Add growing buffer support to MRP

mrp/src/stream.rs

@@ -84,6 +84,21 @@ pub enum MrpSendError {
     InnerSendFailed(anyhow::Error),
 }
 
+impl<SendData, ReceiveData> Default for MrpStream<SendData, ReceiveData>
+where
+    SendData: Clone + Debug,
+    ReceiveData: Clone + Debug,
+{
+    /// allows for unlimited buffers
+    fn default() -> Self {
+        Self {
+            should_ack: false,
+            send_buffer: BufferWindow::<PendingPacket<SendData>>::new(Self::INITIAL_SEQNUM),
+            receive_buffer: BufferWindow::<ReceiveData>::new(Self::INITIAL_ACKNUM),
+        }
+    }
+}
+
 impl<SendData, ReceiveData> MrpStream<SendData, ReceiveData>
 where
     SendData: Clone + Debug,
@@ -92,14 +107,17 @@ where
     const INITIAL_SEQNUM: u64 = 1;
     const INITIAL_ACKNUM: u64 = 1;
 
-    pub fn new(max_window_size: usize) -> Self {
+    pub fn with_capacity_limit(max_window_size: usize) -> Self {
         Self {
             should_ack: false,
-            send_buffer: BufferWindow::<PendingPacket<SendData>>::new(
+            send_buffer: BufferWindow::<PendingPacket<SendData>>::with_capacity_limit(
                 max_window_size,
                 Self::INITIAL_SEQNUM,
             ),
-            receive_buffer: BufferWindow::<ReceiveData>::new(max_window_size, Self::INITIAL_ACKNUM),
+            receive_buffer: BufferWindow::<ReceiveData>::with_capacity_limit(
+                max_window_size,
+                Self::INITIAL_ACKNUM,
+            ),
         }
     }
 
@@ -126,7 +144,7 @@ where
     /// # use mrp::*;
     /// # use std::time::{Duration, Instant};
     /// type Packet = PacketWrapper<i32>;
-    /// let mut stream = MrpStream::<Packet, Packet>::new(8);
+    /// let mut stream = MrpStream::<Packet, Packet>::with_capacity_limit(8);
     /// let mut inbox = Vec::with_capacity(8);
     ///
     /// for i in 1..=9 {
@@ -195,8 +213,8 @@ where
     /// let ack = || PacketWrapper(MrpHeader::default(), "".to_string());
     /// let (to_alice, alice_inbox) : (Sender<Packet>, Receiver<Packet>) = mpsc::channel();
     /// let (to_bob, bob_inbox) : (Sender<Packet>, Receiver<Packet>) = mpsc::channel();
-    /// let mut alice = MrpStream::<Packet, Packet>::new(8);
-    /// let mut bob = MrpStream::<Packet, Packet>::new(8);
+    /// let mut alice = MrpStream::<Packet, Packet>::with_capacity_limit(8);
+    /// let mut bob = MrpStream::<Packet, Packet>::with_capacity_limit(8);
     /// let tick = Duration::from_millis(10);
     ///
     /// thread::spawn(move ||  {
@@ -290,6 +308,14 @@ where
         }
     }
 
+    pub fn send_len(&self) -> usize {
+        self.send_buffer.len()
+    }
+
+    pub fn receive_len(&self) -> usize {
+        self.receive_buffer.len()
+    }
+
     fn update_send_window(
         &mut self,
         received_ack_num: u64,
@@ -430,13 +456,13 @@ mod tests {
 
     impl TestCase {
         fn new(
-            buffer_size: usize,
+            buffer_size: Option<usize>,
             alice_schedule: PacketSchedule,
             bob_schedule: PacketSchedule,
         ) -> Self {
             TestCase {
-                alice: MrpStream::new(buffer_size),
-                bob: MrpStream::new(buffer_size),
+                alice: buffer_size.map_or_else(MrpStream::default, MrpStream::with_capacity_limit),
+                bob: buffer_size.map_or_else(MrpStream::default, MrpStream::with_capacity_limit),
                 alice_inbox: RefCell::new(vec![]),
                 bob_inbox: RefCell::new(vec![]),
                 alice_schedule,
@@ -584,12 +610,40 @@ mod tests {
     static NEVER_TIMEOUT: u64 = 10000000;
     static NO_RECEIVES: Vec<u64> = vec![];
 
