swap

Documentation

Index

• Constants
• Variables
• func CalcFee(amount, feeBase btcutil.Amount, feeRate int64) btcutil.Amount
• func ChainParamsFromNetwork(network string) (*chaincfg.Params, error)
• func DecodeInvoice(params *chaincfg.Params, payReq string) (lntypes.Hash, btcutil.Amount, error)
• func DecodeTx(rawTx []byte) (*wire.MsgTx, error)
• func EncodeTx(tx *wire.MsgTx) ([]byte, error)
• func FeeRateAsPercentage(feeRate int64) float64
• func GetScriptOutput(htlcTx *wire.MsgTx, scriptHash []byte) (*wire.OutPoint, btcutil.Amount, error)
• func GetTxInputByOutpoint(tx *wire.MsgTx, input *wire.OutPoint) (*wire.TxIn, error)
• func ShortHash(hash *lntypes.Hash) string
• type Htlc
  • func NewHtlc(cltvExpiry int32, senderKey, receiverKey [33]byte, hash lntypes.Hash, ...) (*Htlc, error)
  • func (h *Htlc) AddSuccessToEstimator(estimator *input.TxWeightEstimator)
  • func (h *Htlc) AddTimeoutToEstimator(estimator *input.TxWeightEstimator)
  • func (h *Htlc) GenSuccessWitness(receiverSig []byte, preimage lntypes.Preimage) (wire.TxWitness, error)
  • func (h *Htlc) GenTimeoutWitness(senderSig []byte) (wire.TxWitness, error)
  • func (h *Htlc) IsSuccessWitness(witness wire.TxWitness) bool
• type HtlcOutputType
• type PrefixLog
  • func (s *PrefixLog) Errorf(format string, params ...interface{})
  • func (s *PrefixLog) Infof(format string, params ...interface{})
  • func (s *PrefixLog) Warnf(format string, params ...interface{})
• type Type
  • func (t Type) String() string

Constants

const (
	// FeeRateTotalParts defines the granularity of the fee rate.
	// Throughout the codebase, we'll use fix based arithmetic to compute
	// fees.
	FeeRateTotalParts = 1e6
)

Variables

var (
	// KeyFamily is the key family used to generate keys that allow
	// spending of the htlc.
	//
	// TODO(joost): decide on actual value
	KeyFamily = int32(99)
)

var (

	// QuoteHtlc is a template script just used for fee estimation. It uses
	// the maximum value for cltv expiry to get the maximum (worst case)
	// script size.
	QuoteHtlc, _ = NewHtlc(
		^int32(0), quoteKey, quoteKey, quoteHash, HtlcP2WSH,
		&chaincfg.MainNetParams,
	)
)

Functions

func CalcFee

func CalcFee(amount, feeBase btcutil.Amount, feeRate int64) btcutil.Amount

CalcFee returns the swap fee for a given swap amount.

func ChainParamsFromNetwork

func ChainParamsFromNetwork(network string) (*chaincfg.Params, error)

ChainParamsFromNetwork returns chain parameters based on a network name.

func DecodeInvoice

func DecodeInvoice(params *chaincfg.Params,
	payReq string) (lntypes.Hash, btcutil.Amount, error)

DecodeInvoice gets the hash and the amount of an invoice. It requires an amount to be specified.

func DecodeTx

func DecodeTx(rawTx []byte) (*wire.MsgTx, error)

DecodeTx decodes raw tx bytes.

func EncodeTx

func EncodeTx(tx *wire.MsgTx) ([]byte, error)

EncodeTx encodes a tx to raw bytes.

func FeeRateAsPercentage

func FeeRateAsPercentage(feeRate int64) float64

FeeRateAsPercentage converts a feerate to a percentage.

func GetScriptOutput

func GetScriptOutput(htlcTx *wire.MsgTx, scriptHash []byte) (
	*wire.OutPoint, btcutil.Amount, error)

GetScriptOutput locates the given script in the outputs of a transaction and returns its outpoint and value.

func GetTxInputByOutpoint

func GetTxInputByOutpoint(tx *wire.MsgTx, input *wire.OutPoint) (
	*wire.TxIn, error)

GetTxInputByOutpoint returns a tx input based on a given input outpoint.

func ShortHash

func ShortHash(hash *lntypes.Hash) string

ShortHash returns a shortened version of the hash suitable for use in logging.

Types

type Htlc

type Htlc struct {
	Script      []byte
	PkScript    []byte
	Hash        lntypes.Hash
	OutputType  HtlcOutputType
	ChainParams *chaincfg.Params
	Address     btcutil.Address
	SigScript   []byte
}

Htlc contains relevant htlc information from the receiver perspective.

func NewHtlc

func NewHtlc(cltvExpiry int32, senderKey, receiverKey [33]byte,
	hash lntypes.Hash, outputType HtlcOutputType,
	chainParams *chaincfg.Params) (*Htlc, error)

NewHtlc returns a new instance.

func (*Htlc) AddSuccessToEstimator

func (h *Htlc) AddSuccessToEstimator(estimator *input.TxWeightEstimator)

AddSuccessToEstimator adds a successful spend to a weight estimator.

func (*Htlc) AddTimeoutToEstimator

func (h *Htlc) AddTimeoutToEstimator(estimator *input.TxWeightEstimator)

AddTimeoutToEstimator adds a timeout spend to a weight estimator.

func (*Htlc) GenSuccessWitness

func (h *Htlc) GenSuccessWitness(receiverSig []byte,
	preimage lntypes.Preimage) (wire.TxWitness, error)

GenSuccessWitness returns the success script to spend this htlc with the preimage.

func (*Htlc) GenTimeoutWitness

func (h *Htlc) GenTimeoutWitness(senderSig []byte) (wire.TxWitness, error)

GenTimeoutWitness returns the timeout script to spend this htlc after timeout.

func (*Htlc) IsSuccessWitness

func (h *Htlc) IsSuccessWitness(witness wire.TxWitness) bool

IsSuccessWitness checks whether the given stack is valid for redeeming the htlc.

type HtlcOutputType

type HtlcOutputType uint8

HtlcOutputType defines the output type of the htlc that is published.

const (
	// HtlcP2WSH is a pay-to-witness-script-hash output (segwit only)
	HtlcP2WSH HtlcOutputType = iota

	// HtlcNP2WSH is a nested pay-to-witness-script-hash output that can be
	// paid to be legacy wallets.
	HtlcNP2WSH
)

type PrefixLog

type PrefixLog struct {
	// Logger is the underlying based logger.
	Logger btclog.Logger

	// Hash is the hash the identifies the target swap.
	Hash lntypes.Hash
}

PrefixLog logs with a short swap hash prefix.

func (*PrefixLog) Errorf

func (s *PrefixLog) Errorf(format string, params ...interface{})

Errorf formats message according to format specifier and writes to to log with LevelError.

func (*PrefixLog) Infof

func (s *PrefixLog) Infof(format string, params ...interface{})

Infof formats message according to format specifier and writes to log with LevelInfo.

func (*PrefixLog) Warnf

func (s *PrefixLog) Warnf(format string, params ...interface{})

Warnf formats message according to format specifier and writes to to log with LevelError.

type Type

type Type uint8

Type indicates the type of swap.

const (
	// TypeIn is a loop in swap.
	TypeIn Type = iota

	// TypeOut is a loop out swap.
	TypeOut
)

func (Type) String

func (t Type) String() string