replace Option<LayerAccessStatsReset>::None with LayerAccessStatsReset::NoReset

pageserver/src/http/routes.rs

@@ -536,7 +536,8 @@ async fn layer_map_info_handler(request: Request<Body>) -> Result<Response<Body>
     let timeline_id: TimelineId = parse_request_param(&request, "timeline_id")?;
     check_permission(&request, Some(tenant_id))?;
 
-    let reset: Option<LayerAccessStatsReset> = parse_query_param(&request, "reset")?;
+    let reset: LayerAccessStatsReset =
+        parse_query_param(&request, "reset")?.unwrap_or(LayerAccessStatsReset::NoReset);
 
     let tenant = mgr::get_tenant(tenant_id, true)
         .await

pageserver/src/tenant/storage_layer.rs

@@ -121,6 +121,7 @@ pub enum LayerResidenceStatus {
 
 #[derive(Clone, Copy, strum_macros::EnumString)]
 pub enum LayerAccessStatsReset {
+    NoReset,
     JustTaskKindFlags,
     AllStats,
 }
@@ -249,19 +250,11 @@ impl LayerAccessStats {
         inner.task_kind_flag |= task_kind;
         inner.last_accesses.write(this_access);
     }
-    fn reset(&self, what: LayerAccessStatsReset) {
+    fn to_api_model(
+        &self,
+        reset: LayerAccessStatsReset,
+    ) -> pageserver_api::models::LayerAccessStats {
         let mut inner = self.0.lock().unwrap();
-        match what {
-            LayerAccessStatsReset::JustTaskKindFlags => {
-                inner.task_kind_flag.clear();
-            }
-            LayerAccessStatsReset::AllStats => {
-                *inner = LayerAccessStatsInner::default();
-            }
-        }
-    }
-    fn to_api_model(&self) -> pageserver_api::models::LayerAccessStats {
-        let inner = self.0.lock().unwrap();
         let LayerAccessStatsInner {
             first_access,
             count_by_access_kind,
@@ -269,7 +262,7 @@ impl LayerAccessStats {
             last_accesses,
             last_residence_changes,
         } = &*inner;
-        pageserver_api::models::LayerAccessStats {
+        let ret = pageserver_api::models::LayerAccessStats {
             access_count_by_access_kind: count_by_access_kind
                 .iter()
                 .map(|(kind, count)| (kind, *count))
@@ -284,7 +277,17 @@ impl LayerAccessStats {
                 .iter()
                 .map(|s| s.to_api_model())
                 .collect(),
+        };
+        match reset {
+            LayerAccessStatsReset::NoReset => (),
+            LayerAccessStatsReset::JustTaskKindFlags => {
+                inner.task_kind_flag.clear();
+            }
+            LayerAccessStatsReset::AllStats => {
+                *inner = LayerAccessStatsInner::default();
+            }
         }
+        ret
     }
 }
 
@@ -395,7 +398,7 @@ pub trait PersistentLayer: Layer {
     /// current_physical_size is computed as the som of this value.
     fn file_size(&self) -> Option<u64>;
 
-    fn info(&self, reset: Option<LayerAccessStatsReset>) -> HistoricLayerInfo;
+    fn info(&self, reset: LayerAccessStatsReset) -> HistoricLayerInfo;
 
     fn access_stats(&self) -> &LayerAccessStats;
 }

pageserver/src/tenant/storage_layer/delta_layer.rs

@@ -426,26 +426,22 @@ impl PersistentLayer for DeltaLayer {
         Some(self.file_size)
     }
 
-    fn info(&self, reset: Option<LayerAccessStatsReset>) -> HistoricLayerInfo {
+    fn info(&self, reset: LayerAccessStatsReset) -> HistoricLayerInfo {
         let layer_file_name = self.filename().file_name();
         let key_range = self.get_key_range();
         let lsn_range = self.get_lsn_range();
 
-        let ret = HistoricLayerInfo::Delta {
+        let access_stats = self.access_stats.to_api_model(reset);
+
+        HistoricLayerInfo::Delta {
             layer_file_name,
             key_start: key_range.start,
             key_end: key_range.end,
             lsn_start: lsn_range.start,
             lsn_end: lsn_range.end,
             remote: false,
-            access_stats: self.access_stats.to_api_model(),
-        };
-
-        if let Some(reset) = reset {
-            self.access_stats.reset(reset);
+            access_stats,
         }
-
-        ret
     }
 
     fn access_stats(&self) -> &LayerAccessStats {

pageserver/src/tenant/storage_layer/image_layer.rs

@@ -238,25 +238,19 @@ impl PersistentLayer for ImageLayer {
         Some(self.file_size)
     }
 
-    fn info(&self, reset: Option<LayerAccessStatsReset>) -> HistoricLayerInfo {
+    fn info(&self, reset: LayerAccessStatsReset) -> HistoricLayerInfo {
         let layer_file_name = self.filename().file_name();
         let key_range = self.get_key_range();
         let lsn_range = self.get_lsn_range();
 
-        let ret = HistoricLayerInfo::Image {
+        HistoricLayerInfo::Image {
             layer_file_name,
             key_start: key_range.start,
             key_end: key_range.end,
             lsn_start: lsn_range.start,
             remote: false,
-            access_stats: self.access_stats.to_api_model(),
-        };
-
-        if let Some(reset) = reset {
-            self.access_stats.reset(reset);
+            access_stats: self.access_stats.to_api_model(reset),
         }
-
-        ret
     }
 
     fn access_stats(&self) -> &LayerAccessStats {

pageserver/src/tenant/storage_layer/remote_layer.rs

@@ -142,7 +142,7 @@ impl PersistentLayer for RemoteLayer {
         self.layer_metadata.file_size()
     }
 
-    fn info(&self, _reset: Option<LayerAccessStatsReset>) -> HistoricLayerInfo {
+    fn info(&self, reset: LayerAccessStatsReset) -> HistoricLayerInfo {
         let layer_file_name = self.filename().file_name();
         let key_range = self.get_key_range();
         let lsn_range = self.get_lsn_range();
@@ -155,7 +155,7 @@ impl PersistentLayer for RemoteLayer {
                 lsn_start: lsn_range.start,
                 lsn_end: lsn_range.end,
                 remote: true,
-                access_stats: self.access_stats.to_api_model(),
+                access_stats: self.access_stats.to_api_model(reset),
             }
         } else {
             HistoricLayerInfo::Image {
@@ -164,7 +164,7 @@ impl PersistentLayer for RemoteLayer {
                 key_end: key_range.end,
                 lsn_start: lsn_range.start,
                 remote: true,
-                access_stats: self.access_stats.to_api_model(),
+                access_stats: self.access_stats.to_api_model(reset),
             }
         }
     }

pageserver/src/tenant/timeline.rs

@@ -820,7 +820,7 @@ impl Timeline {
         self.state.subscribe()
     }
 
-    pub fn layer_map_info(&self, reset: Option<LayerAccessStatsReset>) -> LayerMapInfo {
+    pub fn layer_map_info(&self, reset: LayerAccessStatsReset) -> LayerMapInfo {
         let mut in_memory_layers = Vec::new();
         let layer_map = self.layers.read().unwrap();
         if let Some(open_layer) = &layer_map.open_layer {