src/block/manager.rs

@@ -378,11 +378,6 @@ impl BlockManager {
 		Ok(self.rc.rc.len()?)
 	}
 
-	/// Get number of items in the refcount table
-	pub fn rc_fast_len(&self) -> Result<Option<usize>, Error> {
-		Ok(self.rc.rc.fast_len()?)
-	}
-
 	/// Send command to start/stop/manager scrub worker
 	pub async fn send_scrub_command(&self, cmd: ScrubWorkerCommand) -> Result<(), Error> {
 		let tx = self.tx_scrub_command.load();
@@ -398,7 +393,7 @@ impl BlockManager {
 
 	/// List all resync errors
 	pub fn list_resync_errors(&self) -> Result<Vec<BlockResyncErrorInfo>, Error> {
-		let mut blocks = Vec::with_capacity(self.resync.errors.len());
+		let mut blocks = Vec::with_capacity(self.resync.errors.len()?);
 		for ent in self.resync.errors.iter()? {
 			let (hash, cnt) = ent?;
 			let cnt = ErrorCounter::decode(&cnt);

src/block/metrics.rs

@@ -1,7 +1,6 @@
 use opentelemetry::{global, metrics::*};
 
 use garage_db as db;
-use garage_db::counted_tree_hack::CountedTree;
 
 /// TableMetrics reference all counter used for metrics
 pub struct BlockManagerMetrics {
@@ -29,8 +28,8 @@ impl BlockManagerMetrics {
 	pub fn new(
 		compression_level: Option<i32>,
 		rc_tree: db::Tree,
-		resync_queue: CountedTree,
+		resync_queue: db::Tree,
-		resync_errors: CountedTree,
+		resync_errors: db::Tree,
 	) -> Self {
 		let meter = global::meter("garage_model/block");
 		Self {
@@ -45,15 +44,17 @@ impl BlockManagerMetrics {
 				.init(),
 			_rc_size: meter
 				.u64_value_observer("block.rc_size", move |observer| {
-					if let Ok(Some(v)) = rc_tree.fast_len() {
+					if let Ok(value) = rc_tree.len() {
-						observer.observe(v as u64, &[])
+						observer.observe(value as u64, &[])
 					}
 				})
 				.with_description("Number of blocks known to the reference counter")
 				.init(),
 			_resync_queue_len: meter
 				.u64_value_observer("block.resync_queue_length", move |observer| {
-					observer.observe(resync_queue.len() as u64, &[])
+					if let Ok(value) = resync_queue.len() {
+						observer.observe(value as u64, &[]);
+					}
 				})
 				.with_description(
 					"Number of block hashes queued for local check and possible resync",
@@ -61,7 +62,9 @@ impl BlockManagerMetrics {
 				.init(),
 			_resync_errored_blocks: meter
 				.u64_value_observer("block.resync_errored_blocks", move |observer| {
-					observer.observe(resync_errors.len() as u64, &[])
+					if let Ok(value) = resync_errors.len() {
+						observer.observe(value as u64, &[]);
+					}
 				})
 				.with_description("Number of block hashes whose last resync resulted in an error")
 				.init(),

src/block/resync.rs

@@ -15,7 +15,6 @@ use opentelemetry::{
 };
 
 use garage_db as db;
-use garage_db::counted_tree_hack::CountedTree;
 
 use garage_util::background::*;
 use garage_util::data::*;
@@ -47,9 +46,9 @@ pub(crate) const MAX_RESYNC_WORKERS: usize = 8;
 const INITIAL_RESYNC_TRANQUILITY: u32 = 2;
 
 pub struct BlockResyncManager {
-	pub(crate) queue: CountedTree,
+	pub(crate) queue: db::Tree,
 	pub(crate) notify: Arc<Notify>,
-	pub(crate) errors: CountedTree,
+	pub(crate) errors: db::Tree,
 
 	busy_set: BusySet,
 
@@ -90,12 +89,10 @@ impl BlockResyncManager {
 		let queue = db
 			.open_tree("block_local_resync_queue")
 			.expect("Unable to open block_local_resync_queue tree");
-		let queue = CountedTree::new(queue).expect("Could not count block_local_resync_queue");
 
 		let errors = db
 			.open_tree("block_local_resync_errors")
 			.expect("Unable to open block_local_resync_errors tree");
-		let errors = CountedTree::new(errors).expect("Could not count block_local_resync_errors");
 
 		let persister = PersisterShared::new(&system.metadata_dir, "resync_cfg");
 
