utils: remove utils package in favor of new swap package

swap/fees.go

@@ -0,0 +1,46 @@
+package swap
+
+import (
+	"errors"
+
+	"github.com/btcsuite/btcd/chaincfg"
+	"github.com/btcsuite/btcutil"
+	"github.com/lightningnetwork/lnd/zpay32"
+)
+
+const (
+	// FeeRateTotalParts defines the granularity of the fee rate.
+	// Throughout the codebase, we'll use fix based arithmetic to compute
+	// fees.
+	FeeRateTotalParts = 1e6
+)
+
+// CalcFee returns the swap fee for a given swap amount.
+func CalcFee(amount, feeBase btcutil.Amount, feeRate int64) btcutil.Amount {
+	return feeBase + amount*btcutil.Amount(feeRate)/
+		btcutil.Amount(FeeRateTotalParts)
+}
+
+// FeeRateAsPercentage converts a feerate to a percentage.
+func FeeRateAsPercentage(feeRate int64) float64 {
+	return float64(feeRate) / (FeeRateTotalParts / 100)
+}
+
+// GetInvoiceAmt gets the invoice amount. It requires an amount to be
+// specified.
+func GetInvoiceAmt(params *chaincfg.Params,
+	payReq string) (btcutil.Amount, error) {
+
+	swapPayReq, err := zpay32.Decode(
+		payReq, params,
+	)
+	if err != nil {
+		return 0, err
+	}
+
+	if swapPayReq.MilliSat == nil {
+		return 0, errors.New("no amount in invoice")
+	}
+
+	return swapPayReq.MilliSat.ToSatoshis(), nil
+}

swap/htlc.go

@@ -1,4 +1,4 @@
-package utils
+package swap
 
 import (
 	"bytes"

swap/keychain.go

@@ -0,0 +1,9 @@
+package swap
+
+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)
+)

swap/net.go

@@ -0,0 +1,27 @@
+package swap
+
+import (
+	"errors"
+
+	"github.com/btcsuite/btcd/chaincfg"
+)
+
+// ChainParamsFromNetwork returns chain parameters based on a network name.
+func ChainParamsFromNetwork(network string) (*chaincfg.Params, error) {
+	switch network {
+	case "mainnet":
+		return &chaincfg.MainNetParams, nil
+
+	case "testnet":
+		return &chaincfg.TestNet3Params, nil
+
+	case "regtest":
+		return &chaincfg.RegressionNetParams, nil
+
+	case "simnet":
+		return &chaincfg.SimNetParams, nil
+
+	default:
+		return nil, errors.New("unknown network")
+	}
+}

swap/tx.go

@@ -0,0 +1,64 @@
+package swap
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+
+	"github.com/btcsuite/btcd/wire"
+	"github.com/btcsuite/btcutil"
+)
+
+// EncodeTx encodes a tx to raw bytes.
+func EncodeTx(tx *wire.MsgTx) ([]byte, error) {
+	var buffer bytes.Buffer
+	err := tx.BtcEncode(&buffer, 0, wire.WitnessEncoding)
+	if err != nil {
+		return nil, err
+	}
+	rawTx := buffer.Bytes()
+
+	return rawTx, nil
+}
+
+// DecodeTx decodes raw tx bytes.
+func DecodeTx(rawTx []byte) (*wire.MsgTx, error) {
+	tx := wire.MsgTx{}
+	r := bytes.NewReader(rawTx)
+	err := tx.BtcDecode(r, 0, wire.WitnessEncoding)
+	if err != nil {
+		return nil, err
+	}
+
+	return &tx, nil
+}
+
+// GetScriptOutput locates the given script in the outputs of a transaction and
+// returns its outpoint and value.
+func GetScriptOutput(htlcTx *wire.MsgTx, scriptHash []byte) (
+	*wire.OutPoint, btcutil.Amount, error) {
+
+	for idx, output := range htlcTx.TxOut {
+		if bytes.Equal(output.PkScript, scriptHash) {
+			return &wire.OutPoint{
+				Hash:  htlcTx.TxHash(),
+				Index: uint32(idx),
+			}, btcutil.Amount(output.Value), nil
+		}
+	}
+
+	return nil, 0, fmt.Errorf("cannot determine outpoint")
+}
+
+// GetTxInputByOutpoint returns a tx input based on a given input outpoint.
+func GetTxInputByOutpoint(tx *wire.MsgTx, input *wire.OutPoint) (
+	*wire.TxIn, error) {
+
+	for _, in := range tx.TxIn {
+		if in.PreviousOutPoint == *input {
+			return in, nil
+		}
+	}
+
+	return nil, errors.New("input not found")
+}

utils/config.go

@@ -1,9 +0,0 @@
-package utils
-
-var (
-	// SwapKeyFamily is the key family used to generate keys that allow
-	// spending of the htlc.
-	//
-	// TODO(joost): decide on actual value
-	SwapKeyFamily = int32(99)
-)

