Switched mid and rid to SmolStr

webrtc/Cargo.toml

@@ -40,6 +40,7 @@ bytes = "1"
 thiserror = "1.0"
 waitgroup = "0.1.2"
 regex = "1.7.1"
+smol_str = "0.2.0"
 url = "2.2"
 rustls = { version = "0.19.0", features = ["dangerous_configuration"]}
 rcgen = { version = "0.10.0", features = ["pem", "x509-parser"]}

webrtc/src/lib.rs

@@ -12,6 +12,8 @@ pub use rtcp;
 pub use rtp;
 pub use sctp;
 pub use sdp;
+use serde::{Deserialize, Serialize};
+use smol_str::SmolStr;
 pub use srtp;
 pub use stun;
 pub use turn;
@@ -43,3 +45,25 @@ pub(crate) const SDP_ATTRIBUTE_RID: &str = "rid";
 pub(crate) const GENERATED_CERTIFICATE_ORIGIN: &str = "WebRTC";
 pub(crate) const SDES_REPAIR_RTP_STREAM_ID_URI: &str =
     "urn:ietf:params:rtp-hdrext:sdes:repaired-rtp-stream-id";
+
+#[derive(Clone, Debug, Default, PartialEq)]
+pub struct SmallStr(SmolStr);
+
+impl Serialize for SmallStr {
+    fn serialize<S>(&self, serializer: S) -> std::result::Result<S::Ok, S::Error>
+    where
+        S: serde::Serializer,
+    {
+        serializer.serialize_str(self.0.as_str())
+    }
+}
+
+impl<'de> Deserialize<'de> for SmallStr {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: serde::Deserializer<'de>,
+    {
+        let s = String::deserialize(deserializer)?;
+        Ok(SmallStr(SmolStr::new(s)))
+    }
+}

webrtc/src/peer_connection/mod.rs

@@ -66,6 +66,7 @@ use crate::sctp_transport::RTCSctpTransport;
 use crate::stats::StatsReport;
 use crate::track::track_local::TrackLocal;
 use crate::track::track_remote::TrackRemote;
+use crate::SmallStr;
 
 use ::ice::candidate::candidate_base::unmarshal_candidate;
 use ::ice::candidate::Candidate;
@@ -77,6 +78,7 @@ use interceptor::{stats, Attributes, Interceptor, RTCPWriter};
 use peer_connection_internal::*;
 use rand::{thread_rng, Rng};
 use rcgen::KeyPair;
+use smol_str::SmolStr;
 use srtp::stream::Stream;
 use std::future::Future;
 use std::pin::Pin;
@@ -454,7 +456,9 @@ impl RTCPeerConnection {
                 // 	return true
                 // }
                 let mid = t.mid();
-                let m = mid.as_ref().and_then(|mid| get_by_mid(mid, local_desc));
+                let m = mid
+                    .as_ref()
+                    .and_then(|mid| get_by_mid(mid.0.as_str(), local_desc));
                 // Step 5.2
                 if !t.stopped.load(Ordering::SeqCst) {
                     if m.is_none() {
@@ -493,8 +497,9 @@ impl RTCPeerConnection {
                             RTCSdpType::Offer => {
                                 // Step 5.3.2
                                 if let Some(remote_desc) = &current_remote_description {
-                                    if let Some(rm) =
-                                        t.mid().and_then(|mid| get_by_mid(&mid, remote_desc))
+                                    if let Some(rm) = t
+                                        .mid()
+                                        .and_then(|mid| get_by_mid(mid.0.as_str(), remote_desc))
                                     {
                                         if get_peer_direction(m) != t.direction()
                                             && get_peer_direction(rm) != t.direction().reverse()
@@ -511,18 +516,20 @@ impl RTCPeerConnection {
                                     Some(d) => d,
                                     None => return true,
                                 };
-                                let offered_direction =
-                                    match t.mid().and_then(|mid| get_by_mid(&mid, remote_desc)) {
-                                        Some(d) => {
-                                            let dir = get_peer_direction(d);
-                                            if dir == RTCRtpTransceiverDirection::Unspecified {
-                                                RTCRtpTransceiverDirection::Inactive
-                                            } else {
-                                                dir
-                                            }
+                                let offered_direction = match t
+                                    .mid()
+                                    .and_then(|mid| get_by_mid(mid.0.as_str(), remote_desc))
+                                {
+                                    Some(d) => {
+                                        let dir = get_peer_direction(d);
+                                        if dir == RTCRtpTransceiverDirection::Unspecified {
+                                            RTCRtpTransceiverDirection::Inactive
+                                        } else {
+                                            dir
                                         }
-                                        None => RTCRtpTransceiverDirection::Inactive,
-                                    };
+                                    }
+                                    None => RTCRtpTransceiverDirection::Inactive,
+                                };
 
