quiche/recovery/gcongestion/
mod.rs

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26
27pub mod bandwidth;
28mod bbr;
29mod bbr2;
30pub mod pacer;
31mod recovery;
32
33use std::fmt::Debug;
34use std::time::Instant;
35
36use self::bandwidth::Bandwidth;
37pub use self::recovery::GRecovery;
38
39use crate::recovery::rtt::RttStats;
40use crate::recovery::rtt::INITIAL_RTT;
41
42#[derive(Debug)]
43pub struct Lost {
44    pub(super) packet_number: u64,
45    pub(super) bytes_lost: usize,
46}
47
48#[derive(Debug)]
49pub struct Acked {
50    pub(super) pkt_num: u64,
51    pub(super) time_sent: Instant,
52}
53
54#[enum_dispatch::enum_dispatch(CongestionControl)]
55#[allow(clippy::large_enum_variant)]
56#[derive(Debug)]
57pub(crate) enum Congestion {
58    BBRv2(bbr2::BBRv2),
59}
60
61impl Congestion {
62    pub(super) fn bbrv2(
63        initial_tcp_congestion_window: usize, max_congestion_window: usize,
64        max_segment_size: usize,
65    ) -> Self {
66        Congestion::BBRv2(bbr2::BBRv2::new(
67            initial_tcp_congestion_window,
68            max_congestion_window,
69            max_segment_size,
70            INITIAL_RTT,
71        ))
72    }
73}
74
75#[enum_dispatch::enum_dispatch]
76pub(super) trait CongestionControl: Debug {
77    /// Returns the size of the current congestion window in bytes. Note, this
78    /// is not the *available* window. Some send algorithms may not use a
79    /// congestion window and will return 0.
80    fn get_congestion_window(&self) -> usize;
81
82    /// Returns the size of the current congestion window in packets. Note, this
83    /// is not the *available* window. Some send algorithms may not use a
84    /// congestion window and will return 0.
85    fn get_congestion_window_in_packets(&self) -> usize;
86
87    /// Make decision on whether the sender can send right now.  Note that even
88    /// when this method returns true, the sending can be delayed due to pacing.
89    fn can_send(&self, bytes_in_flight: usize) -> bool;
90
91    /// Inform that we sent `bytes` to the wire, and if the packet is
92    /// retransmittable. `bytes_in_flight` is the number of bytes in flight
93    /// before the packet was sent. Note: this function must be called for
94    /// every packet sent to the wire.
95    fn on_packet_sent(
96        &mut self, sent_time: Instant, bytes_in_flight: usize,
97        packet_number: u64, bytes: usize, is_retransmissible: bool,
98        rtt_stats: &RttStats,
99    );
100
101    /// Inform that `packet_number` has been neutered.
102    fn on_packet_neutered(&mut self, _packet_number: u64) {}
103
104    /// Indicates an update to the congestion state, caused either by an
105    /// incoming ack or loss event timeout. `rtt_updated` indicates whether a
106    /// new `latest_rtt` sample has been taken, `prior_in_flight` the bytes in
107    /// flight prior to the congestion event. `acked_packets` and `lost_packets`
108    /// are any packets considered acked or lost as a result of the
109    /// congestion event.
110    #[allow(clippy::too_many_arguments)]
111    fn on_congestion_event(
112        &mut self, rtt_updated: bool, prior_in_flight: usize,
113        bytes_in_flight: usize, event_time: Instant, acked_packets: &[Acked],
114        lost_packets: &[Lost], least_unacked: u64, rtt_stats: &RttStats,
115    );
116
117    /// Called when an RTO fires.  Resets the retransmission alarm if there are
118    /// remaining unacked packets.
119    fn on_retransmission_timeout(&mut self, packets_retransmitted: bool);
120
121    /// Called when connection migrates and cwnd needs to be reset.
122    #[allow(dead_code)]
123    fn on_connection_migration(&mut self);
124
125    /// Adjust the current cwnd to a new maximal size
126    fn limit_cwnd(&mut self, _max_cwnd: usize) {}
127
128    fn is_in_recovery(&self) -> bool;
129
130    #[allow(dead_code)]
131    fn is_cwnd_limited(&self, bytes_in_flight: usize) -> bool;
132
133    #[cfg(test)]
134    fn is_app_limited(&self, bytes_in_flight: usize) -> bool {
135        !self.is_cwnd_limited(bytes_in_flight)
136    }
137
138    fn pacing_rate(
139        &self, bytes_in_flight: usize, rtt_stats: &RttStats,
140    ) -> Bandwidth;
141
142    fn bandwidth_estimate(&self, rtt_stats: &RttStats) -> Bandwidth;
143
144    fn update_mss(&mut self, new_mss: usize);
145
146    fn on_app_limited(&mut self, _bytes_in_flight: usize) {}
147
148    #[cfg(feature = "qlog")]
149    fn ssthresh(&self) -> Option<u64> {
150        None
151    }
152}
quiche/recovery/gcongestion/mod.rs

quiche/recovery/gcongestion/
mod.rs