@@ -110,16 +107,12 @@ impl BlockResyncManager {
 
 	/// Get lenght of resync queue
 	pub fn queue_len(&self) -> Result<usize, Error> {
-		// This currently can't return an error because the CountedTree hack
+		Ok(self.queue.len()?)
-		// doesn't error on .len(), but this will change when we remove the hack
-		// (hopefully someday!)
-		Ok(self.queue.len())
 	}
 
 	/// Get number of blocks that have an error
 	pub fn errors_len(&self) -> Result<usize, Error> {
-		// (see queue_len comment)
+		Ok(self.errors.len()?)
-		Ok(self.errors.len())
 	}
 
 	/// Clear the error counter for a block and put it in queue immediately

src/db/counted_tree_hack.rs

@@ -1,127 +0,0 @@
-//! This hack allows a db tree to keep in RAM a counter of the number of entries
-//! it contains, which is used to call .len() on it.  This is usefull only for
-//! the sled backend where .len() otherwise would have to traverse the whole
-//! tree to count items.  For sqlite and lmdb, this is mostly useless (but
-//! hopefully not harmfull!). Note that a CountedTree cannot be part of a
-//! transaction.
-
-use std::sync::{
-	atomic::{AtomicUsize, Ordering},
-	Arc,
-};
-
-use crate::{Result, Tree, TxError, Value, ValueIter};
-
-#[derive(Clone)]
-pub struct CountedTree(Arc<CountedTreeInternal>);
-
-struct CountedTreeInternal {
-	tree: Tree,
-	len: AtomicUsize,
-}
-
-impl CountedTree {
-	pub fn new(tree: Tree) -> Result<Self> {
-		let len = tree.len()?;
-		Ok(Self(Arc::new(CountedTreeInternal {
-			tree,
-			len: AtomicUsize::new(len),
-		})))
-	}
-
-	pub fn len(&self) -> usize {
-		self.0.len.load(Ordering::SeqCst)
-	}
-
-	pub fn is_empty(&self) -> bool {
-		self.len() == 0
-	}
-
-	pub fn get<K: AsRef<[u8]>>(&self, key: K) -> Result<Option<Value>> {
-		self.0.tree.get(key)
-	}
-
-	pub fn first(&self) -> Result<Option<(Value, Value)>> {
-		self.0.tree.first()
-	}
-
-	pub fn iter(&self) -> Result<ValueIter<'_>> {
-		self.0.tree.iter()
-	}
-
-	// ---- writing functions ----
-
-	pub fn insert<K, V>(&self, key: K, value: V) -> Result<Option<Value>>
-	where
-		K: AsRef<[u8]>,
-		V: AsRef<[u8]>,
-	{
-		let old_val = self.0.tree.insert(key, value)?;
-		if old_val.is_none() {
-			self.0.len.fetch_add(1, Ordering::SeqCst);
-		}
-		Ok(old_val)
-	}
-
-	pub fn remove<K: AsRef<[u8]>>(&self, key: K) -> Result<Option<Value>> {
-		let old_val = self.0.tree.remove(key)?;
-		if old_val.is_some() {
-			self.0.len.fetch_sub(1, Ordering::SeqCst);
-		}
-		Ok(old_val)
-	}
-
-	pub fn compare_and_swap<K, OV, NV>(
-		&self,
-		key: K,
-		expected_old: Option<OV>,
-		new: Option<NV>,
-	) -> Result<bool>
-	where
-		K: AsRef<[u8]>,
-		OV: AsRef<[u8]>,
-		NV: AsRef<[u8]>,
-	{
-		let old_some = expected_old.is_some();
-		let new_some = new.is_some();
-
-		let tx_res = self.0.tree.db().transaction(|tx| {
-			let old_val = tx.get(&self.0.tree, &key)?;
-			let is_same = match (&old_val, &expected_old) {
-				(None, None) => true,
-				(Some(x), Some(y)) if x == y.as_ref() => true,
-				_ => false,
-			};
-			if is_same {
-				match &new {
-					Some(v) => {
-						tx.insert(&self.0.tree, &key, v)?;
-					}
-					None => {
-						tx.remove(&self.0.tree, &key)?;
-					}
-				}
-				Ok(())
-			} else {
-				Err(TxError::Abort(()))
-			}
-		});
-
-		match tx_res {
-			Ok(()) => {
-				match (old_some, new_some) {
-					(false, true) => {
-						self.0.len.fetch_add(1, Ordering::SeqCst);
-					}
-					(true, false) => {
-						self.0.len.fetch_sub(1, Ordering::SeqCst);
-					}
-					_ => (),
-				}
-				Ok(true)
-			}
-			Err(TxError::Abort(())) => Ok(false),
-			Err(TxError::Db(e)) => Err(e),
-		}
-	}
-}

