Some refactoring of the index counter API

src/api/k2v/index.rs

@@ -10,7 +10,7 @@ use garage_rpc::ring::Ring;
 use garage_table::util::*;
 
 use garage_model::garage::Garage;
-use garage_model::k2v::counter_table::{BYTES, CONFLICTS, ENTRIES, VALUES};
+use garage_model::k2v::item_table::{BYTES, CONFLICTS, ENTRIES, VALUES};
 
 use crate::k2v::error::*;
 use crate::k2v::range::read_range;

src/model/garage.rs

@@ -27,7 +27,7 @@ use crate::key_table::*;
 #[cfg(feature = "k2v")]
 use crate::index_counter::*;
 #[cfg(feature = "k2v")]
-use crate::k2v::{counter_table::*, item_table::*, poll::*, rpc::*};
+use crate::k2v::{item_table::*, poll::*, rpc::*};
 
 /// An entire Garage full of data
 pub struct Garage {
@@ -66,7 +66,7 @@ pub struct GarageK2V {
 	/// Table containing K2V items
 	pub item_table: Arc<Table<K2VItemTable, TableShardedReplication>>,
 	/// Indexing table containing K2V item counters
-	pub counter_table: Arc<IndexCounter<K2VCounterTable>>,
+	pub counter_table: Arc<IndexCounter<K2VItem>>,
 	/// K2V RPC handler
 	pub rpc: Arc<K2VRpcHandler>,
 }

src/model/index_counter.rs

@@ -17,25 +17,30 @@ use garage_table::crdt::*;
 use garage_table::replication::TableShardedReplication;
 use garage_table::*;
 
-pub trait CounterSchema: Clone + PartialEq + Send + Sync + 'static {
-	const NAME: &'static str;
-	type P: PartitionKey + Clone + PartialEq + Serialize + for<'de> Deserialize<'de> + Send + Sync;
-	type S: SortKey + Clone + PartialEq + Serialize + for<'de> Deserialize<'de> + Send + Sync;
+pub trait CountedItem: Clone + PartialEq + Send + Sync + 'static {
+	const COUNTER_TABLE_NAME: &'static str;
+
+	type CP: PartitionKey + Clone + PartialEq + Serialize + for<'de> Deserialize<'de> + Send + Sync;
+	type CS: SortKey + Clone + PartialEq + Serialize + for<'de> Deserialize<'de> + Send + Sync;
+
+	fn counter_partition_key(&self) -> &Self::CP;
+	fn counter_sort_key(&self) -> &Self::CS;
+	fn counts(&self) -> Vec<(&'static str, i64)>;
 }
 
 /// A counter entry in the global table
-#[derive(PartialEq, Clone, Debug, Serialize, Deserialize)]
-pub struct CounterEntry<T: CounterSchema> {
-	pub pk: T::P,
-	pub sk: T::S,
+#[derive(Clone, PartialEq, Debug, Serialize, Deserialize)]
+pub struct CounterEntry<T: CountedItem> {
+	pub pk: T::CP,
+	pub sk: T::CS,
 	pub values: BTreeMap<String, CounterValue>,
 }
 
-impl<T: CounterSchema> Entry<T::P, T::S> for CounterEntry<T> {
-	fn partition_key(&self) -> &T::P {
+impl<T: CountedItem> Entry<T::CP, T::CS> for CounterEntry<T> {
+	fn partition_key(&self) -> &T::CP {
 		&self.pk
 	}
-	fn sort_key(&self) -> &T::S {
+	fn sort_key(&self) -> &T::CS {
 		&self.sk
 	}
 	fn is_tombstone(&self) -> bool {
@@ -45,7 +50,7 @@ impl<T: CounterSchema> Entry<T::P, T::S> for CounterEntry<T> {
 	}
 }
 
-impl<T: CounterSchema> CounterEntry<T> {
+impl<T: CountedItem> CounterEntry<T> {
 	pub fn filtered_values(&self, ring: &Ring) -> HashMap<String, i64> {
 		let nodes = &ring.layout.node_id_vec[..];
 		self.filtered_values_with_nodes(nodes)
@@ -78,7 +83,7 @@ pub struct CounterValue {
 	pub node_values: BTreeMap<Uuid, (u64, i64)>,
 }
 