utils/swaplog.go

@@ -1,41 +0,0 @@
-package utils
-
-import (
-	"fmt"
-	"github.com/btcsuite/btclog"
-	"github.com/lightningnetwork/lnd/lntypes"
-)
-
-// SwapLog logs with a short swap hash prefix.
-type SwapLog struct {
-	Logger btclog.Logger
-	Hash   lntypes.Hash
-}
-
-// Infof formats message according to format specifier and writes to
-// log with LevelInfo.
-func (s *SwapLog) Infof(format string, params ...interface{}) {
-	s.Logger.Infof(
-		fmt.Sprintf("%v %s", ShortHash(&s.Hash), format),
-		params...,
-	)
-}
-
-// Warnf formats message according to format specifier and writes to
-// to log with LevelError.
-func (s *SwapLog) Warnf(format string, params ...interface{}) {
-	s.Logger.Warnf(
-		fmt.Sprintf("%v %s", ShortHash(&s.Hash), format),
-		params...,
-	)
-}
-
-// Errorf formats message according to format specifier and writes to
-// to log with LevelError.
-func (s *SwapLog) Errorf(format string, params ...interface{}) {
-	s.Logger.Errorf(
-		fmt.Sprintf("%v %s", ShortHash(&s.Hash), format),
-		params...,
-	)
-
-}

utils/utils.go

@@ -1,123 +0,0 @@
-package utils
-
-import (
-	"bytes"
-	"errors"
-	"fmt"
-	"os"
-
-	"github.com/btcsuite/btcd/chaincfg"
-	"github.com/btcsuite/btcutil"
-	"github.com/lightningnetwork/lnd/lntypes"
-	"github.com/lightningnetwork/lnd/zpay32"
-
-	"github.com/btcsuite/btcd/wire"
-)
-
-const (
-	// FeeRateTotalParts defines the granularity of the fee rate.
-	FeeRateTotalParts = 1e6
-)
-
-// ShortHash returns a shortened version of the hash suitable for use in
-// logging.
-func ShortHash(hash *lntypes.Hash) string {
-	return hash.String()[:6]
-}
-
-// EncodeTx encodes a tx to raw bytes.
-func EncodeTx(tx *wire.MsgTx) ([]byte, error) {
-	var buffer bytes.Buffer
-	err := tx.BtcEncode(&buffer, 0, wire.WitnessEncoding)
-	if err != nil {
-		return nil, err
-	}
-	rawTx := buffer.Bytes()
-
-	return rawTx, nil
-}
-
-// DecodeTx decodes raw tx bytes.
-func DecodeTx(rawTx []byte) (*wire.MsgTx, error) {
-	tx := wire.MsgTx{}
-	r := bytes.NewReader(rawTx)
-	err := tx.BtcDecode(r, 0, wire.WitnessEncoding)
-	if err != nil {
-		return nil, err
-	}
-
-	return &tx, nil
-}
-
-// GetInvoiceAmt gets the invoice amount. It requires an amount to be specified.
-func GetInvoiceAmt(params *chaincfg.Params,
-	payReq string) (btcutil.Amount, error) {
-
-	swapPayReq, err := zpay32.Decode(
-		payReq, params,
-	)
-	if err != nil {
-		return 0, err
-	}
-
-	if swapPayReq.MilliSat == nil {
-		return 0, errors.New("no amount in invoice")
-	}
-
-	return swapPayReq.MilliSat.ToSatoshis(), nil
-}
-
-// FileExists returns true if the file exists, and false otherwise.
-func FileExists(path string) bool {
-	if _, err := os.Stat(path); err != nil {
-		if os.IsNotExist(err) {
-			return false
-		}
-	}
-
-	return true
-}
-
-// ChainParamsFromNetwork returns chain parameters based on a network name.
-func ChainParamsFromNetwork(network string) (*chaincfg.Params, error) {
-	switch network {
-	case "mainnet":
-		return &chaincfg.MainNetParams, nil
-	case "testnet":
-		return &chaincfg.TestNet3Params, nil
-	case "regtest":
-		return &chaincfg.RegressionNetParams, nil
-	case "simnet":
-		return &chaincfg.SimNetParams, nil
-	default:
-		return nil, errors.New("unknown network")
-	}
-}
-
-// GetScriptOutput locates the given script in the outputs of a transaction and
-// returns its outpoint and value.
-func GetScriptOutput(htlcTx *wire.MsgTx, scriptHash []byte) (
-	*wire.OutPoint, btcutil.Amount, error) {
-
-	for idx, output := range htlcTx.TxOut {
-		if bytes.Equal(output.PkScript, scriptHash) {
-			return &wire.OutPoint{
-				Hash:  htlcTx.TxHash(),
-				Index: uint32(idx),
-			}, btcutil.Amount(output.Value), nil
-		}
-	}
-
-	return nil, 0, fmt.Errorf("cannot determine outpoint")
-}
-
-// CalcFee returns the swap fee for a given swap amount.
-func CalcFee(amount, feeBase btcutil.Amount, feeRate int64) btcutil.Amount {
-	return feeBase + amount*btcutil.Amount(feeRate)/
-		btcutil.Amount(FeeRateTotalParts)
-}
-
-// FeeRateAsPercentage converts a feerate to a percentage.
-func FeeRateAsPercentage(feeRate int64) float64 {
-	return float64(feeRate) / (FeeRateTotalParts / 100)
-}