From bc162637a638f80d89da7b46b05aad5f167d6a6a Mon Sep 17 00:00:00 2001
From: Carl <carl@solana.com>
Date: Mon, 11 Feb 2019 17:30:46 -0800
Subject: [PATCH] Add is_last_blob flag to blob to signal the end of a slot

---
 src/broadcast_service.rs |  8 ++++++--
 src/packet.rs            | 11 +++++++++++
 tests/multinode.rs       |  7 +++++--
 3 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/src/broadcast_service.rs b/src/broadcast_service.rs
index 2c85c05638..ef7e8c13c1 100644
--- a/src/broadcast_service.rs
+++ b/src/broadcast_service.rs
@@ -60,7 +60,7 @@ impl Broadcast {
             num_entries += entries.len();
             ventries.push(entries);
         }
-        let last_tick = {
+        let contains_last_tick = {
             if let Some(Some(last)) = ventries.last().map(|entries| entries.last()) {
                 last.tick_height == self.max_tick_height
             } else {
@@ -90,10 +90,14 @@ impl Broadcast {
 
         inc_new_counter_info!("streamer-broadcast-sent", blobs.len());
 
+        if contains_last_tick {
+            blobs.last().unwrap().write().unwrap().set_is_last_blob();
+        }
+
         blocktree.write_shared_blobs(&blobs)?;
 
         // Send out data
-        ClusterInfo::broadcast(&self.id, last_tick, &broadcast_table, sock, &blobs)?;
+        ClusterInfo::broadcast(&self.id, contains_last_tick, &broadcast_table, sock, &blobs)?;
 
         // Fill in the coding blob data from the window data blobs
         #[cfg(feature = "erasure")]
diff --git a/src/packet.rs b/src/packet.rs
index 10790dddf6..80196634b9 100644
--- a/src/packet.rs
+++ b/src/packet.rs
@@ -292,6 +292,8 @@ macro_rules! align {
 
 pub const BLOB_HEADER_SIZE: usize = align!(SIZE_RANGE.end, 8);
 
+pub const BLOB_FLAG_IS_LAST: u32 = 0x2;
+
 pub const BLOB_FLAG_IS_CODING: u32 = 0x1;
 
 impl Blob {
@@ -350,6 +352,15 @@ impl Blob {
         self.set_flags(flags | BLOB_FLAG_IS_CODING);
     }
 
+    pub fn set_is_last_blob(&mut self) {
+        let flags = self.flags();
+        self.set_flags(flags | BLOB_FLAG_IS_LAST);
+    }
+
+    pub fn is_last_blob(&self) -> bool {
+        (self.flags() & BLOB_FLAG_IS_LAST) != 0
+    }
+
     pub fn data_size(&self) -> u64 {
         LittleEndian::read_u64(&self.data[SIZE_RANGE])
     }
diff --git a/tests/multinode.rs b/tests/multinode.rs
index b27cea59dc..02528cc55a 100644
--- a/tests/multinode.rs
+++ b/tests/multinode.rs
@@ -1751,13 +1751,14 @@ fn test_fullnode_rotate(ticks_per_slot: u64, slots_per_epoch: u64) {
     let leader_pubkey = leader_keypair.pubkey().clone();
     let leader = Node::new_localhost_with_pubkey(leader_keypair.pubkey());
     let leader_info = leader.info.clone();
-    let (_mint, leader_ledger_path, _last_entry_height, _last_id, last_entry_id) =
+    let (_mint, leader_ledger_path, _tick_height, _last_entry_height, _last_id, last_entry_id) =
         create_tmp_sample_ledger(
             "fullnode_transact_while_rotating_fast",
             1_000_000_000_000_000_000,
             0,
             leader_pubkey,
             123,
+            ticks_per_slot,
         );
     info!("ledger is {}", leader_ledger_path);
 
@@ -1779,7 +1780,9 @@ fn test_fullnode_rotate(ticks_per_slot: u64, slots_per_epoch: u64) {
             fullnode_config.ledger_config(),
         )
         .unwrap();
-        blocktree.write_entries(1, 0, &entries).unwrap();
+        blocktree
+            .write_entries(1, 0, ticks_per_slot, 0, &entries)
+            .unwrap();
         tick_height_of_next_rotation += 1;
     }