-impl<T: CounterSchema> Crdt for CounterEntry<T> {
+impl<T: CountedItem> Crdt for CounterEntry<T> {
 	fn merge(&mut self, other: &Self) {
 		for (name, e2) in other.values.iter() {
 			if let Some(e) = self.values.get_mut(name) {
@@ -104,15 +109,15 @@ impl Crdt for CounterValue {
 	}
 }
 
-pub struct CounterTable<T: CounterSchema> {
+pub struct CounterTable<T: CountedItem> {
 	_phantom_t: PhantomData<T>,
 }
 
-impl<T: CounterSchema> TableSchema for CounterTable<T> {
-	const TABLE_NAME: &'static str = T::NAME;
+impl<T: CountedItem> TableSchema for CounterTable<T> {
+	const TABLE_NAME: &'static str = T::COUNTER_TABLE_NAME;
 
-	type P = T::P;
-	type S = T::S;
+	type P = T::CP;
+	type S = T::CS;
 	type E = CounterEntry<T>;
 	type Filter = (DeletedFilter, Vec<Uuid>);
 
@@ -131,14 +136,14 @@ impl<T: CounterSchema> TableSchema for CounterTable<T> {
 
 // ----
 
-pub struct IndexCounter<T: CounterSchema> {
+pub struct IndexCounter<T: CountedItem> {
 	this_node: Uuid,
 	local_counter: db::Tree,
-	propagate_tx: mpsc::UnboundedSender<(T::P, T::S, LocalCounterEntry)>,
+	propagate_tx: mpsc::UnboundedSender<(T::CP, T::CS, LocalCounterEntry)>,
 	pub table: Arc<Table<CounterTable<T>, TableShardedReplication>>,
 }
 
-impl<T: CounterSchema> IndexCounter<T> {
+impl<T: CountedItem> IndexCounter<T> {
 	pub fn new(
 		system: Arc<System>,
 		replication: TableShardedReplication,
@@ -151,7 +156,7 @@ impl<T: CounterSchema> IndexCounter<T> {
 		let this = Arc::new(Self {
 			this_node: system.id,
 			local_counter: db
-				.open_tree(format!("local_counter:{}", T::NAME))
+				.open_tree(format!("local_counter:{}", T::COUNTER_TABLE_NAME))
 				.expect("Unable to open local counter tree"),
 			propagate_tx,
 			table: Table::new(
@@ -166,7 +171,7 @@ impl<T: CounterSchema> IndexCounter<T> {
 
 		let this2 = this.clone();
 		background.spawn_worker(
-			format!("{} index counter propagator", T::NAME),
+			format!("{} index counter propagator", T::COUNTER_TABLE_NAME),
 			move |must_exit| this2.clone().propagate_loop(propagate_rx, must_exit),
 		);
 		this
@@ -175,10 +180,26 @@ impl<T: CounterSchema> IndexCounter<T> {
 	pub fn count(
 		&self,
 		tx: &mut db::Transaction,
-		pk: &T::P,
-		sk: &T::S,
-		counts: &[(&str, i64)],
+		old: Option<&T>,
+		new: Option<&T>,
 	) -> db::TxResult<(), Error> {
+		let pk = old
+			.map(|e| e.counter_partition_key())
+			.unwrap_or_else(|| new.unwrap().counter_partition_key());
+		let sk = old
+			.map(|e| e.counter_sort_key())
+			.unwrap_or_else(|| new.unwrap().counter_sort_key());
+
+		// calculate counter differences
+		let mut counts = HashMap::new();
+		for (k, v) in old.map(|x| x.counts()).unwrap_or_default() {
+			*counts.entry(k).or_insert(0) -= v;
+		}
+		for (k, v) in new.map(|x| x.counts()).unwrap_or_default() {
+			*counts.entry(k).or_insert(0) += v;
+		}
+
+		// update local counter table
 		let tree_key = self.table.data.tree_key(pk, sk);
 
