loopdb: extract update deserialization

Preparation to prevent code duplication in future refactoring.

loopdb/store.go

@@ -180,17 +180,38 @@ func (s *boltSwapStore) fetchSwaps(bucketKey []byte,
 				return errors.New("contract not found")
 			}
 
+			updates, err := deserializeUpdates(swapBucket)
+			if err != nil {
+				return err
+			}
+
+			var hash lntypes.Hash
+			copy(hash[:], swapHash)
+
+			loop := Loop{
+				Hash:   hash,
+				Events: updates,
+			}
+
+			return callback(contractBytes, loop)
+		})
+	})
+}
+
+// deserializeUpdates deserializes the list of swap updates that are stored as a
+// key of the given bucket.
+func deserializeUpdates(swapBucket *bbolt.Bucket) ([]*LoopEvent, error) {
 	// Once we have the raw swap, we'll also need to decode
 	// each of the past updates to the swap itself.
 	stateBucket := swapBucket.Bucket(updatesBucketKey)
 	if stateBucket == nil {
-				return errors.New("updates bucket not found")
+		return nil, errors.New("updates bucket not found")
 	}
 
-			// De serialize and collect each swap update into our
+	// Deserialize and collect each swap update into our slice of swap
-			// slice of swap events.
+	// events.
 	var updates []*LoopEvent
-			err := stateBucket.ForEach(func(k, v []byte) error {
+	err := stateBucket.ForEach(func(_, v []byte) error {
 		event, err := deserializeLoopEvent(v)
 		if err != nil {
 			return err
@@ -200,20 +221,10 @@ func (s *boltSwapStore) fetchSwaps(bucketKey []byte,
 		return nil
 	})
 	if err != nil {
-				return err
+		return nil, err
-			}
-
-			var hash lntypes.Hash
-			copy(hash[:], swapHash)
-
-			loop := Loop{
-				Hash:   hash,
-				Events: updates,
 	}
 
-			return callback(contractBytes, loop)
+	return updates, nil
-		})
-	})
 }
 
 // FetchLoopOutSwaps returns all loop out swaps currently in the store.