Address comments

Author: Michael Rosenberg

crates/mtc_worker/src/frontend_worker.rs

@@ -23,7 +23,7 @@ use mtc_api::{
 use serde::{Deserialize, Serialize};
 use serde_with::{base64::Base64, serde_as};
 use signed_note::VerifierList;
-use std::{collections::VecDeque, time::Duration};
+use std::time::Duration;
 use tlog_tiles::{
     open_checkpoint, CheckpointSigner, CheckpointText, LeafIndex, PendingLogEntry,
     PendingLogEntryBlob,
@@ -70,23 +70,6 @@ pub struct GetCertificateResponse {
     pub landmark_id: usize,
 }
 
-/// GET response structure for the `/get-landmark-bundle` endpoint
-#[derive(Serialize, Deserialize)]
-pub struct LandmarkBundle {
-    pub checkpoint: String,
-    pub subtrees: Vec<SubtreeWithConsistencyProof>,
-    pub landmarks: VecDeque<u64>,
-}
-
-#[serde_as]
-#[derive(Serialize, Deserialize)]
-pub struct SubtreeWithConsistencyProof {
-    #[serde_as(as = "Base64")]
-    pub hash: [u8; 32],
-    #[serde_as(as = "Vec<Base64>")]
-    pub consistency_proof: Vec<[u8; 32]>,
-}
-
 /// Start is the first code run when the Wasm module is loaded.
 #[event(start)]
 fn start() {

crates/mtc_worker/src/sequencer_do.rs

@@ -3,19 +3,18 @@
 
 //! Sequencer is the 'brain' of the CT log, responsible for sequencing entries and maintaining log state.
 
-use std::{future::Future, pin::Pin, time::Duration};
+use std::{collections::VecDeque, time::Duration};
 
-use crate::{
-    frontend_worker::{LandmarkBundle, SubtreeWithConsistencyProof},
-    load_checkpoint_cosigner, load_origin, CONFIG,
-};
+use crate::{load_checkpoint_cosigner, load_origin, CONFIG};
 use generic_log_worker::{
     get_durable_object_name, load_public_bucket,
     log_ops::{prove_subtree_consistency, ProofError},
     CachedRoObjectBucket, CheckpointCallbacker, GenericSequencer, ObjectBucket, SequencerConfig,
     SEQUENCER_BINDING,
 };
 use mtc_api::{BootstrapMtcLogEntry, LandmarkSequence, LANDMARK_BUNDLE_KEY, LANDMARK_KEY};
+use serde::{Deserialize, Serialize};
+use serde_with::{base64::Base64, serde_as};
 use signed_note::Note;
 use tlog_tiles::{CheckpointText, Hash, UnixTimestamp};
 #[allow(clippy::wildcard_imports)]
@@ -59,6 +58,23 @@ impl DurableObject for Sequencer {
     }
 }
 
+#[serde_as]
+#[derive(Serialize, Deserialize)]
+pub struct SubtreeWithConsistencyProof {
+    #[serde_as(as = "Base64")]
+    pub hash: [u8; 32],
+    #[serde_as(as = "Vec<Base64>")]
+    pub consistency_proof: Vec<[u8; 32]>,
+}
+
+/// GET response structure for the `/get-landmark-bundle` endpoint
+#[derive(Serialize, Deserialize)]
+pub struct LandmarkBundle {
+    pub checkpoint: String,
+    pub subtrees: Vec<SubtreeWithConsistencyProof>,
+    pub landmarks: VecDeque<u64>,
+}
+
 /// Return a callback function that gets passed into the generic sequencer and
 /// called each time a new checkpoint is created. For MTC, this is used to
 /// periodically update the landmark checkpoint sequence.
@@ -68,14 +84,18 @@ fn checkpoint_callback(env: &Env, name: &str) -> CheckpointCallbacker {
     Box::new(
         move |old_time: UnixTimestamp, new_time: UnixTimestamp, new_checkpoint_bytes: &[u8]| {
             let new_checkpoint = {
-                // TODO: Make more efficient. There are two unnecessary allocations here
+                // TODO: Make more efficient. There are two unnecessary allocations here.
+
+                // We can unwrap because the checkpoint provided is the checkpoint that the
+                // sequencer just created, so it must be well formed.
                 let note = Note::from_bytes(new_checkpoint_bytes)
                     .expect("freshly created checkpoint is not a note");
                 CheckpointText::from_bytes(note.text())
                     .expect("freshly created checkpoint is not a checkpoint")
             };
             let tree_size = new_checkpoint.size();
             let root_hash = *new_checkpoint.hash();
+            // We can unwrap here for the same reason as above
             let new_checkpoint_str = String::from_utf8(new_checkpoint_bytes.to_vec())
                 .expect("freshly created checkpoint is not UTF-8");