                                 let current_direction = get_peer_direction(m);
                                 // Step 5.3.3
@@ -544,8 +551,8 @@ impl RTCPeerConnection {
                     };
 
                     if let Some(remote_desc) = &*params.current_remote_description.lock().await {
-                        return get_by_mid(&search_mid, local_desc).is_some()
-                            || get_by_mid(&search_mid, remote_desc).is_some();
+                        return get_by_mid(search_mid.0.as_str(), local_desc).is_some()
+                            || get_by_mid(search_mid.0.as_str(), remote_desc).is_some();
                     }
                 }
             }
@@ -795,10 +802,13 @@ impl RTCPeerConnection {
                         }
                     }
 
-                    t.set_mid(mid)?;
+                    t.set_mid(crate::SmallStr(SmolStr::from(mid)))?;
                 } else {
                     let greater_mid = self.internal.greater_mid.fetch_add(1, Ordering::SeqCst);
-                    t.set_mid(format!("{}", greater_mid + 1))?;
+                    t.set_mid(crate::SmallStr(SmolStr::from(format!(
+                        "{}",
+                        greater_mid + 1
+                    ))))?;
                 }
             }
 
@@ -1358,7 +1368,7 @@ impl RTCPeerConnection {
 
                         if let Some(t) = t {
                             if t.mid().is_none() {
-                                t.set_mid(mid_value.to_owned())?;
+                                t.set_mid(crate::SmallStr(SmolStr::from(mid_value)))?;
                             }
                         } else {
                             let local_direction =
@@ -1404,7 +1414,7 @@ impl RTCPeerConnection {
                             self.internal.add_rtp_transceiver(Arc::clone(&t)).await;
 
                             if t.mid().is_none() {
-                                t.set_mid(mid_value.to_owned())?;
+                                t.set_mid(SmallStr(SmolStr::from(mid_value)))?;
                             }
                         }
                     }

webrtc/src/peer_connection/peer_connection_internal.rs

@@ -1,4 +1,5 @@
 use bytes::Bytes;
+use smol_str::SmolStr;
 use tokio::time::Instant;
 
 use super::*;
@@ -9,7 +10,7 @@ use crate::stats::{
     StatsReportType,
 };
 use crate::track::TrackStream;
-use crate::{SDES_REPAIR_RTP_STREAM_ID_URI, SDP_ATTRIBUTE_RID};
+use crate::{SmallStr, SDES_REPAIR_RTP_STREAM_ID_URI, SDP_ATTRIBUTE_RID};
 use arc_swap::ArcSwapOption;
 use std::collections::VecDeque;
 use std::sync::atomic::AtomicIsize;
@@ -177,7 +178,7 @@ impl PeerConnectionInternal {
                 for t in tracks {
                     if !t.rid().is_empty() {
                         if let Some(details) =
-                            track_details_for_rid(&track_details, t.rid().to_owned())
+                            track_details_for_rid(&track_details, SmallStr(SmolStr::from(t.rid())))
                         {
                             t.set_id(details.id.clone());
                             t.set_stream_id(details.stream_id.clone());
@@ -668,7 +669,7 @@ impl PeerConnectionInternal {
             // TODO: This is dubious because of rollbacks.
             t.sender().set_negotiated();
             media_sections.push(MediaSection {
-                id: t.mid().unwrap(),
+                id: t.mid().unwrap().0.to_string(),
                 transceivers: vec![Arc::clone(t)],
                 ..Default::default()
             });
@@ -782,7 +783,7 @@ impl PeerConnectionInternal {
             for t in &local_transceivers {
                 t.sender().set_negotiated();
                 media_sections.push(MediaSection {
-                    id: t.mid().unwrap(),
+                    id: t.mid().unwrap().0.to_string(),
                     transceivers: vec![Arc::clone(t)],
                     ..Default::default()
                 });
@@ -1000,7 +1001,7 @@ impl PeerConnectionInternal {
 
             let transceivers = self.rtp_transceivers.lock().await;
             for t in &*transceivers {
-                if t.mid().as_ref() != Some(&mid) {
+                if t.mid().as_ref() != Some(&SmallStr(SmolStr::from(&mid))) {
                     continue;
                 }
 
