Add wrapper over sled tree to count items (used for big queues)

src/model/block.rs

@@ -22,6 +22,7 @@ use opentelemetry::{
 use garage_util::data::*;
 use garage_util::error::*;
 use garage_util::metrics::RecordDuration;
+use garage_util::sled_counter::SledCountedTree;
 use garage_util::time::*;
 use garage_util::tranquilizer::Tranquilizer;
 
@@ -155,7 +156,7 @@ pub struct BlockManager {
 
 	rc: sled::Tree,
 
-	resync_queue: sled::Tree,
+	resync_queue: SledCountedTree,
 	resync_notify: Notify,
 
 	system: Arc<System>,
@@ -184,6 +185,7 @@ impl BlockManager {
 		let resync_queue = db
 			.open_tree("block_local_resync_queue")
 			.expect("Unable to open block_local_resync_queue tree");
+		let resync_queue = SledCountedTree::new(resync_queue);
 
 		let endpoint = system
 			.netapp

src/model/block_metrics.rs

@@ -1,5 +1,7 @@
 use opentelemetry::{global, metrics::*};
 
+use garage_util::sled_counter::SledCountedTree;
+
 /// TableMetrics reference all counter used for metrics
 pub struct BlockManagerMetrics {
 	pub(crate) _resync_queue_len: ValueObserver<u64>,
@@ -20,7 +22,7 @@ pub struct BlockManagerMetrics {
 }
 
 impl BlockManagerMetrics {
-	pub fn new(resync_queue: sled::Tree) -> Self {
+	pub fn new(resync_queue: SledCountedTree) -> Self {
 		let meter = global::meter("garage_model/block");
 		Self {
 			_resync_queue_len: meter