src/db/lib.rs

@@ -6,8 +6,6 @@ pub mod lmdb_adapter;
 #[cfg(feature = "sqlite")]
 pub mod sqlite_adapter;
 
-pub mod counted_tree_hack;
-
 pub mod open;
 
 #[cfg(test)]
@@ -187,10 +185,6 @@ impl Tree {
 	pub fn len(&self) -> Result<usize> {
 		self.0.len(self.1)
 	}
-	#[inline]
-	pub fn fast_len(&self) -> Result<Option<usize>> {
-		self.0.fast_len(self.1)
-	}
 
 	#[inline]
 	pub fn first(&self) -> Result<Option<(Value, Value)>> {
@@ -326,9 +320,6 @@ pub(crate) trait IDb: Send + Sync {
 
 	fn get(&self, tree: usize, key: &[u8]) -> Result<Option<Value>>;
 	fn len(&self, tree: usize) -> Result<usize>;
-	fn fast_len(&self, _tree: usize) -> Result<Option<usize>> {
-		Ok(None)
-	}
 
 	fn insert(&self, tree: usize, key: &[u8], value: &[u8]) -> Result<Option<Value>>;
 	fn remove(&self, tree: usize, key: &[u8]) -> Result<Option<Value>>;

src/db/lmdb_adapter.rs

@@ -121,10 +121,6 @@ impl IDb for LmdbDb {
 		Ok(tree.len(&tx)?.try_into().unwrap())
 	}
 
-	fn fast_len(&self, tree: usize) -> Result<Option<usize>> {
-		Ok(Some(self.len(tree)?))
-	}
-
 	fn insert(&self, tree: usize, key: &[u8], value: &[u8]) -> Result<Option<Value>> {
 		let tree = self.get_tree(tree)?;
 		let mut tx = self.db.write_txn()?;

src/db/sqlite_adapter.rs

@@ -144,10 +144,6 @@ impl IDb for SqliteDb {
 		}
 	}
 
-	fn fast_len(&self, tree: usize) -> Result<Option<usize>> {
-		Ok(Some(self.len(tree)?))
-	}
-
 	fn insert(&self, tree: usize, key: &[u8], value: &[u8]) -> Result<Option<Value>> {
 		trace!("insert {}: lock db", tree);
 		let this = self.0.lock().unwrap();

src/garage/admin/mod.rs

@@ -217,11 +217,11 @@ impl AdminRpcHandler {
 
 		// Gather table statistics
 		let mut table = vec!["  Table\tItems\tMklItems\tMklTodo\tGcTodo".into()];
-		table.push(self.gather_table_stats(&self.garage.bucket_table, opt.detailed)?);
+		table.push(self.gather_table_stats(&self.garage.bucket_table)?);
-		table.push(self.gather_table_stats(&self.garage.key_table, opt.detailed)?);
+		table.push(self.gather_table_stats(&self.garage.key_table)?);
-		table.push(self.gather_table_stats(&self.garage.object_table, opt.detailed)?);
+		table.push(self.gather_table_stats(&self.garage.object_table)?);
-		table.push(self.gather_table_stats(&self.garage.version_table, opt.detailed)?);
+		table.push(self.gather_table_stats(&self.garage.version_table)?);
-		table.push(self.gather_table_stats(&self.garage.block_ref_table, opt.detailed)?);
+		table.push(self.gather_table_stats(&self.garage.block_ref_table)?);
 		write!(
 			&mut ret,
 			"\nTable stats:\n{}",
@@ -231,15 +231,7 @@ impl AdminRpcHandler {
 
