introduce intended graph

1 files changed, 35 insertions, 0 deletions

diff --git a/src/swarm/topology.rs b/src/swarm/topology.rs
index 3731036..063fc41 100644
--- a/src/swarm/topology.rs
+++ b/src/swarm/topology.rs
@@ -119,6 +119,41 @@ pub(crate) fn is_neighbour(state: &AppState, peer: &str) -> bool {
     }
 }
 
+/// Every member's neighbours as the member list makes them, as this node sees it (whom
+/// it can reach, who is stable): the graph each node computes its own part of. Ours as
+/// they are (with members that only connect out, or aren't listed yet). For a map of
+/// the swarm (the dashboard); None until the view is known. A link exists if either end
+/// chose it: draw one if either lists the other. About `members²` work: compute it when
+/// the member list may have changed, not on every look.
+#[cfg_attr(not(feature = "dashboard"), allow(dead_code))]
+pub(crate) fn intended_graph(state: &AppState) -> Option<BTreeMap<String, BTreeSet<String>>> {
+    let view = state.neighbours.read_or_recover();
+    let view = view.as_ref()?;
+    let unreachable = |member: &str| view.unreachable.contains(member);
+    let stable = |member: &str| view.stable.contains(member);
+    let graph = view
+        .members
+        .iter()
+        .map(|member| {
+            let neighbours = if member == state.local_id() {
+                view.neighbours.clone()
+            } else {
+                let own = view.transports.get(member).cloned().unwrap_or_default();
+                neighbours_across(
+                    &view.transports,
+                    member,
+                    &own,
+                    view.k,
+                    &unreachable,
+                    &stable,
+                )
+            };
+            (member.clone(), neighbours)
+        })
+        .collect();
+    Some(graph)
+}
+
 /// How the neighbours changed.
 pub(crate) struct NeighbourChange {
     pub(crate) added: Vec<String>,