[#465] settlement: Use unified details format for all asset transfers

Unified format uses transfer type as the first byte
and extra details next. List of transfer types used in
contracts defined in `details.go`. It includes:
- audit settlement,
- basic income collection,
- basic income distribution.

Signed-off-by: Alex Vanin <alexey@nspcc.ru>

pkg/innerring/innerring.go

@@ -387,13 +387,13 @@ func New(ctx context.Context, log *zap.Logger, cfg *viper.Viper) (*Server, error
 
 	// create settlement processor dependencies
 	settlementDeps := &settlementDeps{
+		globalConfig:  globalConfig,
 		log:           server.log,
 		cnrSrc:        cnrClient,
 		auditClient:   server.auditClient,
 		nmSrc:         nmClient,
 		clientCache:   clientCache,
 		balanceClient: balClient,
-		cfg:           globalConfig,
 	}
 
 	auditCalcDeps := &auditSettlementDeps{

pkg/innerring/processors/settlement/audit/calculate.go

@@ -65,8 +65,9 @@ func (c *Calculator) Calculate(p *CalculatePrm) {
 	log.Info("calculate audit settlements")
 
 	log.Debug("getting results for the previous epoch")
+	prevEpoch := p.Epoch - 1
 
-	auditResults, err := c.prm.ResultStorage.AuditResultsForEpoch(p.Epoch - 1)
+	auditResults, err := c.prm.ResultStorage.AuditResultsForEpoch(prevEpoch)
 	if err != nil {
 		log.Error("could not collect audit results")
 		return
@@ -99,7 +100,7 @@ func (c *Calculator) Calculate(p *CalculatePrm) {
 
 	log.Debug("processing transfers")
 
-	common.TransferAssets(c.prm.Exchanger, table)
+	common.TransferAssets(c.prm.Exchanger, table, common.AuditSettlementDetails(prevEpoch))
 }
 
 func (c *Calculator) processResult(ctx *singleResultCtx) {

pkg/innerring/processors/settlement/basic/collect.go

@@ -70,7 +70,7 @@ func (inc *IncomeSettlementContext) Collect() {
 		})
 	}
 
-	common.TransferAssets(inc.exchange, txTable)
+	common.TransferAssets(inc.exchange, txTable, common.BasicIncomeCollectionDetails(inc.epoch))
 }
 
 // avgEstimation returns estimation value for single container. Right now it

pkg/innerring/processors/settlement/basic/distribute.go

@@ -41,7 +41,7 @@ func (inc *IncomeSettlementContext) Distribute() {
 		})
 	})
 
-	common.TransferAssets(inc.exchange, txTable)
+	common.TransferAssets(inc.exchange, txTable, common.BasicIncomeDistributionDetails(inc.epoch))
 }
 
 func normalizedValue(n, total, limit *big.Int) *big.Int {

pkg/innerring/processors/settlement/common/details.go

@@ -0,0 +1,33 @@
+package common
+
+import (
+	"encoding/binary"
+)
+
+var (
+	auditPrefix                   = []byte{0x40}
+	basicIncomeCollectionPrefix   = []byte{0x41}
+	basicIncomeDistributionPrefix = []byte{0x42}
+)
+
+func AuditSettlementDetails(epoch uint64) []byte {
+	return details(auditPrefix, epoch)
+}
+
+func BasicIncomeCollectionDetails(epoch uint64) []byte {
+	return details(basicIncomeCollectionPrefix, epoch)
+}
+
+func BasicIncomeDistributionDetails(epoch uint64) []byte {
+	return details(basicIncomeDistributionPrefix, epoch)
+}
+
+func details(prefix []byte, epoch uint64) []byte {
+	prefixLen := len(prefix)
+	buf := make([]byte, prefixLen+8)
+
+	copy(buf, prefix)
+	binary.LittleEndian.PutUint64(buf[prefixLen:], epoch)
+
+	return buf
+}