 		let mut entry = match tx.get(&self.local_counter, &tree_key[..])? {
@@ -213,7 +234,7 @@ impl<T: CounterSchema> IndexCounter<T> {
 
 	async fn propagate_loop(
 		self: Arc<Self>,
-		mut propagate_rx: mpsc::UnboundedReceiver<(T::P, T::S, LocalCounterEntry)>,
+		mut propagate_rx: mpsc::UnboundedReceiver<(T::CP, T::CS, LocalCounterEntry)>,
 		must_exit: watch::Receiver<bool>,
 	) {
 		// This loop batches updates to counters to be sent all at once.
@@ -255,10 +276,10 @@ impl<T: CounterSchema> IndexCounter<T> {
 				if let Err(e) = self.table.insert_many(entries).await {
 					errors += 1;
 					if errors >= 2 && *must_exit.borrow() {
-						error!("({}) Could not propagate {} counter values: {}, these counters will not be updated correctly.", T::NAME, buf.len(), e);
+						error!("({}) Could not propagate {} counter values: {}, these counters will not be updated correctly.", T::COUNTER_TABLE_NAME, buf.len(), e);
 						break;
 					}
-					warn!("({}) Could not propagate {} counter values: {}, retrying in 5 seconds (retry #{})", T::NAME, buf.len(), e, errors);
+					warn!("({}) Could not propagate {} counter values: {}, retrying in 5 seconds (retry #{})", T::COUNTER_TABLE_NAME, buf.len(), e, errors);
 					tokio::time::sleep(Duration::from_secs(5)).await;
 					continue;
 				}
@@ -280,11 +301,11 @@ struct LocalCounterEntry {
 }
 
 impl LocalCounterEntry {
-	fn into_counter_entry<T: CounterSchema>(
+	fn into_counter_entry<T: CountedItem>(
 		self,
 		this_node: Uuid,
-		pk: T::P,
-		sk: T::S,
+		pk: T::CP,
+		sk: T::CS,
 	) -> CounterEntry<T> {
 		CounterEntry {
 			pk,

src/model/k2v/counter_table.rs

@@ -1,20 +0,0 @@
-use garage_util::data::*;
-
-use crate::index_counter::*;
-
-pub const ENTRIES: &str = "entries";
-pub const CONFLICTS: &str = "conflicts";
-pub const VALUES: &str = "values";
-pub const BYTES: &str = "bytes";
-
-#[derive(PartialEq, Clone)]
-pub struct K2VCounterTable;
-
-impl CounterSchema for K2VCounterTable {
-	const NAME: &'static str = "k2v_index_counter";
-
-	// Partition key = bucket id
-	type P = Uuid;
-	// Sort key = K2V item's partition key
-	type S = String;
-}

src/model/k2v/item_table.rs

@@ -10,9 +10,13 @@ use garage_table::*;
 
 use crate::index_counter::*;
 use crate::k2v::causality::*;
-use crate::k2v::counter_table::*;
 use crate::k2v::poll::*;
 
+pub const ENTRIES: &str = "entries";
+pub const CONFLICTS: &str = "conflicts";
+pub const VALUES: &str = "values";
+pub const BYTES: &str = "bytes";
+
 #[derive(PartialEq, Clone, Debug, Serialize, Deserialize)]
 pub struct K2VItem {
 	pub partition: K2VItemPartition,
@@ -112,27 +116,6 @@ impl K2VItem {
 			ent.discard();
 		}
 	}
-
-	// returns counters: (non-deleted entries, conflict entries, non-tombstone values, bytes used)
-	fn stats(&self) -> (i64, i64, i64, i64) {
-		let values = self.values();
-
-		let n_entries = if self.is_tombstone() { 0 } else { 1 };
-		let n_conflicts = if values.len() > 1 { 1 } else { 0 };
-		let n_values = values
-			.iter()
-			.filter(|v| matches!(v, DvvsValue::Value(_)))
-			.count() as i64;
-		let n_bytes = values
-			.iter()
-			.map(|v| match v {
-				DvvsValue::Deleted => 0,
-				DvvsValue::Value(v) => v.len() as i64,
-			})
-			.sum();
-
-		(n_entries, n_conflicts, n_values, n_bytes)
-	}
 }
 
