From 95b4828780d73153f89d7bc1eb73fd09b39a34bd Mon Sep 17 00:00:00 2001
From: "Johan T. Halseth" <johanth@gmail.com>
Date: Thu, 23 May 2019 20:05:31 +0200
Subject: [PATCH] channeldb: derive PaymentStatus implicitly from stored info

---
 channeldb/control_tower.go | 45 +++++++++++++-------------------------
 channeldb/migrations.go    |  7 ------
 channeldb/payments.go      |  4 ----
 3 files changed, 15 insertions(+), 41 deletions(-)

diff --git a/channeldb/control_tower.go b/channeldb/control_tower.go
index 8d94ae0c..7cbce262 100644
--- a/channeldb/control_tower.go
+++ b/channeldb/control_tower.go
@@ -145,12 +145,6 @@ func (p *paymentControl) InitPayment(paymentHash lntypes.Hash,
 			return err
 		}
 
-		// We'll move it into the InFlight state.
-		err = bucket.Put(paymentStatusKey, StatusInFlight.Bytes())
-		if err != nil {
-			return err
-		}
-
 		// Add the payment info to the bucket, which contains the
 		// static information for this payment
 		err = bucket.Put(paymentCreationInfoKey, infoBytes)
@@ -243,12 +237,7 @@ func (p *paymentControl) Success(paymentHash lntypes.Hash,
 
 		// Record the successful payment info atomically to the
 		// payments record.
-		err = bucket.Put(paymentSettleInfoKey, preimage[:])
-		if err != nil {
-			return err
-		}
-
-		return bucket.Put(paymentStatusKey, StatusSucceeded.Bytes())
+		return bucket.Put(paymentSettleInfoKey, preimage[:])
 	})
 	if err != nil {
 		return err
@@ -284,14 +273,7 @@ func (p *paymentControl) Fail(paymentHash lntypes.Hash,
 
 		// Put the failure reason in the bucket for record keeping.
 		v := []byte{byte(reason)}
-		err = bucket.Put(paymentFailInfoKey, v)
-		if err != nil {
-			return err
-		}
-
-		// A failed response was received for an InFlight payment, mark
-		// it as Failed to allow subsequent attempts.
-		return bucket.Put(paymentStatusKey, StatusFailed.Bytes())
+		return bucket.Put(paymentFailInfoKey, v)
 	})
 	if err != nil {
 		return err
@@ -331,19 +313,22 @@ func nextPaymentSequence(tx *bbolt.Tx) ([]byte, error) {
 	return b, nil
 }
 
-// fetchPaymentStatus fetches the payment status from the bucket.  If the
-// status isn't found, it will default to "StatusUnknown".
+// fetchPaymentStatus fetches the payment status of the payment. If the payment
+// isn't found, it will default to "StatusUnknown".
 func fetchPaymentStatus(bucket *bbolt.Bucket) PaymentStatus {
-	// The default status for all payments that aren't recorded in
-	// database.
-	var paymentStatus = StatusUnknown
-
-	paymentStatusBytes := bucket.Get(paymentStatusKey)
-	if paymentStatusBytes != nil {
-		paymentStatus.FromBytes(paymentStatusBytes)
+	if bucket.Get(paymentSettleInfoKey) != nil {
+		return StatusSucceeded
 	}
 
-	return paymentStatus
+	if bucket.Get(paymentFailInfoKey) != nil {
+		return StatusFailed
+	}
+
+	if bucket.Get(paymentCreationInfoKey) != nil {
+		return StatusInFlight
+	}
+
+	return StatusUnknown
 }
 
 // ensureInFlight checks whether the payment found in the given bucket has
diff --git a/channeldb/migrations.go b/channeldb/migrations.go
index c7263958..0a7098c0 100644
--- a/channeldb/migrations.go
+++ b/channeldb/migrations.go
@@ -843,13 +843,6 @@ func migrateOutgoingPayments(tx *bbolt.Tx) error {
 			return err
 		}
 
-		// Since only completed payments were previously stored as
-		// OutgoingPayments, set the status as Completed.
-		err = bucket.Put(paymentStatusKey, StatusSucceeded.Bytes())
-		if err != nil {
-			return err
-		}
-
 		return nil
 	})
 	if err != nil {
diff --git a/channeldb/payments.go b/channeldb/payments.go
index 2e236771..9eabe37d 100644
--- a/channeldb/payments.go
+++ b/channeldb/payments.go
@@ -53,10 +53,6 @@ var (
 	//
 	paymentsRootBucket = []byte("payments-root-bucket")
 
-	// paymentStatusKey is a key used in the payment's sub-bucket to store
-	// the status of the payment.
-	paymentStatusKey = []byte("payment-status-key")
-
 	// paymentDublicateBucket is the name of a optional sub-bucket within
 	// the payment hash bucket, that is used to hold duplicate payments to
 	// a payment hash. This is needed to support information from earlier