channeldb+funding: move policy encoding into channel DB

channeldb/forwarding_policy.go

@@ -1,6 +1,10 @@
 package channeldb
 
-import "github.com/lightningnetwork/lnd/kvdb"
+import (
+	"github.com/lightningnetwork/lnd/channeldb/models"
+	"github.com/lightningnetwork/lnd/kvdb"
+	"github.com/lightningnetwork/lnd/lnwire"
+)
 
 var (
 	// initialChannelForwardingPolicyBucket is the database bucket used to
@@ -13,8 +17,18 @@ var (
 
 // SaveInitialForwardingPolicy saves the serialized forwarding policy for the
 // provided permanent channel id to the initialChannelForwardingPolicyBucket.
-func (c *ChannelStateDB) SaveInitialForwardingPolicy(chanID,
-	forwardingPolicy []byte) error {
+func (c *ChannelStateDB) SaveInitialForwardingPolicy(chanID lnwire.ChannelID,
+	forwardingPolicy *models.ForwardingPolicy) error {
+
+	chanIDCopy := make([]byte, 32)
+	copy(chanIDCopy, chanID[:])
+
+	scratch := make([]byte, 36)
+	byteOrder.PutUint64(scratch[:8], uint64(forwardingPolicy.MinHTLCOut))
+	byteOrder.PutUint64(scratch[8:16], uint64(forwardingPolicy.MaxHTLC))
+	byteOrder.PutUint64(scratch[16:24], uint64(forwardingPolicy.BaseFee))
+	byteOrder.PutUint64(scratch[24:32], uint64(forwardingPolicy.FeeRate))
+	byteOrder.PutUint32(scratch[32:], forwardingPolicy.TimeLockDelta)
 
 	return kvdb.Update(c.backend, func(tx kvdb.RwTx) error {
 		bucket, err := tx.CreateTopLevelBucket(
@@ -24,17 +38,20 @@ func (c *ChannelStateDB) SaveInitialForwardingPolicy(chanID,
 			return err
 		}
 
-		return bucket.Put(chanID, forwardingPolicy)
+		return bucket.Put(chanIDCopy, scratch)
 	}, func() {})
 }
 
 // GetInitialForwardingPolicy fetches the serialized forwarding policy for the
 // provided channel id from the database, or returns ErrChannelNotFound if
 // a forwarding policy for this channel id is not found.
-func (c *ChannelStateDB) GetInitialForwardingPolicy(chanID []byte) ([]byte,
-	error) {
+func (c *ChannelStateDB) GetInitialForwardingPolicy(
+	chanID lnwire.ChannelID) (*models.ForwardingPolicy, error) {
 
-	var serializedState []byte
+	chanIDCopy := make([]byte, 32)
+	copy(chanIDCopy, chanID[:])
+
+	var forwardingPolicy *models.ForwardingPolicy
 	err := kvdb.View(c.backend, func(tx kvdb.RTx) error {
 		bucket := tx.ReadBucket(initialChannelForwardingPolicyBucket)
 		if bucket == nil {
@@ -44,23 +61,43 @@ func (c *ChannelStateDB) GetInitialForwardingPolicy(chanID []byte) ([]byte,
 			return ErrChannelNotFound
 		}
 
-		stateBytes := bucket.Get(chanID)
+		stateBytes := bucket.Get(chanIDCopy)
 		if stateBytes == nil {
 			return ErrChannelNotFound
 		}
 
-		serializedState = append(serializedState, stateBytes...)
+		forwardingPolicy = &models.ForwardingPolicy{
+			MinHTLCOut: lnwire.MilliSatoshi(
+				byteOrder.Uint64(stateBytes[:8]),
+			),
+			MaxHTLC: lnwire.MilliSatoshi(
+				byteOrder.Uint64(stateBytes[8:16]),
+			),
+			BaseFee: lnwire.MilliSatoshi(
+				byteOrder.Uint64(stateBytes[16:24]),
+			),
+			FeeRate: lnwire.MilliSatoshi(
+				byteOrder.Uint64(stateBytes[24:32]),
+			),
+			TimeLockDelta: byteOrder.Uint32(stateBytes[32:36]),
+		}
 
 		return nil
 	}, func() {
-		serializedState = nil
+		forwardingPolicy = nil
 	})
-	return serializedState, err
+
+	return forwardingPolicy, err
 }
 
 // DeleteInitialForwardingPolicy removes the forwarding policy for a given
 // channel from the database.
-func (c *ChannelStateDB) DeleteInitialForwardingPolicy(chanID []byte) error {
+func (c *ChannelStateDB) DeleteInitialForwardingPolicy(
+	chanID lnwire.ChannelID) error {
+
+	chanIDCopy := make([]byte, 32)
+	copy(chanIDCopy, chanID[:])
+
 	return kvdb.Update(c.backend, func(tx kvdb.RwTx) error {
 		bucket := tx.ReadWriteBucket(
 			initialChannelForwardingPolicyBucket,
@@ -69,6 +106,6 @@ func (c *ChannelStateDB) DeleteInitialForwardingPolicy(chanID []byte) error {
 			return ErrChannelNotFound
 		}
 
-		return bucket.Delete(chanID)
+		return bucket.Delete(chanIDCopy)
 	}, func() {})
 }