Add is_last_blob flag to blob to signal the end of a slot

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")]

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])
     }