chore: fix some typos in comments (#586)

Signed-off-by: tgolang <seekseat@aliyun.com>

backend/common/src/rolling_total.rs

@@ -50,14 +50,14 @@ impl RollingTotalBuilder {
 
     /// Set the size of the window of time that we'll look back on
     /// to sum up values over to give us the current total. The size
-    /// is set as a multiple of the granularity; a granulatiry of 1s
+    /// is set as a multiple of the granularity; a granularity of 1s
     /// and a size of 10 means the window size will be 10 seconds.
     pub fn window_size_multiple(mut self, val: usize) -> Self {
         self.window_size_multiple = val;
         self
     }
 
-    /// What is the granulatiry of our windows of time. For example, a
+    /// What is the granularity of our windows of time. For example, a
     /// granularity of 5 seconds means that every 5 seconds the window
     /// that we look at shifts forward to the next 5 seconds worth of data.
     /// A larger granularity is more efficient but less accurate than a
@@ -69,7 +69,7 @@ impl RollingTotalBuilder {
 }
 
 impl<Time: TimeSource> RollingTotalBuilder<Time> {
-    /// Create a [`RollingTotal`] with these setings, starting from the
+    /// Create a [`RollingTotal`] with these settings, starting from the
     /// instant provided.
     pub fn start<T>(self) -> RollingTotal<T, Time>
     where

backend/telemetry_core/src/state/counter.rs

@@ -39,7 +39,7 @@ impl<K> Counter<K>
 where
     K: Sized + std::hash::Hash + Eq,
 {
-    /// Either adds or removes a single occurence of a given `key`.
+    /// Either adds or removes a single occurrence of a given `key`.
     pub fn modify<'a, Q>(&mut self, key: Option<&'a Q>, op: CounterValue)
     where
         Q: ?Sized + std::hash::Hash + Eq,

backend/telemetry_core/tests/e2e_tests.rs

@@ -767,7 +767,7 @@ async fn e2e_slow_feeds_are_disconnected() {
 }
 
 /// If something connects to the `/submit` endpoint, there is a limit to the number
-/// of different messags IDs it can send telemetry about, to prevent a malicious actor from
+/// of different messages IDs it can send telemetry about, to prevent a malicious actor from
 /// spamming a load of message IDs and exhausting our memory.
 #[tokio::test]
 async fn e2e_max_nodes_per_connection_is_enforced() {