@@ -1024,7 +1025,7 @@ impl PeerConnectionInternal {
 
                 let track = receiver
                     .receive_for_rid(
-                        rid,
+                        SmallStr(SmolStr::from(rid)),
                         params,
                         TrackStream {
                             stream_info: Some(stream_info.clone()),
@@ -1163,7 +1164,7 @@ impl PeerConnectionInternal {
     pub(super) async fn has_local_description_changed(&self, desc: &RTCSessionDescription) -> bool {
         let rtp_transceivers = self.rtp_transceivers.lock().await;
         for t in &*rtp_transceivers {
-            let m = match t.mid().and_then(|mid| get_by_mid(&mid, desc)) {
+            let m = match t.mid().and_then(|mid| get_by_mid(mid.0.as_str(), desc)) {
                 Some(m) => m,
                 None => return true,
             };
@@ -1200,7 +1201,7 @@ impl PeerConnectionInternal {
         // TODO: There's a lot of await points here that could run concurrently with `futures::join_all`.
         struct TrackInfo {
             ssrc: SSRC,
-            mid: String,
+            mid: SmallStr,
             track_id: String,
             kind: &'static str,
         }
@@ -1325,8 +1326,8 @@ impl PeerConnectionInternal {
         struct TrackInfo {
             track_id: String,
             ssrc: SSRC,
-            mid: String,
-            rid: Option<String>,
+            mid: SmallStr,
+            rid: Option<SmallStr>,
             kind: &'static str,
         }
         let mut track_infos = vec![];
@@ -1353,7 +1354,7 @@ impl PeerConnectionInternal {
             track_infos.push(TrackInfo {
                 track_id,
                 ssrc: sender.ssrc,
-                mid: mid.clone(),
+                mid,
                 rid: None,
                 kind,
             });

webrtc/src/peer_connection/sdp/mod.rs

@@ -19,14 +19,15 @@ pub mod sdp_type;
 pub mod session_description;
 
 use crate::peer_connection::MEDIA_SECTION_APPLICATION;
-use crate::SDP_ATTRIBUTE_RID;
+use crate::{SmallStr, SDP_ATTRIBUTE_RID};
 use ice::candidate::candidate_base::unmarshal_candidate;
 use ice::candidate::Candidate;
 use sdp::description::common::{Address, ConnectionInformation};
 use sdp::description::media::{MediaDescription, MediaName, RangedPort};
 use sdp::description::session::*;
 use sdp::extmap::ExtMap;
 use sdp::util::ConnectionRole;
+use smol_str::SmolStr;
 use std::collections::HashMap;
 use std::convert::From;
 use std::io::BufReader;
@@ -37,13 +38,13 @@ use url::Url;
 /// This isn't keyed by SSRC because it also needs to support rid based sources
 #[derive(Default, Debug, Clone)]
 pub(crate) struct TrackDetails {
-    pub(crate) mid: String,
+    pub(crate) mid: SmallStr,
     pub(crate) kind: RTPCodecType,
     pub(crate) stream_id: String,
     pub(crate) id: String,
     pub(crate) ssrcs: Vec<SSRC>,
     pub(crate) repair_ssrc: SSRC,
-    pub(crate) rids: Vec<String>,
+    pub(crate) rids: Vec<SmallStr>,
 }
 
 pub(crate) fn track_details_for_ssrc(
@@ -55,7 +56,7 @@ pub(crate) fn track_details_for_ssrc(
 
 pub(crate) fn track_details_for_rid(
     track_details: &[TrackDetails],
-    rid: String,
+    rid: SmallStr,
 ) -> Option<&TrackDetails> {
     track_details.iter().find(|x| x.rids.contains(&rid))
 }
@@ -185,15 +186,16 @@ pub(crate) fn track_details_from_sdp(
                         }
 
