From 3399b02393d097f39f2b286e15031c2498d0aac9 Mon Sep 17 00:00:00 2001
From: Paul Hauner <paul@paulhauner.com>
Date: Sun, 9 Sep 2018 18:28:36 +0200
Subject: [PATCH] Expand sync works

---
 lighthouse/sync/mod.rs           |  1 +
 lighthouse/sync/network.rs       | 44 ++++++++++++++++++++++++--------
 lighthouse/sync/sync_future.rs   | 14 ++++------
 lighthouse/sync/wire_protocol.rs | 24 +++++++++++++++++
 4 files changed, 63 insertions(+), 20 deletions(-)
 create mode 100644 lighthouse/sync/wire_protocol.rs

diff --git a/lighthouse/sync/mod.rs b/lighthouse/sync/mod.rs
index efff37624..3d7d2d8d2 100644
--- a/lighthouse/sync/mod.rs
+++ b/lighthouse/sync/mod.rs
@@ -6,6 +6,7 @@ extern crate network_libp2p;
 pub mod messages;
 pub mod network;
 pub mod sync_future;
+pub mod wire_protocol;
 
 pub use self::sync_future::run_sync_future;
 
diff --git a/lighthouse/sync/network.rs b/lighthouse/sync/network.rs
index 4954edc1c..c2d1f1149 100644
--- a/lighthouse/sync/network.rs
+++ b/lighthouse/sync/network.rs
@@ -8,10 +8,16 @@ use super::network_libp2p::message::{
     NetworkEventType,
 };
 
+use super::wire_protocol::{ WireMessageType, message_type };
+
 use super::futures::sync::mpsc::{
     UnboundedSender,
 };
 
+/// Accept a network event and perform all required processing.
+///
+/// This function should be called whenever an underlying network
+/// (e.g., libp2p) has an event to push up to the sync process.
 pub fn handle_network_event(
     event: NetworkEvent,
     db: Arc<RwLock<DB>>,
@@ -19,26 +25,42 @@ pub fn handle_network_event(
     log: Logger)
     -> Result<(), ()>
 {
+        debug!(&log, "";
+               "network_event" => format!("{:?}", &event));
         match event.event {
             NetworkEventType::PeerConnect => Ok(()),
             NetworkEventType::PeerDrop => Ok(()),
-            NetworkEventType::Message => handle_network_message(
-                event.data,
-                db,
-                network_tx,
-                log
-            )
+            NetworkEventType::Message => {
+                if let Some(data) = event.data {
+                    handle_network_message(
+                        data,
+                        db,
+                        network_tx,
+                        log)
+                } else {
+                    Ok(())
+                }
+            }
         }
 }
 
+/// Accept a message from the network and perform all required
+/// processing.
+///
+/// This function should be called whenever a peer from a network
+/// (e.g., libp2p) has sent a message to us.
 fn handle_network_message(
-    message: Option<Vec<u8>>,
+    message: Vec<u8>,
     _db: Arc<RwLock<DB>>,
     _network_tx: UnboundedSender<OutgoingMessage>,
-    log: Logger)
+    _log: Logger)
     -> Result<(), ()>
 {
-    debug!(&log, "";
-           "network_msg" => format!("{:?}", message));
-    Ok(())
+    match message_type(&message) {
+        Some(WireMessageType::Blocks) => {
+            // Do something with inbound blocks.
+            Ok(())
+        }
+        _ => Ok(())
+    }
 }
diff --git a/lighthouse/sync/sync_future.rs b/lighthouse/sync/sync_future.rs
index 05f22a878..c3b2355fb 100644
--- a/lighthouse/sync/sync_future.rs
+++ b/lighthouse/sync/sync_future.rs
@@ -21,17 +21,17 @@ type SyncReceiver = UnboundedReceiver<Vec<u8>>;
 
 /// Start a syncing tokio future.
 ///
-/// This is effectively a stub function being
-/// used to test network functionality.
-///
-/// Expect a full re-write.
+/// Uses green-threading to process messages
+/// from the network and the RPC and update
+/// the state.
 pub fn run_sync_future(
     db: Arc<RwLock<DB>>,
     network_tx: NetworkSender,
     network_rx: NetworkReceiver,
     _sync_tx: SyncSender,
     _sync_rx: SyncReceiver,
-    log: Logger) {
+    log: Logger)
+{
     let network_future = {
         network_rx
             .for_each(move |event| {
@@ -44,9 +44,5 @@ pub fn run_sync_future(
             .map_err(|_| panic!("rx failed"))
     };
 
-    /*
-     * This is an unfinished stub function.
-     */
-
     tokio::run(network_future);
 }
diff --git a/lighthouse/sync/wire_protocol.rs b/lighthouse/sync/wire_protocol.rs
new file mode 100644
index 000000000..5d4f77204
--- /dev/null
+++ b/lighthouse/sync/wire_protocol.rs
@@ -0,0 +1,24 @@
+pub enum WireMessageType {
+    Status,
+    NewBlockHashes,
+    GetBlockHashes,
+    BlockHashes,
+    GetBlocks,
+    Blocks,
+    NewBlock,
+}
+
+
+/// Determines the message type of some given
+/// message.
+///
+/// Does not check the validity of the message data,
+/// it just reads the first byte.
+pub fn message_type(message: &Vec<u8>)
+    -> Option<WireMessageType>
+{
+    match message.get(0) {
+        Some(0x06) => Some(WireMessageType::Blocks),
+        _ => None
+    }
+}