Start LMDB adapter, with fixed semantics

3 files changed, 40 insertions, 37 deletions

diff --git a/src/table/data.rs b/src/table/data.rs
index 17402bb6..cca96f68 100644
--- a/src/table/data.rs
+++ b/src/table/data.rs
@@ -182,7 +182,7 @@ where
 		tree_key: &[u8],
 		f: impl Fn(Option<F::E>) -> F::E,
 	) -> Result<Option<F::E>, Error> {
-		let changed = self.store.db().transaction(|tx| {
+		let changed = self.store.db().transaction(|mut tx| {
 			let (old_entry, old_bytes, new_entry) = match tx.get(&self.store, tree_key)? {
 				Some(old_bytes) => {
 					let old_entry = self.decode_entry(&old_bytes).map_err(db::TxError::Abort)?;
@@ -203,6 +203,7 @@ where
 				.map_err(Error::RmpEncode)
 				.map_err(db::TxError::Abort)?;
 			let encoding_changed = Some(&new_bytes[..]) != old_bytes.as_ref().map(|x| &x[..]);
+			drop(old_bytes);
 
 			if value_changed || encoding_changed {
 				let new_bytes_hash = blake2sum(&new_bytes[..]);
@@ -241,15 +242,16 @@ where
 	}
 
 	pub(crate) fn delete_if_equal(self: &Arc<Self>, k: &[u8], v: &[u8]) -> Result<bool, Error> {
-		let removed = self.store.db().transaction(|tx| {
-			if let Some(cur_v) = tx.get(&self.store, k)? {
-				if cur_v == v {
-					tx.remove(&self.store, k)?;
-					tx.insert(&self.merkle_todo, k, vec![])?;
-					return Ok(true);
-				}
+		let removed = self.store.db().transaction(|mut tx| {
+			let remove = match tx.get(&self.store, k)? {
+				Some(cur_v) if cur_v == v => true,
+				_ => false,
+			};
+			if remove {
+				tx.remove(&self.store, k)?;
+				tx.insert(&self.merkle_todo, k, vec![])?;
 			}
-			Ok(false)
+			Ok(remove)
 		})?;
 
 		if removed {
@@ -267,15 +269,16 @@ where
 		k: &[u8],
 		vhash: Hash,
 	) -> Result<bool, Error> {
-		let removed = self.store.db().transaction(|tx| {
-			if let Some(cur_v) = tx.get(&self.store, k)? {
-				if blake2sum(&cur_v[..]) == vhash {
-					tx.remove(&self.store, k)?;
-					tx.insert(&self.merkle_todo, k, vec![])?;
-					return Ok(Some(cur_v.into_vec()));
-				}
+		let removed = self.store.db().transaction(|mut tx| {
+			let remove_v = match tx.get(&self.store, k)? {
+				Some(cur_v) if blake2sum(&cur_v[..]) == vhash => Some(cur_v.into_vec()),
+				_ => None,
+			};
+			if remove_v.is_some() {
+				tx.remove(&self.store, k)?;
+				tx.insert(&self.merkle_todo, k, vec![])?;
 			}
-			Ok(None)
+			Ok(remove_v)
 		})?;
 
 		if let Some(old_v) = removed {
diff --git a/src/table/gc.rs b/src/table/gc.rs
index 260fecfa..e2611389 100644
--- a/src/table/gc.rs
+++ b/src/table/gc.rs
@@ -376,13 +376,13 @@ impl GcTodoEntry {
 	/// what we have to do is still the same
 	pub(crate) fn remove_if_equal(&self, gc_todo_tree: &db::Tree) -> Result<(), Error> {
 		let key = self.todo_table_key();
-		gc_todo_tree.db().transaction(|tx| {
-			let old_val = tx.get(gc_todo_tree, &key)?;
-			match old_val {
-				Some(ov) if ov == self.value_hash.as_slice() => {
-					tx.remove(gc_todo_tree, &key)?;
-				}
-				_ => (),
+		gc_todo_tree.db().transaction(|mut tx| {
+			let remove = match tx.get(gc_todo_tree, &key)? {
+				Some(ov) if ov == self.value_hash.as_slice() => true,
+				_ => false,
+			};
+			if remove {
+				tx.remove(gc_todo_tree, &key)?;
 			}
 			tx.commit(())
 		})?;
diff --git a/src/table/merkle.rs b/src/table/merkle.rs
index 8c574d09..92e1445b 100644
--- a/src/table/merkle.rs
+++ b/src/table/merkle.rs
@@ -137,17 +137,17 @@ where
 		self.data
 			.merkle_tree
 			.db()
-			.transaction(|tx| self.update_item_rec(tx, k, &khash, &key, new_vhash))?;
-
-		let deleted = self.data.merkle_todo.db().transaction(|tx| {
-			let old_val = tx.get(&self.data.merkle_todo, k)?;
-			match old_val {
-				Some(ov) if ov == vhash_by => {
-					tx.remove(&self.data.merkle_todo, k)?;
-					tx.commit(true)
-				}
-				_ => tx.commit(false),
+			.transaction(|mut tx| self.update_item_rec(&mut tx, k, &khash, &key, new_vhash))?;
+
+		let deleted = self.data.merkle_todo.db().transaction(|mut tx| {
+			let remove = match tx.get(&self.data.merkle_todo, k)? {
+				Some(ov) if ov == vhash_by => true,
+				_ => false,
+			};
+			if remove {
+				tx.remove(&self.data.merkle_todo, k)?;
 			}
+			Ok(remove)
 		})?;
 
 		if !deleted {
@@ -162,7 +162,7 @@ where
 
 	fn update_item_rec(
 		&self,
-		tx: db::Transaction<'_>,
+		tx: &mut db::Transaction<'_>,
 		k: &[u8],
 		khash: &Hash,
 		key: &MerkleNodeKey,
@@ -288,7 +288,7 @@ where
 
 	fn read_node_txn(
 		&self,
-		tx: db::Transaction<'_>,
+		tx: &mut db::Transaction<'_>,
 		k: &MerkleNodeKey,
 	) -> db::TxResult<MerkleNode, Error> {
 		let ent = tx.get(&self.data.merkle_tree, k.encode())?;
@@ -297,7 +297,7 @@ where
 
 	fn put_node_txn(
 		&self,
-		tx: db::Transaction<'_>,
+		tx: &mut db::Transaction<'_>,
 		k: &MerkleNodeKey,
 		v: &MerkleNode,
 	) -> db::TxResult<Hash, Error> {