+    #[test]
+    fn test_unlimited_buffers() {
+        // we send a large number at once so both send and receive buffers grow
+        let num_to_send = 512;
+        let mut tc = TestCase::new(
+            None,
+            Event::schedule_of((0..num_to_send).map(|_| (1, 5)).collect()),
+            Event::schedule_of((0..num_to_send).map(|_| (1, 5)).collect()),
+        );
+
+        tc.run_to(1);
+        assert_sent(tc.send_from_alice(NEVER_TIMEOUT), num_to_send);
+        assert_sent(tc.send_from_bob(NEVER_TIMEOUT), num_to_send);
+        assert_eq!(tc.recv_for_alice(), NO_RECEIVES);
+        assert_eq!(tc.recv_for_bob(), NO_RECEIVES);
+        assert_eq!(tc.updates_from_alice(), NO_UPDATES);
+        assert_eq!(tc.updates_from_bob(), NO_UPDATES);
+
+        let expected_recv = (1..=num_to_send as u64).collect::<Vec<_>>();
+        tc.run_to(5);
+        assert_sent(tc.send_from_alice(NEVER_TIMEOUT), 0);
+        assert_sent(tc.send_from_bob(NEVER_TIMEOUT), 0);
+        assert_eq!(tc.recv_for_alice(), expected_recv);
+        assert_eq!(tc.recv_for_bob(), expected_recv);
+        assert_eq!(tc.updates_from_alice(), acked(num_to_send as u64 + 1));
+        assert_eq!(tc.updates_from_bob(), acked(num_to_send as u64 + 1));
+    }
+
     #[test]
     fn test_ping_pong_one_direction() {
         // Every tick, Alice sends a packet, Bob receives it and acks it
         // and Alice receives the ack
         let mut tc = TestCase::new(
-            16,
+            Some(16),
             Event::schedule_of((1..50).map(|i| (i, i)).collect()),
             Event::schedule_of(vec![]),
         );
@@ -609,7 +663,7 @@ mod tests {
     fn test_ping_pong_two_directions() {
         // Both Bob and Alice send, receive, ack, and receive ack in the same tick
         let mut tc = TestCase::new(
-            16,
+            Some(16),
             Event::schedule_of((1..50).map(|i| (i, i)).collect()),
             Event::schedule_of((1..50).map(|i| (i, i)).collect()),
         );
@@ -642,7 +696,7 @@ mod tests {
             (ts, ts + delay)
         };
         let mut tc = TestCase::new(
-            16,
+            Some(16),
             Event::schedule_of((10..=60).map(event).collect()),
             Event::schedule_of((10..=60).map(event).collect()),
         );
@@ -675,7 +729,7 @@ mod tests {
         // Bob sends packets with similar pattern to
         // [test_out_of_order_buffering], receiving 9 every 10th tick
         let mut tc = TestCase::new(
-            16,
+            Some(16),
             Event::schedule_of(vec![
                 (1, 1),
                 (2, 2),
@@ -807,7 +861,7 @@ mod tests {
         // Alice sends packets with timeouts that cause retransmissions.
         // Retransmissions will instantly succeed (same tick).
         let mut tc = TestCase::new(
-            16,
+            Some(16),
             Event::schedule_of(vec![
                 // Packets 1-7: Test head of line blocking. Packet 4 is resent at t=10,
                 // so Packets 4-6 are returned at t=10 resulting in ack(7) at t=10, ack(8) at t=11
@@ -956,8 +1010,8 @@ mod tests {
         delay_min: Duration,
         delay_max: Duration,
     ) {
-        let alice = MrpStream::new(64);
-        let bob = MrpStream::new(64);
+        let alice = MrpStream::with_capacity_limit(64);
+        let bob = MrpStream::with_capacity_limit(64);
         let (to_alice, alice_inbox) = mpsc::channel();
         let (to_bob, bob_inbox) = mpsc::channel();
         let alice_receiver = DelayReceiver::new(

mrp/src/window.rs

@@ -3,6 +3,7 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 //
 
+use std::cmp::min;
 use std::collections::VecDeque;
 use std::fmt::Debug;
 use std::result::Result;
@@ -20,18 +21,31 @@ pub enum WindowError {
 pub struct BufferWindow<T: Debug> {
     left: u64,
     data: VecDeque<Option<T>>,
+    capacity_limit: usize,
 }
 
