lighthouse/beacon_node/client/src/builder.rs
2020-04-08 16:46:37 +10:00

794 lines
29 KiB
Rust

use crate::config::{ClientGenesis, Config as ClientConfig};
use crate::notifier::spawn_notifier;
use crate::Client;
use beacon_chain::{
builder::{BeaconChainBuilder, Witness},
eth1_chain::{CachingEth1Backend, Eth1Chain},
slot_clock::{SlotClock, SystemTimeSlotClock},
store::{
migrate::{BackgroundMigrator, Migrate, NullMigrator},
DiskStore, MemoryStore, SimpleDiskStore, Store, StoreConfig,
},
BeaconChain, BeaconChainTypes, Eth1ChainBackend, EventHandler,
};
use environment::RuntimeContext;
use eth1::{Config as Eth1Config, Service as Eth1Service};
use eth2_config::Eth2Config;
use eth2_libp2p::NetworkGlobals;
use futures::{future, Future, IntoFuture};
use genesis::{
generate_deterministic_keypairs, interop_genesis_state, state_from_ssz_file, Eth1GenesisService,
};
use lighthouse_bootstrap::Bootstrapper;
use network::{NetworkConfig, NetworkMessage, NetworkService};
use slog::info;
use ssz::Decode;
use std::net::SocketAddr;
use std::path::Path;
use std::sync::Arc;
use std::time::Duration;
use tokio::sync::mpsc::UnboundedSender;
use types::{BeaconState, ChainSpec, EthSpec};
use websocket_server::{Config as WebSocketConfig, WebSocketSender};
/// Interval between polling the eth1 node for genesis information.
pub const ETH1_GENESIS_UPDATE_INTERVAL_MILLIS: u64 = 7_000;
/// Builds a `Client` instance.
///
/// ## Notes
///
/// The builder may start some services (e.g.., libp2p, http server) immediately after they are
/// initialized, _before_ the `self.build(..)` method has been called.
///
/// Types may be elided and the compiler will infer them once all required methods have been
/// called.
///
/// If type inference errors are raised, ensure all necessary components have been initialized. For
/// example, the compiler will be unable to infer `T::Store` unless `self.disk_store(..)` or
/// `self.memory_store(..)` has been called.
pub struct ClientBuilder<T: BeaconChainTypes> {
slot_clock: Option<T::SlotClock>,
store: Option<Arc<T::Store>>,
store_migrator: Option<T::StoreMigrator>,
runtime_context: Option<RuntimeContext<T::EthSpec>>,
chain_spec: Option<ChainSpec>,
beacon_chain_builder: Option<BeaconChainBuilder<T>>,
beacon_chain: Option<Arc<BeaconChain<T>>>,
eth1_service: Option<Eth1Service>,
exit_channels: Vec<tokio::sync::oneshot::Sender<()>>,
event_handler: Option<T::EventHandler>,
network_globals: Option<Arc<NetworkGlobals<T::EthSpec>>>,
network_send: Option<UnboundedSender<NetworkMessage<T::EthSpec>>>,
http_listen_addr: Option<SocketAddr>,
websocket_listen_addr: Option<SocketAddr>,
eth_spec_instance: T::EthSpec,
}
impl<TStore, TStoreMigrator, TSlotClock, TEth1Backend, TEthSpec, TEventHandler>
ClientBuilder<
Witness<TStore, TStoreMigrator, TSlotClock, TEth1Backend, TEthSpec, TEventHandler>,
>
where
TStore: Store<TEthSpec> + 'static,
TStoreMigrator: store::Migrate<TStore, TEthSpec>,
TSlotClock: SlotClock + Clone + 'static,
TEth1Backend: Eth1ChainBackend<TEthSpec, TStore> + 'static,
TEthSpec: EthSpec + 'static,
TEventHandler: EventHandler<TEthSpec> + 'static,
{
/// Instantiates a new, empty builder.
