From 38ccc02eaa1665a52b41aa1f69521f3880d313fa Mon Sep 17 00:00:00 2001
From: Maciej Hirsz <1096222+maciejhirsz@users.noreply.github.com>
Date: Thu, 20 Feb 2020 14:38:58 +0100
Subject: [PATCH] Quick subscribe (#232)

* feat: Send chain head ahead of node list

* feat: Partition node list into batches of 32
---
 backend/src/chain.rs | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/backend/src/chain.rs b/backend/src/chain.rs
index 425ac5f..7cb8d92 100644
--- a/backend/src/chain.rs
+++ b/backend/src/chain.rs
@@ -392,7 +392,15 @@ impl Handler<Subscribe> for Chain {
         ));
         self.serializer.push(feed::BestFinalized(self.finalized.height, self.finalized.hash));
 
-        for (nid, node) in self.nodes.iter() {
+        for (idx, (nid, node)) in self.nodes.iter().enumerate() {
+            // Send subscribtion confirmation and chain head before doing all the nodes,
+            // and continue sending batches of 32 nodes a time over the wire subsequently
+            if idx % 32 == 0 {
+                if let Some(serialized) = self.serializer.finalize() {
+                    feed.do_send(serialized);
+                }
+            }
+
             self.serializer.push(feed::AddedNode(nid, node));
             self.serializer.push(feed::FinalizedBlock(nid, node.finalized().height, node.finalized().hash));
             if node.stale() {