multi: introduce new paymentsDB package

We introduce a new package paymentsDB and start by moving the
payment specifc errors from the channeldb package to the
paymentsDB package. We also fix linter issues which showed up
due to changing this code part.

routing/mock_test.go

@@ -13,6 +13,7 @@ import (
 	"github.com/lightningnetwork/lnd/htlcswitch"
 	"github.com/lightningnetwork/lnd/lntypes"
 	"github.com/lightningnetwork/lnd/lnwire"
+	paymentsdb "github.com/lightningnetwork/lnd/payments/db"
 	"github.com/lightningnetwork/lnd/record"
 	"github.com/lightningnetwork/lnd/routing/route"
 	"github.com/lightningnetwork/lnd/routing/shards"
@@ -308,7 +309,7 @@ func (m *mockControlTowerOld) InitPayment(phash lntypes.Hash,
 
 	// Don't allow re-init a successful payment.
 	if _, ok := m.successful[phash]; ok {
-		return channeldb.ErrAlreadyPaid
+		return paymentsdb.ErrAlreadyPaid
 	}
 
 	_, failed := m.failed[phash]
@@ -316,7 +317,7 @@ func (m *mockControlTowerOld) InitPayment(phash lntypes.Hash,
 
 	// If the payment is known, only allow re-init if failed.
 	if ok && !failed {
-		return channeldb.ErrPaymentInFlight
+		return paymentsdb.ErrPaymentInFlight
 	}
 
 	delete(m.failed, phash)
@@ -330,7 +331,7 @@ func (m *mockControlTowerOld) InitPayment(phash lntypes.Hash,
 func (m *mockControlTowerOld) DeleteFailedAttempts(phash lntypes.Hash) error {
 	p, ok := m.payments[phash]
 	if !ok {
-		return channeldb.ErrPaymentNotInitiated
+		return paymentsdb.ErrPaymentNotInitiated
 	}
 
 	var inFlight bool
@@ -347,7 +348,7 @@ func (m *mockControlTowerOld) DeleteFailedAttempts(phash lntypes.Hash) error {
 	}
 
 	if inFlight {
-		return channeldb.ErrPaymentInFlight
+		return paymentsdb.ErrPaymentInFlight
 	}
 
 	return nil
@@ -366,7 +367,7 @@ func (m *mockControlTowerOld) RegisterAttempt(phash lntypes.Hash,
 	// Lookup payment.
 	p, ok := m.payments[phash]
 	if !ok {
-		return channeldb.ErrPaymentNotInitiated
+		return paymentsdb.ErrPaymentNotInitiated
 	}
 
 	var inFlight bool
@@ -387,15 +388,15 @@ func (m *mockControlTowerOld) RegisterAttempt(phash lntypes.Hash,
 	_, failed := m.failed[phash]
 
 	if settled || failed {
-		return channeldb.ErrPaymentTerminal
+		return paymentsdb.ErrPaymentTerminal
 	}
 
 	if settled && !inFlight {
-		return channeldb.ErrPaymentAlreadySucceeded
+		return paymentsdb.ErrPaymentAlreadySucceeded
 	}
 
 	if failed && !inFlight {
-		return channeldb.ErrPaymentAlreadyFailed
+		return paymentsdb.ErrPaymentAlreadyFailed
 	}
 
 	// Add attempt to payment.
@@ -421,7 +422,7 @@ func (m *mockControlTowerOld) SettleAttempt(phash lntypes.Hash,
 	// Only allow setting attempts if the payment is known.
 	p, ok := m.payments[phash]
 	if !ok {
-		return nil, channeldb.ErrPaymentNotInitiated
+		return nil, paymentsdb.ErrPaymentNotInitiated
 	}
 
 	// Find the attempt with this pid, and set the settle info.
@@ -431,10 +432,10 @@ func (m *mockControlTowerOld) SettleAttempt(phash lntypes.Hash,
 		}
 
 		if a.Settle != nil {
-			return nil, channeldb.ErrAttemptAlreadySettled
+			return nil, paymentsdb.ErrAttemptAlreadySettled
 		}
 		if a.Failure != nil {
-			return nil, channeldb.ErrAttemptAlreadyFailed
+			return nil, paymentsdb.ErrAttemptAlreadyFailed
 		}
 
 		p.attempts[i].Settle = settleInfo
@@ -462,7 +463,7 @@ func (m *mockControlTowerOld) FailAttempt(phash lntypes.Hash, pid uint64,
 	// Only allow failing attempts if the payment is known.
 	p, ok := m.payments[phash]
 	if !ok {
-		return nil, channeldb.ErrPaymentNotInitiated
+		return nil, paymentsdb.ErrPaymentNotInitiated
 	}
 
 	// Find the attempt with this pid, and set the failure info.
@@ -472,10 +473,10 @@ func (m *mockControlTowerOld) FailAttempt(phash lntypes.Hash, pid uint64,
 		}
 
 		if a.Settle != nil {
-			return nil, channeldb.ErrAttemptAlreadySettled
+			return nil, paymentsdb.ErrAttemptAlreadySettled
 		}
 		if a.Failure != nil {
-			return nil, channeldb.ErrAttemptAlreadyFailed
+			return nil, paymentsdb.ErrAttemptAlreadyFailed
 		}
 
 		p.attempts[i].Failure = failInfo
@@ -499,7 +500,7 @@ func (m *mockControlTowerOld) FailPayment(phash lntypes.Hash,
 
 	// Payment must be known.
 	if _, ok := m.payments[phash]; !ok {
-		return channeldb.ErrPaymentNotInitiated
+		return paymentsdb.ErrPaymentNotInitiated
 	}
 
 	m.failed[phash] = reason
@@ -521,7 +522,7 @@ func (m *mockControlTowerOld) fetchPayment(phash lntypes.Hash) (
 
 	p, ok := m.payments[phash]
 	if !ok {
-		return nil, channeldb.ErrPaymentNotInitiated
+		return nil, paymentsdb.ErrPaymentNotInitiated
 	}
 
 	mp := &channeldb.MPPayment{