///
/// The `eth_spec_instance` parameter is used to concretize `TEthSpec`.
pub fn new(eth_spec_instance: TEthSpec) -> Self {
Self {
slot_clock: None,
store: None,
store_migrator: None,
runtime_context: None,
chain_spec: None,
beacon_chain_builder: None,
beacon_chain: None,
eth1_service: None,
exit_channels: vec![],
event_handler: None,
network_globals: None,
network_send: None,
http_listen_addr: None,
websocket_listen_addr: None,
eth_spec_instance,
}
}
/// Specifies the runtime context (tokio executor, logger, etc) for client services.
pub fn runtime_context(mut self, context: RuntimeContext<TEthSpec>) -> Self {
self.runtime_context = Some(context);
self
}
/// Specifies the `ChainSpec`.
pub fn chain_spec(mut self, spec: ChainSpec) -> Self {
self.chain_spec = Some(spec);
self
}
/// Initializes the `BeaconChainBuilder`. The `build_beacon_chain` method will need to be
/// called later in order to actually instantiate the `BeaconChain`.
pub fn beacon_chain_builder(
mut self,
client_genesis: ClientGenesis,
config: ClientConfig,
) -> impl Future<Item = Self, Error = String> {
let store = self.store.clone();
let store_migrator = self.store_migrator.take();
let chain_spec = self.chain_spec.clone();
let runtime_context = self.runtime_context.clone();
let eth_spec_instance = self.eth_spec_instance.clone();
let data_dir = config.data_dir.clone();
let disabled_forks = config.disabled_forks.clone();
future::ok(())
.and_then(move |()| {
let store = store
.ok_or_else(|| "beacon_chain_start_method requires a store".to_string())?;
let store_migrator = store_migrator.ok_or_else(|| {
"beacon_chain_start_method requires a store migrator".to_string()
})?;
let context = runtime_context
.ok_or_else(|| {
"beacon_chain_start_method requires a runtime context".to_string()
})?
.service_context("beacon".into());
let spec = chain_spec
.ok_or_else(|| "beacon_chain_start_method requires a chain spec".to_string())?;
let builder = BeaconChainBuilder::new(eth_spec_instance)
.logger(context.log.clone())
.store(store)
.store_migrator(store_migrator)
.data_dir(data_dir)
.custom_spec(spec.clone())
.disabled_forks(disabled_forks);
Ok((builder, spec, context))
})
.and_then(move |(builder, spec, context)| {
let chain_exists = builder
.store_contains_beacon_chain()
.unwrap_or_else(|_| false);
// If the client is expect to resume but there's no beacon chain in the database,
// use the `DepositContract` method. This scenario is quite common when the client
// is shutdown before finding genesis via eth1.
//
// Alternatively, if there's a beacon chain in the database then always resume
// using it.
let client_genesis = if client_genesis == ClientGenesis::Resume && !chain_exists {
info!(context.log, "Defaulting to deposit contract genesis");
ClientGenesis::DepositContract
} else if chain_exists {
ClientGenesis::Resume
} else {
client_genesis
};
let genesis_state_future: Box<dyn Future<Item = _, Error = _> + Send> =
match client_genesis {
ClientGenesis::Interop {
validator_count,
genesis_time,
} => {
let keypairs = generate_deterministic_keypairs(validator_count);
let result = interop_genesis_state(&keypairs, genesis_time, &spec);
let future = result
.and_then(move |genesis_state| builder.genesis_state(genesis_state))
.into_future()
.map(|v| (v, None));
Box::new(future)
}
ClientGenesis::SszFile { path } => {
let result = state_from_ssz_file(path);
let future = result
.and_then(move |genesis_state| builder.genesis_state(genesis_state))
.into_future()
.map(|v| (v, None));
Box::new(future)
}
ClientGenesis::SszBytes {
genesis_state_bytes,
} => {
info!(
context.log,
"Starting from known genesis state";
);
let result = BeaconState::from_ssz_bytes(&genesis_state_bytes)
.map_err(|e| format!("Unable to parse genesis state SSZ: {:?}", e));
let future = result
.and_then(move |genesis_state| builder.genesis_state(genesis_state))
.into_future()
.map(|v| (v, None));
Box::new(future)
}
ClientGenesis::DepositContract => {
info!(
context.log,
"Waiting for eth2 genesis from eth1";
"eth1_node" => &config.eth1.endpoint
);
let genesis_service =
Eth1GenesisService::new(config.eth1, context.log.clone());
let future = genesis_service
.wait_for_genesis_state(
Duration::from_millis(ETH1_GENESIS_UPDATE_INTERVAL_MILLIS),
context.eth2_config().spec.clone(),
)
.and_then(move |genesis_state| builder.genesis_state(genesis_state))
.map(|v| (v, Some(genesis_service.into_core_service())));
Box::new(future)
}
ClientGenesis::RemoteNode { server, .. } => {
let future = Bootstrapper::connect(server, &context.log)
.map_err(|e| {
format!("Failed to initialize bootstrap client: {}", e)
})
.into_future()
.and_then(|bootstrapper| {
let (genesis_state, _genesis_block) =
bootstrapper.genesis().map_err(|e| {
format!("Failed to bootstrap genesis state: {}", e)
})?;
builder.genesis_state(genesis_state)
})
.map(|v| (v, None));
Box::new(future)
}
ClientGenesis::Resume => {
let future = builder.resume_from_db().into_future().map(|v| (v, None));
Box::new(future)
}
};
genesis_state_future
})
.map(move |(beacon_chain_builder, eth1_service_option)| {
self.eth1_service = eth1_service_option;
self.beacon_chain_builder = Some(beacon_chain_builder);
self
})
}
/// Immediately starts the networking stack.
