perf(kv): dont retrieve values for write ops

see https://git.deuxfleurs.fr/Deuxfleurs/garage/issues/851

3 files changed, 14 insertions, 24 deletions

diff --git a/src/db/lib.rs b/src/db/lib.rs
index c8f9e13f..d6057505 100644
--- a/src/db/lib.rs
+++ b/src/db/lib.rs
@@ -211,16 +211,12 @@ impl Tree {
 
 	/// Returns the old value if there was one
 	#[inline]
-	pub fn insert<T: AsRef<[u8]>, U: AsRef<[u8]>>(
-		&self,
-		key: T,
-		value: U,
-	) -> Result<Option<Value>> {
+	pub fn insert<T: AsRef<[u8]>, U: AsRef<[u8]>>(&self, key: T, value: U) -> Result<()> {
 		self.0.insert(self.1, key.as_ref(), value.as_ref())
 	}
 	/// Returns the old value if there was one
 	#[inline]
-	pub fn remove<T: AsRef<[u8]>>(&self, key: T) -> Result<Option<Value>> {
+	pub fn remove<T: AsRef<[u8]>>(&self, key: T) -> Result<()> {
 		self.0.remove(self.1, key.as_ref())
 	}
 	/// Clears all values from the tree
@@ -339,8 +335,8 @@ pub(crate) trait IDb: Send + Sync {
 	fn get(&self, tree: usize, key: &[u8]) -> Result<Option<Value>>;
 	fn len(&self, tree: usize) -> Result<usize>;
 
-	fn insert(&self, tree: usize, key: &[u8], value: &[u8]) -> Result<Option<Value>>;
-	fn remove(&self, tree: usize, key: &[u8]) -> Result<Option<Value>>;
+	fn insert(&self, tree: usize, key: &[u8], value: &[u8]) -> Result<()>;
+	fn remove(&self, tree: usize, key: &[u8]) -> Result<()>;
 	fn clear(&self, tree: usize) -> Result<()>;
 
 	fn iter(&self, tree: usize) -> Result<ValueIter<'_>>;
diff --git a/src/db/lmdb_adapter.rs b/src/db/lmdb_adapter.rs
index d5066664..436a67fa 100644
--- a/src/db/lmdb_adapter.rs
+++ b/src/db/lmdb_adapter.rs
@@ -132,22 +132,20 @@ impl IDb for LmdbDb {
 		Ok(tree.len(&tx)?.try_into().unwrap())
 	}
 
-	fn insert(&self, tree: usize, key: &[u8], value: &[u8]) -> Result<Option<Value>> {
+	fn insert(&self, tree: usize, key: &[u8], value: &[u8]) -> Result<()> {
 		let tree = self.get_tree(tree)?;
 		let mut tx = self.db.write_txn()?;
-		let old_val = tree.get(&tx, key)?.map(Vec::from);
 		tree.put(&mut tx, key, value)?;
 		tx.commit()?;
-		Ok(old_val)
+		Ok(())
 	}
 
-	fn remove(&self, tree: usize, key: &[u8]) -> Result<Option<Value>> {
+	fn remove(&self, tree: usize, key: &[u8]) -> Result<()> {
 		let tree = self.get_tree(tree)?;
 		let mut tx = self.db.write_txn()?;
-		let old_val = tree.get(&tx, key)?.map(Vec::from);
 		tree.delete(&mut tx, key)?;
 		tx.commit()?;
-		Ok(old_val)
+		Ok(())
 	}
 
 	fn clear(&self, tree: usize) -> Result<()> {
diff --git a/src/db/sqlite_adapter.rs b/src/db/sqlite_adapter.rs
index a91b9011..eb106a31 100644
--- a/src/db/sqlite_adapter.rs
+++ b/src/db/sqlite_adapter.rs
@@ -169,7 +169,7 @@ impl IDb for SqliteDb {
 		}
 	}
 
-	fn insert(&self, tree: usize, key: &[u8], value: &[u8]) -> Result<Option<Value>> {
+	fn insert(&self, tree: usize, key: &[u8], value: &[u8]) -> Result<()> {
 		let tree = self.get_tree(tree)?;
 		let db = self.db.get()?;
 		let lock = self.write_lock.lock();
@@ -184,23 +184,19 @@ impl IDb for SqliteDb {
 		assert_eq!(n, 1);
 
 		drop(lock);
-		Ok(old_val)
+		Ok(())
 	}
 
-	fn remove(&self, tree: usize, key: &[u8]) -> Result<Option<Value>> {
+	fn remove(&self, tree: usize, key: &[u8]) -> Result<()> {
 		let tree = self.get_tree(tree)?;
 		let db = self.db.get()?;
 		let lock = self.write_lock.lock();
 
-		let old_val = self.internal_get(&db, &tree, key)?;
-
-		if old_val.is_some() {
-			let n = db.execute(&format!("DELETE FROM {} WHERE k = ?1", tree), params![key])?;
-			assert_eq!(n, 1);
-		}
+		let n = db.execute(&format!("DELETE FROM {} WHERE k = ?1", tree), params![key])?;
+		assert_eq!(n, 1);
 
 		drop(lock);
-		Ok(old_val)
+		Ok(())
 	}
 
 	fn clear(&self, tree: usize) -> Result<()> {