merkledb comment accuracy fixes (#2780)

Signed-off-by: Dan Laine <daniel.laine@avalabs.org>
Co-authored-by: Darioush Jalali <darioush.jalali@avalabs.org>

x/merkledb/proof.go

@@ -734,8 +734,8 @@ func verifyProofPath(proof []ProofNode, key maybe.Maybe[Key]) error {
 		currentProofNode := proof[i]
 		nodeKey := currentProofNode.Key
 
-		// Because the interface only support []byte keys,
-		// a key with a partial byte should store a value
+		// Because the interface only supports []byte keys,
+		// a key with a partial byte may not store a value
 		if nodeKey.hasPartialByte() && proof[i].ValueOrHash.HasValue() {
 			return ErrPartialByteLengthWithValue
 		}

x/merkledb/trie.go

@@ -92,11 +92,10 @@ type View interface {
 	CommitToDB(ctx context.Context) error
 }
 
-// Returns the nodes along the path to [key].
+// Calls [visitNode] on the nodes along the path to [key].
 // The first node is the root, and the last node is either the node with the
 // given [key], if it's in the trie, or the node with the largest prefix of
 // the [key] if it isn't in the trie.
-// Always returns at least the root node.
 // Assumes [t] doesn't change while this function is running.
 func visitPathToKey(t Trie, key Key, visitNode func(*node) error) error {
 	maybeRoot := t.getRoot()
@@ -137,7 +136,7 @@ func visitPathToKey(t Trie, key Key, visitNode func(*node) error) error {
 	return nil
 }
 
-// Returns a proof that [bytesPath] is in or not in trie [t].
+// Returns a proof that [key] is in or not in trie [t].
 // Assumes [t] doesn't change while this function is running.
 func getProof(t Trie, key []byte) (*Proof, error) {
 	root := t.getRoot()

x/merkledb/view.go

@@ -471,7 +471,7 @@ func (v *view) getValue(key Key) ([]byte, error) {
 	}
 	v.db.metrics.ViewChangesValueMiss()
 
-	// if we don't have local copy of the key, then grab a copy from the parent trie
+	// if we don't have local copy of the value, then grab a copy from the parent trie
 	value, err := v.getParentTrie().getValue(key)
 	if err != nil {
 		return nil, err
@@ -542,15 +542,12 @@ func (v *view) remove(key Key) error {
 		return v.compressNodePath(grandParent, parent)
 	}
 
-	// merge this node and its descendants into a single node if possible
+	// merge this node and its parent into a single node if possible
 	return v.compressNodePath(parent, nodeToDelete)
 }
 
-// Merges together nodes in the inclusive descendants of [n] that
-// have no value and a single child into one node with a compressed
-// path until a node that doesn't meet those criteria is reached.
-// [parent] is [n]'s parent. If [parent] is nil, [n] is the root
-// node and [v.root] is updated to [n].
+// Merges [n] with its [parent] if [n] has only one child and no value.
+// If [parent] is nil, [n] is the root node and [v.root] is updated to [n].
 // Assumes at least one of the following is true:
 // * [n] has a value.
 // * [n] has children.