dashboard: add epoch switch indicator

2 files changed, 33 insertions, 7 deletions

diff --git a/src/remake/local.rs b/src/remake/local.rs
index c80a5a5..e13c6fd 100644
--- a/src/remake/local.rs
+++ b/src/remake/local.rs
@@ -253,6 +253,12 @@ impl RemakeState {
             .or_insert_with(Instant::now)
     }
 
+    /// How long ago this node first saw remake `id` committed (`first_seen`), if it did.
+    #[cfg_attr(not(feature = "dashboard"), allow(dead_code))]
+    pub(crate) fn seen_for(&self, id: &str) -> Option<std::time::Duration> {
+        self.lock().first_seen.get(id).map(|at| at.elapsed())
+    }
+
     pub(crate) fn status(&self, id: &str) -> Option<LocalStatus> {
         self.lock().status.get(id).cloned()
     }
diff --git a/src/remake/mod.rs b/src/remake/mod.rs
index 2273456..b16b8a3 100644
--- a/src/remake/mod.rs
+++ b/src/remake/mod.rs
@@ -88,12 +88,21 @@ pub(crate) struct Current {
     pub(crate) voters: Vec<String>,
     /// The epoch's generation it remakes: a member past it switched.
     pub(crate) from_generation: u64,
+    /// Committed: the wait between seeing the commit and switching
+    /// (`Proposal::switch_delay_ms`), and how much of it is left on this node (ms).
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(crate) switch_delay_ms: Option<u64>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub(crate) switch_in_ms: Option<u64>,
 }
 
 /// The remakes of `epoch` in `doc`, with their phase at `now` (expiry by `grace`, this
-/// node's for records without their own: `Record::phase`).
+/// node's `dormant_after`, for records without their own: `Record::phase`), and for one
+/// committed, this node's wait to switch (`remake`: when it saw the commit; as
+/// `switch::check` waits: the proposal's delay, or a quarter of `grace`).
 #[cfg_attr(not(feature = "dashboard"), allow(dead_code))]
 pub(crate) fn current(
+    remake: &RemakeState,
     doc: &Document,
     epoch: Epoch,
     now: crate::clock::UnixMillis,
@@ -103,12 +112,23 @@ pub(crate) fn current(
     records::load_all(doc)
         .into_iter()
         .filter(|(_, record)| record.proposal.from_epoch == local)
-        .map(|(id, record)| Current {
-            phase: record.phase(now, grace),
-            coordinator: record.proposal.coordinator.clone(),
-            voters: record.votes.keys().cloned().collect(),
-            from_generation: local.generation,
-            id,
+        .map(|(id, record)| {
+            let phase = record.phase(now, grace);
+            let delay = (phase == records::Phase::Committed)
+                .then(|| record.proposal.switch_delay_ms.unwrap_or(grace / 4));
+            let left = delay.and_then(|delay| {
+                let seen = remake.seen_for(&id)?;
+                Some(delay.saturating_sub(seen.as_millis() as u64))
+            });
+            Current {
+                phase,
+                coordinator: record.proposal.coordinator.clone(),
+                voters: record.votes.keys().cloned().collect(),
+                from_generation: local.generation,
+                switch_delay_ms: delay,
+                switch_in_ms: left,
+                id,
+            }
         })
         .collect()
 }