pub fn network(mut self, config: &NetworkConfig) -> Result<Self, String> {
let beacon_chain = self
.beacon_chain
.clone()
.ok_or_else(|| "network requires a beacon chain")?;
let context = self
.runtime_context
.as_ref()
.ok_or_else(|| "network requires a runtime_context")?
.service_context("network".into());
let (network_globals, network_send, network_exit) =
NetworkService::start(beacon_chain, config, &context.executor, context.log)
.map_err(|e| format!("Failed to start network: {:?}", e))?;
self.network_globals = Some(network_globals);
self.network_send = Some(network_send);
self.exit_channels.push(network_exit);
Ok(self)
}
/// Immediately starts the timer service.
fn timer(mut self) -> Result<Self, String> {
let context = self
.runtime_context
.as_ref()
.ok_or_else(|| "node timer requires a runtime_context")?
.service_context("node_timer".into());
let beacon_chain = self
.beacon_chain
.clone()
.ok_or_else(|| "node timer requires a beacon chain")?;
let milliseconds_per_slot = self
.chain_spec
.as_ref()
.ok_or_else(|| "node timer requires a chain spec".to_string())?
.milliseconds_per_slot;
let timer_exit = timer::spawn(
&context.executor,
beacon_chain,
milliseconds_per_slot,
context.log,
)
.map_err(|e| format!("Unable to start node timer: {}", e))?;
self.exit_channels.push(timer_exit);
Ok(self)
}
/// Immediately starts the beacon node REST API http server.
pub fn http_server(
mut self,
client_config: &ClientConfig,
eth2_config: &Eth2Config,
) -> Result<Self, String> {
let beacon_chain = self
.beacon_chain
.clone()
.ok_or_else(|| "http_server requires a beacon chain")?;
let context = self
.runtime_context
.as_ref()
.ok_or_else(|| "http_server requires a runtime_context")?
.service_context("http".into());
let network_globals = self
.network_globals
.clone()
.ok_or_else(|| "http_server requires a libp2p network")?;
let network_send = self
.network_send
.clone()
.ok_or_else(|| "http_server requires a libp2p network sender")?;
let network_info = rest_api::NetworkInfo {
network_globals,
network_chan: network_send,
};
let (exit_channel, listening_addr) = rest_api::start_server(
&client_config.rest_api,
&context.executor,
beacon_chain,
network_info,
client_config
.create_db_path()
.map_err(|_| "unable to read data dir")?,
client_config
.create_freezer_db_path()
.map_err(|_| "unable to read freezer DB dir")?,
eth2_config.clone(),
context.log,
)
.map_err(|e| format!("Failed to start HTTP API: {:?}", e))?;
self.exit_channels.push(exit_channel);
self.http_listen_addr = Some(listening_addr);
Ok(self)
}
/// Immediately starts the service that periodically logs information each slot.
pub fn notifier(mut self) -> Result<Self, String> {
let context = self
.runtime_context
.as_ref()
.ok_or_else(|| "slot_notifier requires a runtime_context")?
.service_context("slot_notifier".into());
let beacon_chain = self
.beacon_chain
.clone()
.ok_or_else(|| "slot_notifier requires a beacon chain")?;
let network_globals = self
.network_globals
.clone()
.ok_or_else(|| "slot_notifier requires a libp2p network")?;
let milliseconds_per_slot = self
.chain_spec
.as_ref()
.ok_or_else(|| "slot_notifier requires a chain spec".to_string())?