 impl DvvsEntry {
@@ -204,7 +187,7 @@ impl Entry<K2VItemPartition, String> for K2VItem {
 }
 
 pub struct K2VItemTable {
-	pub(crate) counter_table: Arc<IndexCounter<K2VCounterTable>>,
+	pub(crate) counter_table: Arc<IndexCounter<K2VItem>>,
 	pub(crate) subscriptions: Arc<SubscriptionManager>,
 }
 
@@ -229,40 +212,14 @@ impl TableSchema for K2VItemTable {
 		new: Option<&Self::E>,
 	) -> db::TxOpResult<()> {
 		// 1. Count
-		let (old_entries, old_conflicts, old_values, old_bytes) = match old {
-			None => (0, 0, 0, 0),
-			Some(e) => e.stats(),
-		};
-		let (new_entries, new_conflicts, new_values, new_bytes) = match new {
-			None => (0, 0, 0, 0),
-			Some(e) => e.stats(),
-		};
-
-		let count_pk = old
-			.map(|e| e.partition.bucket_id)
-			.unwrap_or_else(|| new.unwrap().partition.bucket_id);
-		let count_sk = old
-			.map(|e| &e.partition.partition_key)
-			.unwrap_or_else(|| &new.unwrap().partition.partition_key);
-
-		let counter_res = self.counter_table.count(
-			tx,
-			&count_pk,
-			count_sk,
-			&[
-				(ENTRIES, new_entries - old_entries),
-				(CONFLICTS, new_conflicts - old_conflicts),
-				(VALUES, new_values - old_values),
-				(BYTES, new_bytes - old_bytes),
-			],
-		);
+		let counter_res = self.counter_table.count(tx, old, new);
 		if let Err(e) = db::unabort(counter_res)? {
 			// This result can be returned by `counter_table.count()` for instance
 			// if messagepack serialization or deserialization fails at some step.
 			// Warn admin but ignore this error for now, that's all we can do.
 			error!(
-				"Unable to update K2V item counter for bucket {:?} partition {}: {}. Index values will be wrong!",
-				count_pk, count_sk, e
+				"Unable to update K2V item counter: {}. Index values will be wrong!",
+				e
 			);
 		}
 
@@ -282,6 +239,47 @@ impl TableSchema for K2VItemTable {
 	}
 }
 
+impl CountedItem for K2VItem {
+	const COUNTER_TABLE_NAME: &'static str = "k2v_index_counter";
+
+	// Partition key = bucket id
+	type CP = Uuid;
+	// Sort key = K2V item's partition key
+	type CS = String;
+
+	fn counter_partition_key(&self) -> &Uuid {
+		&self.partition.bucket_id
+	}
+	fn counter_sort_key(&self) -> &String {
+		&self.partition.partition_key
+	}
+
+	fn counts(&self) -> Vec<(&'static str, i64)> {
+		let values = self.values();
+
+		let n_entries = if self.is_tombstone() { 0 } else { 1 };
+		let n_conflicts = if values.len() > 1 { 1 } else { 0 };
+		let n_values = values
+			.iter()
+			.filter(|v| matches!(v, DvvsValue::Value(_)))
+			.count() as i64;
+		let n_bytes = values
+			.iter()
+			.map(|v| match v {
+				DvvsValue::Deleted => 0,
+				DvvsValue::Value(v) => v.len() as i64,
+			})
+			.sum();
+
+		vec![
+			(ENTRIES, n_entries),
+			(CONFLICTS, n_conflicts),
+			(VALUES, n_values),
+			(BYTES, n_bytes),
+		]
+	}
+}
+
 #[cfg(test)]
 mod tests {
 	use super::*;

src/model/k2v/mod.rs

@@ -1,6 +1,5 @@
 pub mod causality;
 
-pub mod counter_table;
 pub mod item_table;
 
 pub mod poll;