 		// Gather block manager statistics
 		writeln!(&mut ret, "\nBlock manager stats:").unwrap();
-		let rc_len = if opt.detailed {
+		let rc_len = self.garage.block_manager.rc_len()?.to_string();
-			self.garage.block_manager.rc_len()?.to_string()
-		} else {
-			self.garage
-				.block_manager
-				.rc_fast_len()?
-				.map(|x| x.to_string())
-				.unwrap_or_else(|| "NC".into())
-		};
 
 		writeln!(
 			&mut ret,
@@ -260,10 +252,6 @@ impl AdminRpcHandler {
 		)
 		.unwrap();
 
-		if !opt.detailed {
-			writeln!(&mut ret, "\nIf values are missing above (marked as NC), consider adding the --detailed flag (this will be slow).").unwrap();
-		}
-
 		if !opt.skip_global {
 			write!(&mut ret, "\n{}", self.gather_cluster_stats()).unwrap();
 		}
@@ -365,34 +353,13 @@ impl AdminRpcHandler {
 		ret
 	}
 
-	fn gather_table_stats<F, R>(
+	fn gather_table_stats<F, R>(&self, t: &Arc<Table<F, R>>) -> Result<String, Error>
-		&self,
-		t: &Arc<Table<F, R>>,
-		detailed: bool,
-	) -> Result<String, Error>
 	where
 		F: TableSchema + 'static,
 		R: TableReplication + 'static,
 	{
-		let (data_len, mkl_len) = if detailed {
+		let data_len = t.data.store.len().map_err(GarageError::from)?.to_string();
-			(
+		let mkl_len = t.merkle_updater.merkle_tree_len()?.to_string();
-				t.data.store.len().map_err(GarageError::from)?.to_string(),
-				t.merkle_updater.merkle_tree_len()?.to_string(),
-			)
-		} else {
-			(
-				t.data
-					.store
-					.fast_len()
-					.map_err(GarageError::from)?
-					.map(|x| x.to_string())
-					.unwrap_or_else(|| "NC".into()),
-				t.merkle_updater
-					.merkle_tree_fast_len()?
-					.map(|x| x.to_string())
-					.unwrap_or_else(|| "NC".into()),
-			)
-		};
 
 		Ok(format!(
 			"  {}\t{}\t{}\t{}\t{}",

src/garage/cli/structs.rs

@@ -553,10 +553,6 @@ pub struct StatsOpt {
 	#[structopt(short = "a", long = "all-nodes")]
 	pub all_nodes: bool,
 
-	/// Gather detailed statistics (this can be long)
-	#[structopt(short = "d", long = "detailed")]
-	pub detailed: bool,
-
 	/// Don't show global cluster stats (internal use in RPC)
 	#[structopt(skip)]
 	#[serde(default)]

src/model/s3/lifecycle_worker.rs

@@ -121,13 +121,7 @@ impl Worker for LifecycleWorker {
 				mpu_aborted,
 				..
 			} => {
-				let n_objects = self
+				let n_objects = self.garage.object_table.data.store.len().ok();
-					.garage
-					.object_table
-					.data
-					.store
-					.fast_len()
-					.unwrap_or(None);
 				let progress = match n_objects {
 					None => "...".to_string(),
 					Some(total) => format!(

src/table/data.rs

@@ -6,7 +6,6 @@ use serde_bytes::ByteBuf;
 use tokio::sync::Notify;
 
 use garage_db as db;
-use garage_db::counted_tree_hack::CountedTree;
 
 use garage_util::data::*;
 use garage_util::error::*;
@@ -36,7 +35,7 @@ pub struct TableData<F: TableSchema, R: TableReplication> {
 	pub(crate) insert_queue: db::Tree,
 	pub(crate) insert_queue_notify: Arc<Notify>,
 
-	pub(crate) gc_todo: CountedTree,
+	pub(crate) gc_todo: db::Tree,
 
 	pub(crate) metrics: TableMetrics,
 }
@@ -61,7 +60,6 @@ impl<F: TableSchema, R: TableReplication> TableData<F, R> {
 		let gc_todo = db
 			.open_tree(format!("{}:gc_todo_v2", F::TABLE_NAME))
 			.expect("Unable to open GC DB tree");
-		let gc_todo = CountedTree::new(gc_todo).expect("Cannot count gc_todo_v2");
 
 		let metrics = TableMetrics::new(
 			F::TABLE_NAME,
@@ -370,6 +368,6 @@ impl<F: TableSchema, R: TableReplication> TableData<F, R> {
 	}
 
 	pub fn gc_todo_len(&self) -> Result<usize, Error> {
-		Ok(self.gc_todo.len())
+		Ok(self.gc_todo.len()?)
 	}
 }

src/table/gc.rs

@@ -10,7 +10,7 @@ use serde_bytes::ByteBuf;
 use futures::future::join_all;
 use tokio::sync::watch;
 
