Throw an error if there are no witnesses when doing fork detection

informalsystems · Jun 11, 2020 · 7e9279c · 7e9279c
1 parent e044ab5
commit 7e9279c
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Showing 3 changed files with 11 additions and 10 deletions.
diff --git a/light-client/src/errors.rs b/light-client/src/errors.rs
@@ -21,6 +21,9 @@ pub enum ErrorKind {
     #[error("store error")]
     Store,
 
+    #[error("no witnesses")]
+    NoWitnesses,
+
     #[error("no valid peer left")]
     NoValidPeerLeft,
 

diff --git a/light-client/src/peer_list.rs b/light-client/src/peer_list.rs
@@ -35,7 +35,7 @@ impl PeerList {
         self.peers.get_mut(&self.primary)
     }
 
-    pub fn secondaries(&self) -> Vec<&Instance> {
+    pub fn witnesses(&self) -> Vec<&Instance> {
         self.peers
             .keys()
             .filter(|peer_id| peer_id != &&self.primary)
@@ -44,7 +44,7 @@ impl PeerList {
     }
 
     #[pre(peer_id != &self.primary)]
-    pub fn remove_secondary(&mut self, peer_id: &PeerId) {
+    pub fn remove_witness(&mut self, peer_id: &PeerId) {
         self.peers.remove(peer_id);
     }
 

diff --git a/light-client/src/supervisor.rs b/light-client/src/supervisor.rs
@@ -115,7 +115,7 @@ impl Supervisor {
                                         forked.push(block.provider);
                                     }
                                     Fork::Faulty(block, _error) => {
-                                        self.peers.remove_secondary(&block.provider);
+                                        self.peers.remove_witness(&block.provider);
                                         // TODO: Log/record the error
                                     }
                                 }
@@ -156,15 +156,13 @@ impl Supervisor {
         light_block: &LightBlock,
         trusted_state: &LightBlock,
     ) -> Result<Option<Vec<Fork>>, Error> {
-        if self.peers.secondaries().is_empty() {
-            return Ok(None);
+        if self.peers.witnesses().is_empty() {
+            bail!(ErrorKind::NoWitnesses);
         }
 
-        let result = self.fork_detector.detect_forks(
-            light_block,
-            &trusted_state,
-            self.peers.secondaries(),
-        )?;
+        let result =
+            self.fork_detector
+                .detect_forks(light_block, &trusted_state, self.peers.witnesses())?;
 
         match result {
             ForkDetection::Detected(forks) => Ok(Some(forks)),