Remove sync crate, move into network crate

beacon_node/network/src/sync/mod.rs

@@ -0,0 +1,11 @@
+/// Syncing for lighthouse.
+///
+/// Stores the various syncing methods for the beacon chain.
+mod simple_sync;
+
+pub use simple_sync::SimpleSync;
+
+/// Currently implemented sync methods.
+pub enum SyncMethod {
+    SimpleSync,
+}

beacon_node/network/src/sync/simple_sync.rs

@@ -0,0 +1,39 @@
+use crate::beacon_chain::BeaconChain;
+use libp2p::PeerId;
+use std::collections::HashMap;
+use std::sync::Arc;
+use types::{Epoch, Hash256, Slot};
+
+/// Keeps track of syncing information for known connected peers.
+pub struct PeerSyncInfo {
+    latest_finalized_root: Hash256,
+    latest_finalized_epoch: Epoch,
+    best_root: Hash256,
+    best_slot: Slot,
+}
+
+/// The current syncing state.
+pub enum SyncState {
+    Idle,
+    Downloading,
+    Stopped,
+}
+
+/// Simple Syncing protocol.
+//TODO: Decide for HELLO messages whether its better to keep current in RAM or build on the fly
+//when asked.
+pub struct SimpleSync {
+    known_peers: HashMap<PeerId, PeerSyncInfo>,
+    state: SyncState,
+    network_id: u8,
+}
+
+impl SimpleSync {
+    pub fn new(beacon_chain: Arc<BeaconChain>) -> Self {
+        SimpleSync {
+            known_peers: HashMap::new(),
+            state: SyncState::Idle,
+            network_id: beacon_chain.get_spec().network_id,
+        }
+    }
+}