Improve freezer DB efficiency with periodic restore points (#649)

* Draft of checkpoint freezer DB

* Fix bugs

* Adjust root iterators for checkpoint database

* Fix freezer state lookups with no slot hint

* Fix split comment

* Use "restore point" to refer to frozen states

* Resolve some FIXMEs

* Configurable slots per restore point

* Document new freezer DB functions

* Fix up StoreConfig

* Fix new test for merge

* Document SPRP default CLI flag, clarify tests

beacon_node/client/src/builder.rs

@@ -577,7 +577,12 @@ where
     TEventHandler: EventHandler<TEthSpec> + 'static,
 {
     /// Specifies that the `Client` should use a `DiskStore` database.
-    pub fn disk_store(mut self, hot_path: &Path, cold_path: &Path) -> Result<Self, String> {
+    pub fn disk_store(
+        mut self,
+        hot_path: &Path,
+        cold_path: &Path,
+        slots_per_restore_point: u64,
+    ) -> Result<Self, String> {
         let context = self
             .runtime_context
             .as_ref()
@@ -588,8 +593,14 @@ where
             .clone()
             .ok_or_else(|| "disk_store requires a chain spec".to_string())?;
 
-        let store = DiskStore::open(hot_path, cold_path, spec, context.log)
-            .map_err(|e| format!("Unable to open database: {:?}", e).to_string())?;
+        let store = DiskStore::open::<TEthSpec>(
+            hot_path,
+            cold_path,
+            slots_per_restore_point,
+            spec,
+            context.log,
+        )
+        .map_err(|e| format!("Unable to open database: {:?}", e).to_string())?;
         self.store = Some(Arc::new(store));
         Ok(self)
     }

beacon_node/client/src/config.rs

@@ -6,9 +6,6 @@ use std::path::PathBuf;
 /// The number initial validators when starting the `Minimal`.
 const TESTNET_SPEC_CONSTANTS: &str = "minimal";
 
-/// Default directory name for the freezer database under the top-level data dir.
-const DEFAULT_FREEZER_DB_DIR: &str = "freezer_db";
-
 /// Defines how the client should initialize the `BeaconChain` and other components.
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub enum ClientGenesis {
@@ -45,9 +42,6 @@ impl Default for ClientGenesis {
 pub struct Config {
     pub data_dir: PathBuf,
     pub testnet_dir: Option<PathBuf>,
-    pub db_type: String,
-    pub db_name: String,
-    pub freezer_db_path: Option<PathBuf>,
     pub log_file: PathBuf,
     pub spec_constants: String,
     /// If true, the node will use co-ordinated junk for eth1 values.
@@ -59,6 +53,7 @@ pub struct Config {
     /// The `genesis` field is not serialized or deserialized by `serde` to ensure it is defined
     /// via the CLI at runtime, instead of from a configuration file saved to disk.
     pub genesis: ClientGenesis,
+    pub store: store::StoreConfig,
     pub network: network::NetworkConfig,
     pub rest_api: rest_api::Config,
     pub websocket_server: websocket_server::Config,
@@ -71,10 +66,8 @@ impl Default for Config {
             data_dir: PathBuf::from(".lighthouse"),
             testnet_dir: None,
             log_file: PathBuf::from(""),
-            db_type: "disk".to_string(),
-            db_name: "chain_db".to_string(),
-            freezer_db_path: None,
             genesis: <_>::default(),
+            store: <_>::default(),
             network: NetworkConfig::default(),
             rest_api: <_>::default(),
             websocket_server: <_>::default(),
@@ -90,7 +83,7 @@ impl Config {
     /// Get the database path without initialising it.
     pub fn get_db_path(&self) -> Option<PathBuf> {
         self.get_data_dir()
-            .map(|data_dir| data_dir.join(&self.db_name))
+            .map(|data_dir| data_dir.join(&self.store.db_name))
     }
 
     /// Get the database path, creating it if necessary.
@@ -104,7 +97,7 @@ impl Config {
     /// Fetch default path to use for the freezer database.
     fn default_freezer_db_path(&self) -> Option<PathBuf> {
         self.get_data_dir()
-            .map(|data_dir| data_dir.join(DEFAULT_FREEZER_DB_DIR))
+            .map(|data_dir| data_dir.join(self.store.default_freezer_db_dir()))
     }
 
     /// Returns the path to which the client may initialize the on-disk freezer database.
@@ -112,7 +105,8 @@ impl Config {
     /// Will attempt to use the user-supplied path from e.g. the CLI, or will default
     /// to a directory in the data_dir if no path is provided.
     pub fn get_freezer_db_path(&self) -> Option<PathBuf> {
-        self.freezer_db_path
+        self.store
+            .freezer_db_path
             .clone()
             .or_else(|| self.default_freezer_db_path())
     }