 impl<T: Debug> BufferWindow<T> {
+    const DEFAULT_SIZE: usize = 16;
+
     /// left_bounds must be greater than 0
-    pub fn new(max_size: usize, left_bounds: u64) -> Self {
+    /// capacity_limit must be greater than 0
+    pub fn with_capacity_limit(capacity_limit: usize, left_bounds: u64) -> Self {
         assert_ne!(left_bounds, 0, "Left bounds must be greater than 0");
+        assert_ne!(capacity_limit, 0, "Capacity limit must be greater than 0");
+        let initial_capacity = min(capacity_limit, Self::DEFAULT_SIZE);
+
         Self {
             left: left_bounds,
-            data: VecDeque::with_capacity(max_size),
+            data: VecDeque::with_capacity(initial_capacity),
+            capacity_limit,
         }
     }
 
+    pub fn new(left_bounds: u64) -> Self {
+        assert_ne!(left_bounds, 0, "Left bounds must be greater than 0");
+        Self::with_capacity_limit(usize::MAX, left_bounds)
+    }
+
     fn get_pos(&self, seqnum: u64) -> Result<usize, WindowError> {
         if seqnum < self.left_bounds() {
             return Err(WindowError::BeforeWindow);
@@ -43,13 +57,17 @@ impl<T: Debug> BufferWindow<T> {
         Ok((seqnum - self.left) as usize)
     }
 
-    /// Max size of the window
-    fn capacity(&self) -> usize {
-        self.data.capacity()
+    /// Max capacity of the window. Is not the current capacity
+    fn capacity_limit(&self) -> usize {
+        self.capacity_limit
+    }
+
+    pub fn len(&self) -> usize {
+        self.data.len()
     }
 
     pub fn is_full(&self) -> bool {
-        self.data.len() == self.capacity()
+        self.data.len() == self.capacity_limit()
     }
 
     /// the highest seqnum of an element in the window or previously processed
@@ -65,7 +83,7 @@ impl<T: Debug> BufferWindow<T> {
 
     /// Current highest valid seqnum
     pub fn right_bounds(&self) -> u64 {
-        self.left + (self.capacity() as u64) - 1
+        self.left.saturating_add(self.capacity_limit() as u64 - 1)
     }
 
     #[cfg(test)]
@@ -187,9 +205,9 @@ mod tests {
     fn window_basics() {
         let max_size = 4;
         let mut base = 1000;
-        let mut w = BufferWindow::new(max_size, 1);
+        let mut w = BufferWindow::with_capacity_limit(max_size, 1);
 
-        assert_eq!(w.capacity(), max_size);
+        assert_eq!(w.capacity_limit(), max_size);
 
         // initializes to correct bounds
         assert_eq!(w.left_bounds(), 1);
@@ -198,14 +216,14 @@ mod tests {
         // Past bounds checking
         assert_eq!(w.put(0, 0), Err(WindowError::BeforeWindow));
         assert_eq!(w.put(5, 0), Err(WindowError::AfterWindow));
-        assert_eq!(w.capacity(), max_size);
+        assert_eq!(w.capacity_limit(), max_size);
 
         // Fill up initial window without changing bounds
         for s in 1..=max_size as u64 {
             assert_eq!(w.put(s, base + s), Ok(()));
             assert_eq!(w.left_bounds(), 1);
             assert_eq!(w.right_bounds(), 4);
-            assert_eq!(w.capacity(), max_size);
+            assert_eq!(w.capacity_limit(), max_size);
         }
 
         assert!(w.is_full());
@@ -216,14 +234,14 @@ mod tests {
             assert_eq!(w.put(s, base + s), Ok(()));
             assert_eq!(w.left_bounds(), 1);
             assert_eq!(w.right_bounds(), 4);
-            assert_eq!(w.capacity(), max_size);
+            assert_eq!(w.capacity_limit(), max_size);
         }
 
         // drains contiguous front and updates bounds
         assert_eq!(w.drain_front(), Some((5, vec![2001, 2002, 2003, 2004])));
         assert_eq!(w.left_bounds(), 5);
         assert_eq!(w.right_bounds(), 8);
-        assert_eq!(w.capacity(), max_size);
+        assert_eq!(w.capacity_limit(), max_size);
 
         // Past bounds checking
         assert_eq!(w.put(1, 0), Err(WindowError::BeforeWindow));
@@ -235,20 +253,20 @@ mod tests {
         assert_eq!(w.put(6, 3002), Ok(()));
         assert_eq!(w.put(8, 3004), Ok(()));
         assert!(w.is_full());
-        assert_eq!(w.capacity(), max_size);
+        assert_eq!(w.capacity_limit(), max_size);
 
