rpc: Add support for consensus_state endpoint (#719)

* Add RPC support for consensus_state endpoint

Signed-off-by: Thane Thomson <connect@thanethomson.com>

* Add test support for consensus_state endpoint

Signed-off-by: Thane Thomson <connect@thanethomson.com>

* Add consensus state vote summary de/serialization

Signed-off-by: Thane Thomson <connect@thanethomson.com>

* Expose custom RFC3339-compatible timestamp serialization method

Signed-off-by: Thane Thomson <connect@thanethomson.com>

* Use custom RFC3339-compatible timestamp serialization

Signed-off-by: Thane Thomson <connect@thanethomson.com>

* Expand testing for consensus_state endpoint

Signed-off-by: Thane Thomson <connect@thanethomson.com>

* Rather operate on slices of deserialized string

Signed-off-by: Thane Thomson <connect@thanethomson.com>

* Fix timestamp serialization

Signed-off-by: Thane Thomson <connect@thanethomson.com>

* Remove endpoint "unstable" notice

Signed-off-by: Thane Thomson <connect@thanethomson.com>

proto/src/serializers/timestamp.rs

@@ -46,16 +46,18 @@ where
     }
     match Utc.timestamp_opt(value.seconds, value.nanos as u32) {
         LocalResult::None => Err(S::Error::custom("invalid time")),
-        LocalResult::Single(t) => Ok(to_rfc3339_custom(t)),
+        LocalResult::Single(t) => Ok(to_rfc3339_custom(&t)),
         LocalResult::Ambiguous(_, _) => Err(S::Error::custom("ambiguous time")),
     }?
     .serialize(serializer)
 }
 
-// Due to incompatibilities between the way that `chrono` serializes timestamps
-// and the way that Go does for RFC3339, we unfortunately need to define our
-// own timestamp serialization mechanism.
-fn to_rfc3339_custom(t: DateTime<Utc>) -> String {
+/// Serialization helper for converting a `DateTime<Utc>` object to a string.
+///
+/// Due to incompatibilities between the way that `chrono` serializes timestamps
+/// and the way that Go does for RFC3339, we unfortunately need to define our
+/// own timestamp serialization mechanism.
+pub fn to_rfc3339_custom(t: &DateTime<Utc>) -> String {
     let nanos = format!(".{}", t.nanosecond());
     format!(
         "{:04}-{:02}-{:02}T{:02}:{:02}:{:02}{}Z",

rpc-probe/src/kvstore.rs

@@ -71,6 +71,10 @@ pub fn commit(height: u64) -> PlannedInteraction {
     .into()
 }
 
+pub fn consensus_state() -> PlannedInteraction {
+    Request::new("consensus_state", json!({})).into()
+}
+
 pub fn genesis() -> PlannedInteraction {
     Request::new("genesis", json!({})).into()
 }

rpc-probe/src/quick.rs

@@ -23,6 +23,7 @@ pub fn quick_probe_plan(output_path: &Path, request_wait: Duration) -> Result<Pl
                 block_results(10).with_name("block_results_at_height_10"),
                 blockchain(1, 10).with_name("blockchain_from_1_to_10"),
                 commit(10).with_name("commit_at_height_10"),
+                consensus_state(),
                 broadcast_tx("async", "async-key", "value"),
                 broadcast_tx("sync", "sync-key", "value"),
                 broadcast_tx("commit", "commit-key", "value"),

rpc/src/client.rs

@@ -118,6 +118,11 @@ pub trait Client {
         self.perform(commit::Request::new(height.into())).await
     }
 
+    /// `/consensus_state`: get current consensus state
+    async fn consensus_state(&self) -> Result<consensus_state::Response> {
+        self.perform(consensus_state::Request::new()).await
+    }
+
     /// `/validators`: get validators a given height.
     async fn validators<H>(&self, height: H) -> Result<validators::Response>
     where

rpc/src/endpoint.rs

@@ -7,6 +7,7 @@ pub mod block_results;
 pub mod blockchain;
 pub mod broadcast;
 pub mod commit;
+pub mod consensus_state;
 pub mod evidence;
 pub mod genesis;
 pub mod health;