wei is returned to caller.
	// There is at most one of such gas change per transaction.
	GasChangeTxLeftOverReturned GasChangeReason = 4

	// GasChangeCallInitialBalance is the initial balance for the call which will be equal to the gasLimit of the call. There is only
	// one such gas change per call.
	GasChangeCallInitialBalance GasChangeReason = 5
	// GasChangeCallLeftOverReturned is the amount of gas left over that will be returned to the caller, this change will always
	// be a negative change as we "drain" left over gas towards 0. If there was no gas left at the end of execution, no such even
	// will be emitted.
	GasChangeCallLeftOverReturned GasChangeReason = 6
	// GasChangeCallLeftOverRefunded is the amount of gas that will be refunded to the call after the child call execution it
	// executed completed. This value is always positive as we are giving gas back to the you, the left over gas of the child.
	// If there was no gas left to be refunded, no such even will be emitted.
	GasChangeCallLeftOverRefunded GasChangeReason = 7
	// GasChangeCallContractCreation is the amount of gas that will be burned for a CREATE.
	GasChangeCallContractCreation GasChangeReason = 8
	// GasChangeContractCreation is the amount of gas that will be burned for a CREATE2.
	GasChangeCallContractCreation2 GasChangeReason = 9
	// GasChangeCallCodeStorage is the amount of gas that will be charged for code storage.
	GasChangeCallCodeStorage GasChangeReason = 10
	// GasChangeCallOpCode is the amount of gas that will be charged for an opcode executed by the EVM, exact opcode that was
	// performed can be check by `OnOpcode` handling.
	GasChangeCallOpCode GasChangeReason = 11
	// GasChangeCallPrecompiledContract is the amount of gas that will be charged for a precompiled contract execution.
	GasChangeCallPrecompiledContract GasChangeReason = 12
	// GasChangeCallStorageColdAccess is the amount of gas that will be charged for a cold storage access as controlled by EIP2929 rules.
	GasChangeCallStorageColdAccess GasChangeReason = 13
	// GasChangeCallFailedExecution is the burning of the remaining gas when the execution failed without a revert.
	GasChangeCallFailedExecution GasChangeReason = 14
	// GasChangeWitnessContractInit is the amount charged for adding to the witness during the contract creation initialization step
	GasChangeWitnessContractInit GasChangeReason = 15
	// GasChangeWitnessContractCreation is the amount charged for adding to the witness during the contract creation finalization step
	GasChangeWitnessContractCreation GasChangeReason = 16
	// GasChangeWitnessCodeChunk is the amount charged for touching one or more contract code chunks
	GasChangeWitnessCodeChunk GasChangeReason = 17

	// GasChangeIgnored is a special value that can be used to indicate that the gas change should be ignored as
	// it will be "manually" tracked by a direct emit of the gas change event.
	GasChangeIgnored GasChangeReason = 0xFF
)

type GenesisBlockHook

type GenesisBlockHook = func(genesis *types.Block, alloc types.GenesisAlloc)

GenesisBlockHook is called when the genesis block is being processed.

type Hooks

type Hooks struct {
	// VM events
	OnTxStart   TxStartHook
	OnTxEnd     TxEndHook
	OnEnter     EnterHook
	OnExit      ExitHook
	OnOpcode    OpcodeHook
	OnFault     FaultHook
	OnGasChange GasChangeHook
	// Chain events
	OnBlockchainInit  BlockchainInitHook
	OnClose           CloseHook
	OnBlockStart      BlockStartHook
	OnBlockEnd        BlockEndHook
	OnSkippedBlock    SkippedBlockHook
	OnGenesisBlock    GenesisBlockHook
	OnSystemCallStart OnSystemCallStartHook
	OnSystemCallEnd   OnSystemCallEndHook
	// State events
	OnBalanceChange BalanceChangeHook
	OnNonceChange   NonceChangeHook
	OnCodeChange    CodeChangeHook
	OnStorageChange StorageChangeHook
	OnLog           LogHook
}

type LogHook

type LogHook = func(log *types.Log)

LogHook is called when a log is emitted.

type NonceChangeHook

type NonceChangeHook = func(addr common.Address, prev, new uint64)

NonceChangeHook is called when the nonce of an account changes.

type OnSystemCallEndHook

type OnSystemCallEndHook = func()

OnSystemCallEndHook is called when a system call has finished executing. Today, this hook is invoked when the EIP-4788 system call is about to be executed to set the beacon block root.

type OnSystemCallStartHook

type OnSystemCallStartHook = func()

OnSystemCallStartHook is called when a system call is about to be executed. Today, this hook is invoked when the EIP-4788 system call is about to be executed to set the beacon block root.

After this hook, the EVM call tracing will happened as usual so you will receive a `OnEnter/OnExit` as well as state hooks between this hook and the `OnSystemCallEndHook`.

Note that system call happens outside normal transaction execution, so the `OnTxStart/OnTxEnd` hooks will not be invoked.

type OpContext

type OpContext interface {
	MemoryData() []byte
	StackData() []uint256.Int
	Caller() common.Address
	Address() common.Address
	CallValue() *uint256.Int
	CallInput() []byte
}

OpContext provides the context at which the opcode is being executed in, including the memory, stack and various contract-level information.

type OpcodeHook

type OpcodeHook = func(pc uint64, op byte, gas, cost uint64, scope OpContext, rData []byte, depth int, err error)

OpcodeHook is invoked just prior to the execution of an opcode.

type SkippedBlockHook

type SkippedBlockHook = func(event BlockEvent)

SkippedBlockHook indicates a block was skipped during processing due to it being known previously. This can happen e.g. when recovering from a crash.

type StateDB

type StateDB interface {
	GetBalance(common.Address) *uint256.Int
	GetNonce(common.Address) uint64
	GetCode(common.Address) []byte
	GetState(common.Address, common.Hash) common.Hash
	Exist(common.Address) bool
	GetRefund() uint64
}

StateDB gives tracers access to the whole state.

type StorageChangeHook

type StorageChangeHook = func(addr common.Address, slot common.Hash, prev, new common.Hash)

StorageChangeHook is called when the storage of an account changes.

type TxEndHook

type TxEndHook = func(receipt *types.Receipt, err error)

TxEndHook is called after the execution of a transaction ends.

type TxStartHook

type TxStartHook = func(vm *VMContext, tx *types.Transaction, from common.Address)

TxStartHook is called before the execution of a transaction starts. Call simulations don't come with a valid signature. `from` field to be used for address of the caller.

type VMContext

type VMContext struct {
	Coinbase    common.Address
	BlockNumber *big.Int
	Time        uint64
	Random      *common.Hash
	// Effective tx gas price
	GasPrice    *big.Int
	ChainConfig *params.ChainConfig
	StateDB     StateDB
}

VMContext provides the context for the EVM execution.