Introduce API for directly importing the state into the database

substrate/client/api/src/backend.rs

@@ -235,6 +235,9 @@ pub trait BlockImportOperation<Block: BlockT> {
 
 	/// Configure whether to create a block gap if newly imported block is missing parent
 	fn set_create_gap(&mut self, create_gap: bool);
+
+	/// Configure whether to commit the state changes to the underlying database.
+	fn set_commit_state(&mut self, commit: bool);
 }
 
 /// Interface for performing operations on the backend.
@@ -590,6 +593,27 @@ pub trait Backend<Block: BlockT>: AuxStore + Send + Sync {
 	/// Returns state backend with post-state of given block.
 	fn state_at(&self, hash: Block::Hash) -> sp_blockchain::Result<Self::State>;
 
+	/// Import the state changes directly to the database.
+	///
+	/// # Arguments
+	///
+	/// - `at`: The block hash corresponding to the last available state before updating the trie
+	///   database.
+	/// - `storage`: The storage changes reflecting the transition from the last local state to the
+	///   target block's state being imported.
+	/// - `state_version`: The state version of the target block, which is resolved from the
+	///   provided `storage` data.
+	///
+	/// # Returns
+	///
+	/// Returns the state root after importing the state.
+	fn import_state(
+		&self,
+		at: Block::Hash,
+		storage: sp_runtime::Storage,
+		state_version: sp_runtime::StateVersion,
+	) -> sp_blockchain::Result<Block::Hash>;
+
 	/// Attempts to revert the chain by `n` blocks. If `revert_finalized` is set it will attempt to
 	/// revert past any finalized block, this is unsafe and can potentially leave the node in an
 	/// inconsistent state. All blocks higher than the best block are also reverted and not counting

substrate/client/api/src/in_mem.rs

@@ -192,7 +192,7 @@ impl<Block: BlockT> Blockchain<Block> {
 	pub fn equals_to(&self, other: &Self) -> bool {
 		// Check ptr equality first to avoid double read locks.
 		if ptr::eq(self, other) {
-			return true
+			return true;
 		}
 		self.canon_equals_to(other) && self.storage.read().blocks == other.storage.read().blocks
 	}
@@ -201,7 +201,7 @@ impl<Block: BlockT> Blockchain<Block> {
 	pub fn canon_equals_to(&self, other: &Self) -> bool {
 		// Check ptr equality first to avoid double read locks.
 		if ptr::eq(self, other) {
-			return true
+			return true;
 		}
 		let this = self.storage.read();
 		let other = other.storage.read();
@@ -307,7 +307,7 @@ impl<Block: BlockT> Blockchain<Block> {
 			if !stored_justifications.append(justification) {
 				return Err(sp_blockchain::Error::BadJustification(
 					"Duplicate consensus engine ID".into(),
-				))
+				));
 			}
 		} else {
 			*block_justifications = Some(Justifications::from(justification));
@@ -586,6 +586,8 @@ impl<Block: BlockT> backend::BlockImportOperation<Block> for BlockImportOperatio
 	}
 
 	fn set_create_gap(&mut self, _create_gap: bool) {}
+
+	fn set_commit_state(&mut self, _commit: bool) {}
 }
 
 /// In-memory backend. Keeps all states and blocks in memory.
@@ -736,7 +738,7 @@ impl<Block: BlockT> backend::Backend<Block> for Backend<Block> {
 
 	fn state_at(&self, hash: Block::Hash) -> sp_blockchain::Result<Self::State> {
 		if hash == Default::default() {
-			return Ok(Self::State::default())
+			return Ok(Self::State::default());
 		}
 
 		self.states
@@ -746,6 +748,15 @@ impl<Block: BlockT> backend::Backend<Block> for Backend<Block> {
 			.ok_or_else(|| sp_blockchain::Error::UnknownBlock(format!("{}", hash)))
 	}
 
+	fn import_state(
+		&self,
+		_at: Block::Hash,
+		_storage: sp_runtime::Storage,
+		_state_version: sp_runtime::StateVersion,
+	) -> sp_blockchain::Result<Block::Hash> {
+		unimplemented!("Not needed for in-mem backend")
+	}
+
 	fn revert(
 		&self,
 		_n: NumberFor<Block>,
@@ -783,15 +794,15 @@ impl<Block: BlockT> backend::LocalBackend<Block> for Backend<Block> {}
 /// Check that genesis storage is valid.
 pub fn check_genesis_storage(storage: &Storage) -> sp_blockchain::Result<()> {
 	if storage.top.iter().any(|(k, _)| well_known_keys::is_child_storage_key(k)) {
-		return Err(sp_blockchain::Error::InvalidState)
+		return Err(sp_blockchain::Error::InvalidState);
 	}
 
 	if storage
 		.children_default
 		.keys()
 		.any(|child_key| !well_known_keys::is_child_storage_key(child_key))
 	{
-		return Err(sp_blockchain::Error::InvalidState)
+		return Err(sp_blockchain::Error::InvalidState);
 	}
 
 	Ok(())

substrate/client/db/Cargo.toml

@@ -36,6 +36,7 @@ sp-core = { workspace = true, default-features = true }
 sp-database = { workspace = true, default-features = true }
 sp-runtime = { workspace = true, default-features = true }
 sp-state-machine = { workspace = true, default-features = true }
+sp-storage = { workspace = true, default-features = true }
 sp-trie = { workspace = true, default-features = true }
 
 [dev-dependencies]