Replace AuxStore with custom RocksDB (#2471)

* Use KeyValueDB in approval-voting

* use KVDB instead of AuxStore

* add rocksdb to cargo toml

* add a Config struct

* create new DB in service

* fix dep for regular node

* make optional

* post merge fix

Co-authored-by: Andronik Ordian <write@reusable.software>

polkadot/node/service/src/lib.rs

@@ -29,6 +29,7 @@ use {
 	tracing::info,
 	polkadot_node_core_av_store::Config as AvailabilityConfig,
 	polkadot_node_core_av_store::Error as AvailabilityError,
+	polkadot_node_core_approval_voting::Config as ApprovalVotingConfig,
 	polkadot_node_core_proposer::ProposerFactory,
 	polkadot_overseer::{AllSubsystems, BlockInfo, Overseer, OverseerHandler},
 	polkadot_primitives::v1::ParachainHost,
@@ -137,6 +138,10 @@ pub enum Error {
 
 	#[error("Authorities require the real overseer implementation")]
 	AuthoritiesRequireRealOverseer,
+
+	#[cfg(feature = "full-node")]
+	#[error("Creating a custom database is required for validators")]
+	DatabasePathRequired,
 }
 
 /// Can be called for a `Configuration` to check if it is a configuration for the `Kusama` network.
@@ -358,7 +363,7 @@ fn real_overseer<Spawner, RuntimeClient>(
 	spawner: Spawner,
 	_: IsCollator,
 	_: IsolationStrategy,
-	_: u64,
+	_: ApprovalVotingConfig,
 ) -> Result<(Overseer<Spawner>, OverseerHandler), Error>
 where
 	RuntimeClient: 'static + ProvideRuntimeApi<Block> + HeaderBackend<Block> + AuxStore,
@@ -386,7 +391,7 @@ fn real_overseer<Spawner, RuntimeClient>(
 	spawner: Spawner,
 	is_collator: IsCollator,
 	isolation_strategy: IsolationStrategy,
-	slot_duration: u64,
+	approval_voting_config: ApprovalVotingConfig,
 ) -> Result<(Overseer<Spawner>, OverseerHandler), Error>
 where
 	RuntimeClient: 'static + ProvideRuntimeApi<Block> + HeaderBackend<Block> + AuxStore,
@@ -417,7 +422,7 @@ where
 	use polkadot_node_core_approval_voting::ApprovalVotingSubsystem;
 
 	#[cfg(not(feature = "approval-checking"))]
-	let _ = slot_duration; // silence.
+	let _ = approval_voting_config; // silence.
 
 	let all_subsystems = AllSubsystems {
 		availability_distribution: AvailabilityDistributionSubsystem::new(
@@ -494,11 +499,10 @@ where
 			Metrics::register(registry)?,
 		),
 		#[cfg(feature = "approval-checking")]
-		approval_voting: ApprovalVotingSubsystem::new(
+		approval_voting: ApprovalVotingSubsystem::with_config(
+			approval_voting_config,
 			keystore.clone(),
-			slot_duration,
-			runtime_client.clone(),
-		),
+		)?,
 		#[cfg(not(feature = "approval-checking"))]
 		approval_voting: polkadot_subsystem::DummySubsystem,
 	};
@@ -656,6 +660,14 @@ pub fn new_full<RuntimeApi, Executor>(
 
 	let availability_config = config.database.clone().try_into().map_err(Error::Availability)?;
 
+	let approval_voting_config = ApprovalVotingConfig {
+		path: config.database.path()
+			.ok_or(Error::DatabasePathRequired)?
+			.join("parachains").join("approval-voting"),
+		slot_duration_millis: slot_duration,
+		cache_size: None, // default is fine.
+	};
+
 	let telemetry_span = TelemetrySpan::new();
 	let _telemetry_span_entered = telemetry_span.enter();
 
@@ -749,7 +761,7 @@ pub fn new_full<RuntimeApi, Executor>(
 			spawner,
 			is_collator,
 			isolation_strategy,
-			slot_duration,
+			approval_voting_config,
 		)?;
 		let overseer_handler_clone = overseer_handler.clone();