Chunk blobs into window size to avoid window overrun

Fixes #447

src/streamer.rs

@@ -446,22 +446,33 @@ fn broadcast(
     while let Ok(mut nq) = r.try_recv() {
         dq.append(&mut nq);
     }
-    let mut blobs: Vec<_> = dq.into_iter().collect();
+
+    // flatten deque to vec
+    let blobs_vec: Vec<_> = dq.into_iter().collect();
+
+    // We could receive more blobs than window slots so
+    // break them up into window-sized chunks to process
+    let blobs_chunked: Vec<_> = blobs_vec
+        .chunks(WINDOW_SIZE)
+        .map(|x| x.to_vec())
+        .collect();
 
     print_window(window, *receive_index as usize);
 
+    for mut blobs in blobs_chunked {
         // Insert the coding blobs into the blob stream
         #[cfg(feature = "erasure")]
         erasure::add_coding_blobs(recycler, &mut blobs, *receive_index);
 
         let blobs_len = blobs.len();
-    info!("broadcast blobs.len: {}", blobs_len);
+        debug!("broadcast blobs.len: {}", blobs_len);
 
         // Index the blobs
         Crdt::index_blobs(crdt, &blobs, receive_index)?;
         // keep the cache of blobs that are broadcast
         {
             let mut win = window.write().unwrap();
+            assert!(blobs.len() <= win.len());
             for b in &blobs {
                 let ix = b.read().unwrap().get_index().expect("blob index");
                 let pos = (ix as usize) % WINDOW_SIZE;
@@ -489,20 +500,18 @@ fn broadcast(
         // Fill in the coding blob data from the window data blobs
         #[cfg(feature = "erasure")]
         {
-        if erasure::generate_coding(
+            erasure::generate_coding(
                 &mut window.write().unwrap(),
                 *receive_index as usize,
                 blobs_len,
-        ).is_err()
-        {
-            return Err(Error::GenericError);
-        }
+            ).map_err(|_| Error::GenericError)?;
         }
 
         *receive_index += blobs_len as u64;
 
         // Send blobs out from the window
         Crdt::broadcast(crdt, &window, &sock, transmit_index, *receive_index)?;
+    }
     Ok(())
 }