.milliseconds_per_slot;
let exit_channel = spawn_notifier(
context,
beacon_chain,
network_globals,
milliseconds_per_slot,
)
.map_err(|e| format!("Unable to start slot notifier: {}", e))?;
self.exit_channels.push(exit_channel);
Ok(self)
}
/// Consumers the builder, returning a `Client` if all necessary components have been
/// specified.
///
/// If type inference errors are being raised, see the comment on the definition of `Self`.
pub fn build(
self,
) -> Client<Witness<TStore, TStoreMigrator, TSlotClock, TEth1Backend, TEthSpec, TEventHandler>>
{
Client {
beacon_chain: self.beacon_chain,
network_globals: self.network_globals,
http_listen_addr: self.http_listen_addr,
websocket_listen_addr: self.websocket_listen_addr,
_exit_channels: self.exit_channels,
}
}
}
impl<TStore, TStoreMigrator, TSlotClock, TEth1Backend, TEthSpec, TEventHandler>
ClientBuilder<
Witness<TStore, TStoreMigrator, TSlotClock, TEth1Backend, TEthSpec, TEventHandler>,
>
where
TStore: Store<TEthSpec> + 'static,
TStoreMigrator: store::Migrate<TStore, TEthSpec>,
TSlotClock: SlotClock + Clone + 'static,
TEth1Backend: Eth1ChainBackend<TEthSpec, TStore> + 'static,
TEthSpec: EthSpec + 'static,
TEventHandler: EventHandler<TEthSpec> + 'static,
{
/// Consumes the internal `BeaconChainBuilder`, attaching the resulting `BeaconChain` to self.
pub fn build_beacon_chain(mut self) -> Result<Self, String> {
let chain = self
.beacon_chain_builder
.ok_or_else(|| "beacon_chain requires a beacon_chain_builder")?
.event_handler(
self.event_handler
.ok_or_else(|| "beacon_chain requires an event handler")?,
)
.slot_clock(
self.slot_clock
.clone()
.ok_or_else(|| "beacon_chain requires a slot clock")?,
)
.reduced_tree_fork_choice()
.map_err(|e| format!("Failed to init fork choice: {}", e))?
.build()
.map_err(|e| format!("Failed to build beacon chain: {}", e))?;
self.beacon_chain = Some(Arc::new(chain));
self.beacon_chain_builder = None;
self.event_handler = None;
// a beacon chain requires a timer
self.timer()
}
}
impl<TStore, TStoreMigrator, TSlotClock, TEth1Backend, TEthSpec>
ClientBuilder<
Witness<
TStore,
TStoreMigrator,
TSlotClock,
TEth1Backend,
TEthSpec,
WebSocketSender<TEthSpec>,
>,
>
where
TStore: Store<TEthSpec> + 'static,
TStoreMigrator: store::Migrate<TStore, TEthSpec>,
TSlotClock: SlotClock + 'static,
TEth1Backend: Eth1ChainBackend<TEthSpec, TStore> + 'static,
TEthSpec: EthSpec + 'static,
{
/// Specifies that the `BeaconChain` should publish events using the WebSocket server.
pub fn websocket_event_handler(mut self, config: WebSocketConfig) -> Result<Self, String> {
let context = self
.runtime_context
.as_ref()
.ok_or_else(|| "websocket_event_handler requires a runtime_context")?
.service_context("ws".into());
let (sender, exit_channel, listening_addr): (
WebSocketSender<TEthSpec>,
Option<_>,
Option<_>,
) = if config.enabled {
let (sender, exit, listening_addr) =
websocket_server::start_server(&config, &context.executor, &context.log)?;
(sender, Some(exit), Some(listening_addr))
} else {
(WebSocketSender::dummy(), None, None)
};
if let Some(channel) = exit_channel {
self.exit_channels.push(channel);
}
self.event_handler = Some(sender);
self.websocket_listen_addr = listening_addr;
Ok(self)
}
}
impl<TStoreMigrator, TSlotClock, TEth1Backend, TEthSpec, TEventHandler>
ClientBuilder<
Witness<
DiskStore<TEthSpec>,
TStoreMigrator,
TSlotClock,
TEth1Backend,
TEthSpec,
TEventHandler,
>,
>
where
TSlotClock: SlotClock + 'static,
TStoreMigrator: store::Migrate<DiskStore<TEthSpec>, TEthSpec> + 'static,
TEth1Backend: Eth1ChainBackend<TEthSpec, DiskStore<TEthSpec>> + 'static,
TEthSpec: EthSpec + 'static,
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,
config: StoreConfig,
) -> Result<Self, String> {
let context = self
.runtime_context
.as_ref()
.ok_or_else(|| "disk_store requires a log".to_string())?