         // no drain, window does not move
         assert_eq!(w.drain_front(), None);
         assert_eq!(w.left_bounds(), 5);
         assert_eq!(w.right_bounds(), 8);
-        assert_eq!(w.capacity(), max_size);
+        assert_eq!(w.capacity_limit(), max_size);
 
         // partial drain, window moves
         assert_eq!(w.put(5, 3001), Ok(()));
         assert_eq!(w.drain_front(), Some((7, vec![3001, 3002])));
         assert_eq!(w.left_bounds(), 7);
         assert_eq!(w.right_bounds(), 10);
-        assert_eq!(w.capacity(), max_size);
+        assert_eq!(w.capacity_limit(), max_size);
 
         // Past bounds checking
         assert_eq!(w.put(6, 0), Err(WindowError::BeforeWindow));
@@ -261,22 +279,22 @@ mod tests {
         assert_eq!(w.drop_front(1), 8);
         assert_eq!(w.left_bounds(), 8);
         assert_eq!(w.right_bounds(), 11);
-        assert_eq!(w.capacity(), max_size);
+        assert_eq!(w.capacity_limit(), max_size);
 
         // can now drain, advance window
         assert_eq!(w.drain_front(), Some((9, vec![3004])));
         assert_eq!(w.left_bounds(), 9);
         assert_eq!(w.right_bounds(), 12);
-        assert_eq!(w.capacity(), max_size);
+        assert_eq!(w.capacity_limit(), max_size);
 
         // clear removes all data, and updates window
         assert_eq!(w.put(9, 5001), Ok(()));
         assert_eq!(w.put(10, 5002), Ok(()));
         assert_eq!(w.put(11, 5003), Ok(()));
         assert_eq!(w.put(12, 5004), Ok(()));
-        assert_eq!(w.capacity(), max_size);
+        assert_eq!(w.capacity_limit(), max_size);
         w.clear(100);
-        assert_eq!(w.capacity(), max_size);
+        assert_eq!(w.capacity_limit(), max_size);
         assert_eq!(w.left_bounds(), 100);
         assert_eq!(w.right_bounds(), 103);
         assert_eq!(w.drain_front(), None);
@@ -290,7 +308,7 @@ mod tests {
         assert_eq!(w.drop_front(9_800), 10_000);
         assert_eq!(w.left_bounds(), 10_000);
         assert_eq!(w.right_bounds(), 10_003);
-        assert_eq!(w.capacity(), max_size);
+        assert_eq!(w.capacity_limit(), max_size);
 
         // drop non-contiguous works
         assert_eq!(w.put(10_003, 4001), Ok(()));
@@ -302,7 +320,7 @@ mod tests {
 
     #[test]
     fn window_iter() {
-        let mut w: BufferWindow<u64> = BufferWindow::new(4, 1);
+        let mut w: BufferWindow<u64> = BufferWindow::with_capacity_limit(4, 1);
 
         // empty window test
         let mut iter = w.iter();
@@ -353,4 +371,28 @@ mod tests {
         assert_eq!(iter.next(), Some(Some(&2003)));
         assert_eq!(iter.next(), None);
     }
+
+    #[test]
+    fn test_growing_window() {
+        fn test_window(mut w: BufferWindow<bool>) {
+            for i in 1..(2 * w.len() as u64) {
+                assert_eq!(
+                    Ok(()),
+                    w.put(i, true),
+                    "Should grow with contiguous appends"
+                );
+            }
+
+            for i in (w.max_seen_seqnum()..(4 * w.max_seen_seqnum())).step_by(4) {
+                assert_eq!(
+                    Ok(()),
+                    w.put(i, true),
+                    "Should grow with non-contiguous appends"
+                );
+            }
+        }
+
+        test_window(BufferWindow::new(1));
+        test_window(BufferWindow::with_capacity_limit(1024, 1));
+    }
 }

src/rust/src/core/group_call.rs

@@ -1354,7 +1354,7 @@ impl Client {
                     raised_hands: Vec::new(),
                     raise_hand_state: RaiseHandState::default(),
 
-                    sfu_reliable_stream: MrpStream::new(RELIABLE_RTP_BUFFER_SIZE),
+                    sfu_reliable_stream: MrpStream::with_capacity_limit(RELIABLE_RTP_BUFFER_SIZE),
 
                     actor,
                 })