Add metrics output to SizePartitioningStore

SizePartitioningStore now properly publishes metrics about the
underlying store and config.

towards: #650

nativelink-store/src/size_partitioning_store.rs

@@ -20,11 +20,12 @@ use nativelink_error::{Error, ResultExt};
 use nativelink_util::buf_channel::{DropCloserReadHalf, DropCloserWriteHalf};
 use nativelink_util::common::DigestInfo;
 use nativelink_util::health_utils::{default_health_status_indicator, HealthStatusIndicator};
+use nativelink_util::metrics_utils::{Collector, CollectorState, MetricsComponent, Registry};
 use nativelink_util::store_trait::{Store, UploadSizeInfo};
 use tokio::join;
 
 pub struct SizePartitioningStore {
-    size: i64,
+    partition_size: i64,
     lower_store: Arc<dyn Store>,
     upper_store: Arc<dyn Store>,
 }
@@ -36,7 +37,7 @@ impl SizePartitioningStore {
         upper_store: Arc<dyn Store>,
     ) -> Self {
         SizePartitioningStore {
-            size: config.size as i64,
+            partition_size: config.size as i64,
             lower_store,
             upper_store,
         }
@@ -53,7 +54,7 @@ impl Store for SizePartitioningStore {
         let (lower_digests, upper_digests): (Vec<_>, Vec<_>) = digests
             .iter()
             .cloned()
-            .partition(|digest| digest.size_bytes < self.size);
+            .partition(|digest| digest.size_bytes < self.partition_size);
         let (lower_results, upper_results) = join!(
             Pin::new(self.lower_store.as_ref()).has_many(&lower_digests),
             Pin::new(self.upper_store.as_ref()).has_many(&upper_digests),
@@ -88,11 +89,12 @@ impl Store for SizePartitioningStore {
         reader: DropCloserReadHalf,
         size_info: UploadSizeInfo,
     ) -> Result<(), Error> {
-        if digest.size_bytes < self.size {
+        if digest.size_bytes < self.partition_size {
             return Pin::new(self.lower_store.as_ref())
                 .update(digest, reader, size_info)
                 .await;
         }
+
         Pin::new(self.upper_store.as_ref())
             .update(digest, reader, size_info)
             .await
@@ -105,7 +107,7 @@ impl Store for SizePartitioningStore {
         offset: usize,
         length: Option<usize>,
     ) -> Result<(), Error> {
-        if digest.size_bytes < self.size {
+        if digest.size_bytes < self.partition_size {
             return Pin::new(self.lower_store.as_ref())
                 .get_part_ref(digest, writer, offset, length)
                 .await;
@@ -119,7 +121,7 @@ impl Store for SizePartitioningStore {
         let Some(digest) = digest else {
             return self;
         };
-        if digest.size_bytes < self.size {
+        if digest.size_bytes < self.partition_size {
             return self.lower_store.inner_store(Some(digest));
         }
         self.upper_store.inner_store(Some(digest))
@@ -129,7 +131,7 @@ impl Store for SizePartitioningStore {
         let Some(digest) = digest else {
             return self;
         };
-        if digest.size_bytes < self.size {
+        if digest.size_bytes < self.partition_size {
             return self.lower_store.clone().inner_store_arc(Some(digest));
         }
         self.upper_store.clone().inner_store_arc(Some(digest))
@@ -142,6 +144,28 @@ impl Store for SizePartitioningStore {
     fn as_any_arc(self: Arc<Self>) -> Arc<dyn std::any::Any + Sync + Send + 'static> {
         self
     }
+
+    fn register_metrics(self: Arc<Self>, registry: &mut Registry) {
+        let lower_store_registry = registry.sub_registry_with_prefix("lower_store");
+        self.lower_store
+            .clone()
+            .register_metrics(lower_store_registry);
+        let upper_store_registry = registry.sub_registry_with_prefix("upper_store");
+        self.upper_store
+            .clone()
+            .register_metrics(upper_store_registry);
+        registry.register_collector(Box::new(Collector::new(&self)));
+    }
+}
+
+impl MetricsComponent for SizePartitioningStore {
+    fn gather_metrics(&self, c: &mut CollectorState) {
+        c.publish(
+            "partition_size",
+            &self.partition_size,
+            "Size to partition our data",
+        );
+    }
 }
 
 default_health_status_indicator!(SizePartitioningStore);