.service_context("freezer_db".into());
let spec = self
.chain_spec
.clone()
.ok_or_else(|| "disk_store requires a chain spec".to_string())?;
let store = DiskStore::open(hot_path, cold_path, config, spec, context.log)
.map_err(|e| format!("Unable to open database: {:?}", e))?;
self.store = Some(Arc::new(store));
Ok(self)
}
}
impl<TStoreMigrator, TSlotClock, TEth1Backend, TEthSpec, TEventHandler>
ClientBuilder<
Witness<
SimpleDiskStore<TEthSpec>,
TStoreMigrator,
TSlotClock,
TEth1Backend,
TEthSpec,
TEventHandler,
>,
>
where
TSlotClock: SlotClock + 'static,
TStoreMigrator: store::Migrate<SimpleDiskStore<TEthSpec>, TEthSpec> + 'static,
TEth1Backend: Eth1ChainBackend<TEthSpec, SimpleDiskStore<TEthSpec>> + 'static,
TEthSpec: EthSpec + 'static,
TEventHandler: EventHandler<TEthSpec> + 'static,
{
/// Specifies that the `Client` should use a `DiskStore` database.
pub fn simple_disk_store(mut self, path: &Path) -> Result<Self, String> {
let store =
SimpleDiskStore::open(path).map_err(|e| format!("Unable to open database: {:?}", e))?;
self.store = Some(Arc::new(store));
Ok(self)
}
}
impl<TSlotClock, TEth1Backend, TEthSpec, TEventHandler>
ClientBuilder<
Witness<
MemoryStore<TEthSpec>,
NullMigrator,
TSlotClock,
TEth1Backend,
TEthSpec,
TEventHandler,
>,
>
where
TSlotClock: SlotClock + 'static,
TEth1Backend: Eth1ChainBackend<TEthSpec, MemoryStore<TEthSpec>> + 'static,
TEthSpec: EthSpec + 'static,
TEventHandler: EventHandler<TEthSpec> + 'static,
{
/// Specifies that the `Client` should use a `MemoryStore` database.
///
/// Also sets the `store_migrator` to the `NullMigrator`, as that's the only viable choice.
pub fn memory_store(mut self) -> Self {
let store = MemoryStore::open();
self.store = Some(Arc::new(store));
self.store_migrator = Some(NullMigrator);
self
}
}
impl<TSlotClock, TEth1Backend, TEthSpec, TEventHandler>
ClientBuilder<
Witness<
DiskStore<TEthSpec>,
BackgroundMigrator<TEthSpec>,
TSlotClock,
TEth1Backend,
TEthSpec,
TEventHandler,
>,
>
where
TSlotClock: SlotClock + 'static,
TEth1Backend: Eth1ChainBackend<TEthSpec, DiskStore<TEthSpec>> + 'static,
TEthSpec: EthSpec + 'static,
TEventHandler: EventHandler<TEthSpec> + 'static,
{
pub fn background_migrator(mut self) -> Result<Self, String> {
let store = self.store.clone().ok_or_else(|| {
"background_migrator requires the store to be initialized".to_string()
})?;
self.store_migrator = Some(BackgroundMigrator::new(store));
Ok(self)
}
}
impl<TStore, TStoreMigrator, TSlotClock, TEthSpec, TEventHandler>
ClientBuilder<
Witness<
TStore,
TStoreMigrator,
TSlotClock,
CachingEth1Backend<TEthSpec, TStore>,
TEthSpec,
TEventHandler,
>,
>
where
TStore: Store<TEthSpec> + 'static,
TStoreMigrator: store::Migrate<TStore, TEthSpec>,
TSlotClock: SlotClock + 'static,
TEthSpec: EthSpec + 'static,
TEventHandler: EventHandler<TEthSpec> + 'static,
{
/// Specifies that the `BeaconChain` should cache eth1 blocks/logs from a remote eth1 node
/// (e.g., Parity/Geth) and refer to that cache when collecting deposits or eth1 votes during
/// block production.
pub fn caching_eth1_backend(mut self, config: Eth1Config) -> Result<Self, String> {
let context = self
.runtime_context
.as_ref()
.ok_or_else(|| "caching_eth1_backend requires a runtime_context")?