-use garage_db::counted_tree_hack::CountedTree;
+use garage_db as db;
 
 use garage_util::background::*;
 use garage_util::data::*;
@@ -376,7 +376,7 @@ impl GcTodoEntry {
 	}
 
 	/// Saves the GcTodoEntry in the gc_todo tree
-	pub(crate) fn save(&self, gc_todo_tree: &CountedTree) -> Result<(), Error> {
+	pub(crate) fn save(&self, gc_todo_tree: &db::Tree) -> Result<(), Error> {
 		gc_todo_tree.insert(self.todo_table_key(), self.value_hash.as_slice())?;
 		Ok(())
 	}
@@ -386,12 +386,14 @@ impl GcTodoEntry {
 	/// This is usefull to remove a todo entry only under the condition
 	/// that it has not changed since the time it was read, i.e.
 	/// what we have to do is still the same
-	pub(crate) fn remove_if_equal(&self, gc_todo_tree: &CountedTree) -> Result<(), Error> {
+	pub(crate) fn remove_if_equal(&self, gc_todo_tree: &db::Tree) -> Result<(), Error> {
-		gc_todo_tree.compare_and_swap::<_, _, &[u8]>(
+		gc_todo_tree.db().transaction(|txn| {
-			&self.todo_table_key(),
+			let key = self.todo_table_key();
-			Some(self.value_hash),
+			if txn.get(gc_todo_tree, &key)?.as_deref() == Some(self.value_hash.as_slice()) {
-			None,
+				txn.remove(gc_todo_tree, &key)?;
-		)?;
+			}
+			Ok(())
+		})?;
 		Ok(())
 	}
 

src/table/merkle.rs

@@ -291,10 +291,6 @@ impl<F: TableSchema, R: TableReplication> MerkleUpdater<F, R> {
 		Ok(self.data.merkle_tree.len()?)
 	}
 
-	pub fn merkle_tree_fast_len(&self) -> Result<Option<usize>, Error> {
-		Ok(self.data.merkle_tree.fast_len()?)
-	}
-
 	pub fn todo_len(&self) -> Result<usize, Error> {
 		Ok(self.data.merkle_todo.len()?)
 	}

src/table/metrics.rs

@@ -1,7 +1,6 @@
 use opentelemetry::{global, metrics::*, KeyValue};
 
 use garage_db as db;
-use garage_db::counted_tree_hack::CountedTree;
 
 /// TableMetrics reference all counter used for metrics
 pub struct TableMetrics {
@@ -27,7 +26,7 @@ impl TableMetrics {
 		store: db::Tree,
 		merkle_tree: db::Tree,
 		merkle_todo: db::Tree,
-		gc_todo: CountedTree,
+		gc_todo: db::Tree,
 	) -> Self {
 		let meter = global::meter(table_name);
 		TableMetrics {
@@ -35,9 +34,9 @@ impl TableMetrics {
 				.u64_value_observer(
 					"table.size",
 					move |observer| {
-						if let Ok(Some(v)) = store.fast_len() {
+						if let Ok(value) = store.len() {
 							observer.observe(
-								v as u64,
+								value as u64,
 								&[KeyValue::new("table_name", table_name)],
 							);
 						}
@@ -49,9 +48,9 @@ impl TableMetrics {
 				.u64_value_observer(
 					"table.merkle_tree_size",
 					move |observer| {
-						if let Ok(Some(v)) = merkle_tree.fast_len() {
+						if let Ok(value) = merkle_tree.len() {
 							observer.observe(
-								v as u64,
+								value as u64,
 								&[KeyValue::new("table_name", table_name)],
 							);
 						}
@@ -77,10 +76,12 @@ impl TableMetrics {
 				.u64_value_observer(
 					"table.gc_todo_queue_length",
 					move |observer| {
-						observer.observe(
+                        if let Ok(value) = gc_todo.len() {
-							gc_todo.len() as u64,
+                            observer.observe(
-							&[KeyValue::new("table_name", table_name)],
+                                value as u64,
-						);
+                                &[KeyValue::new("table_name", table_name)],
+                            );
+                        }
 					},
 				)
 				.with_description("Table garbage collector TODO queue length")