                         if track_idx < tracks_in_media_section.len() {
-                            tracks_in_media_section[track_idx].mid = mid_value.to_owned();
+                            tracks_in_media_section[track_idx].mid =
+                                SmallStr(SmolStr::from(mid_value));
                             tracks_in_media_section[track_idx].kind = codec_type;
                             tracks_in_media_section[track_idx].stream_id = stream_id.to_owned();
                             tracks_in_media_section[track_idx].id = track_id.to_owned();
                             tracks_in_media_section[track_idx].ssrcs = vec![ssrc];
                             tracks_in_media_section[track_idx].repair_ssrc = repair_ssrc;
                         } else {
                             let track_details = TrackDetails {
-                                mid: mid_value.to_owned(),
+                                mid: SmallStr(SmolStr::from(mid_value)),
                                 kind: codec_type,
                                 stream_id: stream_id.to_owned(),
                                 id: track_id.to_owned(),
@@ -212,15 +214,15 @@ pub(crate) fn track_details_from_sdp(
         let rids = get_rids(media);
         if !rids.is_empty() && !track_id.is_empty() && !stream_id.is_empty() {
             let mut simulcast_track = TrackDetails {
-                mid: mid_value.to_owned(),
+                mid: SmallStr(SmolStr::from(mid_value)),
                 kind: codec_type,
                 stream_id: stream_id.to_owned(),
                 id: track_id.to_owned(),
                 rids: vec![],
                 ..Default::default()
             };
             for rid in rids.keys() {
-                simulcast_track.rids.push(rid.to_owned());
+                simulcast_track.rids.push(SmallStr(SmolStr::from(rid)));
             }
             if simulcast_track.rids.len() == tracks_in_media_section.len() {
                 for track in &tracks_in_media_section {

webrtc/src/rtp_transceiver/mod.rs

@@ -13,7 +13,9 @@ use interceptor::{
     stream_info::{RTPHeaderExtension, StreamInfo},
     Attributes,
 };
+use smol_str::SmolStr;
 
+use crate::SmallStr;
 use log::trace;
 use serde::{Deserialize, Serialize};
 use std::fmt;
@@ -95,7 +97,7 @@ pub struct RTCRtpRtxParameters {
 /// <http://draft.ortc.org/#dom-rtcrtpcodingparameters>
 #[derive(Default, Debug, Clone, Serialize, Deserialize)]
 pub struct RTCRtpCodingParameters {
-    pub rid: String,
+    pub rid: SmallStr,
     pub ssrc: SSRC,
     pub payload_type: PayloadType,
     pub rtx: RTCRtpRtxParameters,
@@ -174,7 +176,7 @@ pub type TriggerNegotiationNeededFnOption =
 
 /// RTPTransceiver represents a combination of an RTPSender and an RTPReceiver that share a common mid.
 pub struct RTCRtpTransceiver {
-    mid: OnceCell<String>,                    //atomic.Value
+    mid: OnceCell<SmallStr>,                  //atomic.Value
     sender: SyncMutex<Arc<RTCRtpSender>>,     //atomic.Value
     receiver: SyncMutex<Arc<RTCRtpReceiver>>, //atomic.Value
 
@@ -293,14 +295,14 @@ impl RTCRtpTransceiver {
     }
 
     /// set_mid sets the RTPTransceiver's mid. If it was already set, will return an error.
-    pub(crate) fn set_mid(&self, mid: String) -> Result<()> {
+    pub(crate) fn set_mid(&self, mid: SmallStr) -> Result<()> {
         self.mid
             .set(mid)
             .map_err(|_| Error::ErrRTPTransceiverCannotChangeMid)
     }
 
     /// mid gets the Transceiver's mid value. When not already set, this value will be set in CreateOffer or create_answer.
-    pub fn mid(&self) -> Option<String> {
+    pub fn mid(&self) -> Option<SmallStr> {
         self.mid.get().map(Clone::clone)
     }
 
@@ -479,7 +481,7 @@ pub(crate) async fn find_by_mid(
     local_transceivers: &mut Vec<Arc<RTCRtpTransceiver>>,
 ) -> Option<Arc<RTCRtpTransceiver>> {
     for (i, t) in local_transceivers.iter().enumerate() {
-        if t.mid().as_deref() == Some(mid) {
+        if t.mid() == Some(SmallStr(SmolStr::from(mid))) {
             return Some(local_transceivers.remove(i));
         }
     }