perf: specialize slice extension in Datagram::encode

quinn-proto/src/connection/mod.rs

@@ -469,7 +469,7 @@ impl Connection {
                 self.stats.udp_tx.bytes += buf.len() as u64;
                 return Some(Transmit {
                     destination,
-                    contents: buf,
+                    contents: buf.freeze(),
                     ecn: None,
                     segment_size: None,
                     src_ip: self.local_ip,
@@ -836,7 +836,7 @@ impl Connection {
 
         Some(Transmit {
             destination: self.path.remote,
-            contents: buf,
+            contents: buf.freeze(),
             ecn: if self.path.sending_ecn {
                 Some(EcnCodepoint::Ect0)
             } else {

quinn-proto/src/endpoint.rs

@@ -196,7 +196,7 @@ impl Endpoint {
                 self.transmits.push_back(Transmit {
                     destination: remote,
                     ecn: None,
-                    contents: buf,
+                    contents: buf.freeze(),
                     segment_size: None,
                     src_ip: local_ip,
                 });
@@ -359,7 +359,7 @@ impl Endpoint {
         self.transmits.push_back(Transmit {
             destination: addresses.remote,
             ecn: None,
-            contents: buf,
+            contents: buf.freeze(),
             segment_size: None,
             src_ip: addresses.local_ip,
         });
@@ -547,7 +547,7 @@ impl Endpoint {
                 self.transmits.push_back(Transmit {
                     destination: addresses.remote,
                     ecn: None,
-                    contents: buf,
+                    contents: buf.freeze(),
                     segment_size: None,
                     src_ip: addresses.local_ip,
                 });
@@ -703,7 +703,7 @@ impl Endpoint {
         self.transmits.push_back(Transmit {
             destination: addresses.remote,
             ecn: None,
-            contents: buf,
+            contents: buf.freeze(),
             segment_size: None,
             src_ip: addresses.local_ip,
         })

quinn-proto/src/frame.rs

@@ -4,7 +4,7 @@ use std::{
     ops::{Range, RangeInclusive},
 };
 
-use bytes::{Buf, BufMut, Bytes};
+use bytes::{Buf, BufMut, Bytes, BytesMut};
 use tinyvec::TinyVec;
 
 use crate::{
@@ -853,13 +853,13 @@ impl FrameStruct for Datagram {
 }
 
 impl Datagram {
-    pub(crate) fn encode<W: BufMut>(&self, length: bool, out: &mut W) {
+    pub(crate) fn encode(&self, length: bool, out: &mut BytesMut) {
         out.write(Type(*DATAGRAM_TYS.start() | u64::from(length))); // 1 byte
         if length {
             // Safe to unwrap because we check length sanity before queueing datagrams
             out.write(VarInt::from_u64(self.data.len() as u64).unwrap()); // <= 8 bytes
         }
-        out.put_slice(&self.data);
+        out.extend_from_slice(&self.data);
     }
 
     pub(crate) fn size(&self, length: bool) -> usize {

quinn-proto/src/lib.rs

@@ -38,7 +38,7 @@ mod tests;
 pub mod transport_parameters;
 mod varint;
 
-use bytes::BytesMut;
+use bytes::Bytes;
 pub use varint::{VarInt, VarIntBoundsExceeded};
 
 mod connection;
@@ -278,7 +278,7 @@ pub struct Transmit {
     /// Explicit congestion notification bits to set on the packet
     pub ecn: Option<EcnCodepoint>,
     /// Contents of the datagram
-    pub contents: BytesMut,
+    pub contents: Bytes,
     /// The segment size if this transmission contains multiple datagrams.
     /// This is `None` if the transmit only contains a single datagram
     pub segment_size: Option<usize>,

quinn-proto/src/tests/util.rs

@@ -12,6 +12,7 @@ use std::{
 };
 
 use assert_matches::assert_matches;
+use bytes::BytesMut;
 use lazy_static::lazy_static;
 use rustls::{Certificate, KeyLogFile, PrivateKey};
 use tracing::{info_span, trace};
@@ -131,9 +132,11 @@ impl Pair {
                 socket.send_to(&x.contents, x.destination).unwrap();
             }
             if self.server.addr == x.destination {
-                self.server
-                    .inbound
-                    .push_back((self.time + self.latency, x.ecn, x.contents));
+                self.server.inbound.push_back((
+                    self.time + self.latency,
+                    x.ecn,
+                    x.contents.as_ref().into(),
+                ));
             }
         }
     }
@@ -154,9 +157,11 @@ impl Pair {
                 socket.send_to(&x.contents, x.destination).unwrap();
             }
             if self.client.addr == x.destination {
-                self.client
-                    .inbound
-                    .push_back((self.time + self.latency, x.ecn, x.contents));
+                self.client.inbound.push_back((
+                    self.time + self.latency,
+                    x.ecn,
+                    x.contents.as_ref().into(),
+                ));
             }
         }
     }

quinn-udp/Cargo.toml

@@ -22,6 +22,7 @@ log = ["tracing/log"]
 maintenance = { status = "experimental" }
 
 [dependencies]
+bytes = "1"
 libc = "0.2.113"
 socket2 = "0.4" # 0.5.1 has an MSRV of 1.63
 tracing = "0.1.10"

quinn-udp/src/lib.rs

@@ -17,7 +17,7 @@ use std::{
     time::{Duration, Instant},
 };
 
-use bytes::BytesMut;
+use bytes::Bytes;
 use tracing::warn;
 
 #[cfg(unix)]
@@ -132,14 +132,14 @@ impl Default for RecvMeta {
 }
 
 /// An outgoing packet
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub struct Transmit {
     /// The socket this datagram should be sent to
     pub destination: SocketAddr,
     /// Explicit congestion notification bits to set on the packet
     pub ecn: Option<EcnCodepoint>,
     /// Contents of the datagram
-    pub contents: BytesMut,
+    pub contents: Bytes,
     /// The segment size if this transmission contains multiple datagrams.
     /// This is `None` if the transmit only contains a single datagram
     pub segment_size: Option<usize>,