pkg/innerring/processors/settlement/common/details_test.go

@@ -0,0 +1,28 @@
+package common
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestAuditSettlementDetails(t *testing.T) {
+	var n uint64 = 1994 // 0x7CA
+	exp := []byte{0x40, 0xCA, 0x07, 0, 0, 0, 0, 0, 0}
+	got := AuditSettlementDetails(n)
+	require.Equal(t, exp, got)
+}
+
+func TestBasicIncomeCollectionDetails(t *testing.T) {
+	var n uint64 = 1994 // 0x7CA
+	exp := []byte{0x41, 0xCA, 0x07, 0, 0, 0, 0, 0, 0}
+	got := BasicIncomeCollectionDetails(n)
+	require.Equal(t, exp, got)
+}
+
+func TestBasicIncomeDistributionDetails(t *testing.T) {
+	var n uint64 = 1994 // 0x7CA
+	exp := []byte{0x42, 0xCA, 0x07, 0, 0, 0, 0, 0, 0}
+	got := BasicIncomeDistributionDetails(n)
+	require.Equal(t, exp, got)
+}

pkg/innerring/processors/settlement/common/types.go

@@ -50,5 +50,5 @@ type Exchanger interface {
 	// Must transfer amount of GASe-12 from sender to recipient.
 	//
 	// Amount must be positive.
-	Transfer(sender, recipient *owner.ID, amount *big.Int)
+	Transfer(sender, recipient *owner.ID, amount *big.Int, details []byte)
 }

pkg/innerring/processors/settlement/common/util.go

@@ -56,7 +56,7 @@ func (t *TransferTable) Iterate(f func(*TransferTx)) {
 	}
 }
 
-func TransferAssets(e Exchanger, t *TransferTable) {
+func TransferAssets(e Exchanger, t *TransferTable, details []byte) {
 	t.Iterate(func(tx *TransferTx) {
 		sign := tx.Amount.Sign()
 		if sign == 0 {
@@ -68,6 +68,6 @@ func TransferAssets(e Exchanger, t *TransferTable) {
 			tx.Amount.Neg(tx.Amount)
 		}
 
-		e.Transfer(tx.From, tx.To, tx.Amount)
+		e.Transfer(tx.From, tx.To, tx.Amount, details)
 	})
 }

pkg/innerring/settlement.go

@@ -32,6 +32,8 @@ type globalConfig interface {
 }
 
 type settlementDeps struct {
+	globalConfig
+
 	log *logger.Logger
 
 	cnrSrc container.Source
@@ -43,8 +45,6 @@ type settlementDeps struct {
 	clientCache *ClientCache
 
 	balanceClient *balanceClient.Wrapper
-
-	cfg globalConfig
 }
 
 type auditSettlementDeps struct {
@@ -191,16 +191,12 @@ func (s settlementDeps) ResolveKey(ni common.NodeInfo) (*owner.ID, error) {
 	return id, nil
 }
 
-var (
+func (s settlementDeps) Transfer(sender, recipient *owner.ID, amount *big.Int, details []byte) {
-	transferAuditDetails    = []byte("settlement-audit")
-	basicIncomeAuditDetails = []byte("settlement-basic-income")
-)
-
-func (s settlementDeps) transfer(sender, recipient *owner.ID, amount *big.Int, details []byte) {
 	log := s.log.With(
 		zap.Stringer("sender", sender),
 		zap.Stringer("recipient", recipient),
 		zap.Stringer("amount (GASe-12)", amount),
+		zap.String("details", hex.EncodeToString(details)),
 	)
 
 	if !amount.IsInt64() {
@@ -225,20 +221,8 @@ func (s settlementDeps) transfer(sender, recipient *owner.ID, amount *big.Int, d
 	log.Debug("transfer transaction for audit was successfully sent")
 }
 
-func (a auditSettlementDeps) Transfer(sender, recipient *owner.ID, amount *big.Int) {
-	a.transfer(sender, recipient, amount, transferAuditDetails)
-}
-
-func (a auditSettlementDeps) AuditFee() (uint64, error) {
-	return a.cfg.AuditFee()
-}
-
-func (b basicIncomeSettlementDeps) Transfer(sender, recipient *owner.ID, amount *big.Int) {
-	b.transfer(sender, recipient, amount, basicIncomeAuditDetails)
-}
-
 func (b basicIncomeSettlementDeps) BasicRate() (uint64, error) {
-	return b.cfg.BasicIncomeRate()
+	return b.BasicIncomeRate()
 }
 
 func (b basicIncomeSettlementDeps) Estimations(epoch uint64) ([]*wrapper.Estimations, error) {