mtc_worker: Compute max_landmarks once

crates/mtc_worker/config/src/lib.rs

@@ -39,6 +39,15 @@ pub struct LogParams {
     pub clean_interval_secs: u64,
 }
 
+impl LogParams {
+    /// Return the maximum number of landmarks that cover unexpired certificates at any given time.
+    pub fn max_landmarks(&self) -> usize {
+        self.max_certificate_lifetime_secs
+            .div_ceil(self.landmark_interval_secs)
+            + 1
+    }
+}
+
 fn default_u8<const V: u8>() -> u8 {
     V
 }

crates/mtc_worker/src/frontend_worker.rs

@@ -477,13 +477,9 @@ async fn get_landmark_sequence(
         return Err("failed to get landmark sequence".into());
     };
 
-    let max_landmarks = params
-        .max_certificate_lifetime_secs
-        .div_ceil(params.landmark_interval_secs)
-        + 1;
-
-    let landmark_sequence = LandmarkSequence::from_bytes(&landmark_sequence_bytes, max_landmarks)
-        .map_err(|e| e.to_string())?;
+    let landmark_sequence =
+        LandmarkSequence::from_bytes(&landmark_sequence_bytes, params.max_landmarks())
+            .map_err(|e| e.to_string())?;
 
     Ok(landmark_sequence)
 }

crates/mtc_worker/src/sequencer_do.rs

@@ -81,10 +81,7 @@ fn checkpoint_callback(env: &Env, name: &str) -> CheckpointCallbacker {
                     }
 
                     // Time to add a new landmark.
-                    let max_landmarks = params
-                        .max_certificate_lifetime_secs
-                        .div_ceil(params.landmark_interval_secs)
-                        + 1;
+                    let max_landmarks = params.max_landmarks();
 
                     // Load current landmark sequence.
                     let mut seq =