.service_context("eth1_rpc".into());
let beacon_chain_builder = self
.beacon_chain_builder
.ok_or_else(|| "caching_eth1_backend requires a beacon_chain_builder")?;
let store = self
.store
.clone()
.ok_or_else(|| "caching_eth1_backend requires a store".to_string())?;
let backend = if let Some(eth1_service_from_genesis) = self.eth1_service {
eth1_service_from_genesis.update_config(config)?;
// This cache is not useful because it's first (earliest) block likely the block that
// triggered genesis.
//
// In order to vote we need to be able to go back at least 2 * `ETH1_FOLLOW_DISTANCE`
// from the genesis-triggering block. Presently the block cache does not support
// importing blocks with decreasing block numbers, it only accepts them in increasing
// order. If this turns out to be a bottleneck we can update the block cache to allow
// adding earlier blocks too.
eth1_service_from_genesis.drop_block_cache();
CachingEth1Backend::from_service(eth1_service_from_genesis, store)
} else {
beacon_chain_builder
.get_persisted_eth1_backend()?
.map(|persisted| {
Eth1Chain::from_ssz_container(
&persisted,
config.clone(),
store.clone(),
&context.log,
)
.map(|chain| chain.into_backend())
})
.unwrap_or_else(|| {
Ok(CachingEth1Backend::new(config, context.log.clone(), store))
})?
};
self.eth1_service = None;
let exit = {
let (tx, rx) = tokio::sync::oneshot::channel();
self.exit_channels.push(tx);
rx
};
// Starts the service that connects to an eth1 node and periodically updates caches.
context.executor.spawn(backend.start(exit));
self.beacon_chain_builder = Some(beacon_chain_builder.eth1_backend(Some(backend)));
Ok(self)
}
/// Do not use any eth1 backend. The client will not be able to produce beacon blocks.
pub fn no_eth1_backend(mut self) -> Result<Self, String> {
let beacon_chain_builder = self
.beacon_chain_builder
.ok_or_else(|| "caching_eth1_backend requires a beacon_chain_builder")?;
self.beacon_chain_builder = Some(beacon_chain_builder.no_eth1_backend());
Ok(self)
}
/// Use an eth1 backend that can produce blocks but is not connected to an Eth1 node.
///
/// This backend will never produce deposits so it's impossible to add validators after
/// genesis. The `Eth1Data` votes will be deterministic junk data.
///
/// ## Notes
///
/// The client is given the `CachingEth1Backend` type, but the http backend is never started and the
/// caches are never used.
pub fn dummy_eth1_backend(mut self) -> Result<Self, String> {
let beacon_chain_builder = self
.beacon_chain_builder
.ok_or_else(|| "caching_eth1_backend requires a beacon_chain_builder")?;
self.beacon_chain_builder = Some(beacon_chain_builder.dummy_eth1_backend()?);
Ok(self)
}
}
impl<TStore, TStoreMigrator, TEth1Backend, TEthSpec, TEventHandler>
ClientBuilder<
Witness<TStore, TStoreMigrator, SystemTimeSlotClock, TEth1Backend, TEthSpec, TEventHandler>,
>
where
TStore: Store<TEthSpec> + 'static,
TStoreMigrator: store::Migrate<TStore, TEthSpec>,
TEth1Backend: Eth1ChainBackend<TEthSpec, TStore> + 'static,
TEthSpec: EthSpec + 'static,
TEventHandler: EventHandler<TEthSpec> + 'static,
{
/// Specifies that the slot clock should read the time from the computers system clock.
pub fn system_time_slot_clock(mut self) -> Result<Self, String> {
let beacon_chain_builder = self
.beacon_chain_builder
.as_ref()
.ok_or_else(|| "system_time_slot_clock requires a beacon_chain_builder")?;
let genesis_time = beacon_chain_builder
.finalized_snapshot
.as_ref()
.ok_or_else(|| "system_time_slot_clock requires an initialized beacon state")?
.beacon_state
.genesis_time;
let spec = self
.chain_spec
.clone()
.ok_or_else(|| "system_time_slot_clock requires a chain spec".to_string())?;
let slot_clock = SystemTimeSlotClock::new(
spec.genesis_slot,
Duration::from_secs(genesis_time),
Duration::from_millis(spec.milliseconds_per_slot),
);
self.slot_clock = Some(slot_clock);
Ok(self)
}
}