Add a gossip version parameter to ForEachNodeDirectedChannel on the Store interface and both DB implementations (KVStore, SQLStore). The NodeTraverser and routing.Graph interfaces remain unversioned since pathfinding operates on the merged cross-version cache view. The cache population in populateCache is updated in the same commit because it is logically atomic with the versioning changes: the graph cache is the unversioned, merged view used by pathfinding, so it must be populated with data from all gossip versions. Without this change, only v1 data would be loaded into the cache, making v2 nodes and channels invisible to pathfinding.
routing
The routing package implements authentication+validation of channel announcements, pruning of the channel graph, path finding within the network, sending outgoing payments into the network and synchronizing new peers to our channel graph state.
Installation and Updating
$ go get -u github.com/lightningnetwork/lnd/routing