feat: add stats reporting hooks

moq-relay-ietf/Cargo.toml

@@ -64,4 +64,4 @@ tracing-subscriber = "0.3"
 thiserror = "2.0.17"
 
 # misc
-#once_cell = "1.21.3"
+once_cell = "1.21.3"

moq-relay-ietf/src/lib.rs

@@ -36,6 +36,7 @@ mod producer;
 mod relay;
 mod remote;
 mod session;
+pub mod stats;
 mod web;
 
 pub use api::*;

moq-relay-ietf/src/stats.rs

@@ -0,0 +1,212 @@
+use std::sync::Arc;
+use tokio::sync::RwLock;
+
+#[doc(hidden)]
+pub static GLOBAL_STATS_COLLECTOR: once_cell::sync::Lazy<Arc<RwLock<Box<dyn Stats>>>> =
+    once_cell::sync::Lazy::new(|| Arc::new(RwLock::new(Box::new(NoopStatsCollector::default()))));
+
+/// Set a custom stats collector implementation.
+///
+/// This should be called early in application startup, before any stats are reported.
+pub async fn set_collector(collector: Box<dyn Stats>) {
+    let mut guard = GLOBAL_STATS_COLLECTOR.write().await;
+    *guard = collector;
+}
+
+/// A simple trait for reporting relay stats.
+///
+/// Implementors decide what to do when these methods are called - whether to
+/// update Prometheus counters, send to StatsD, log, or do nothing at all.
+pub trait Stats: Send + Sync + 'static {
+    /// Called when a new session is established.
+    fn session_created(&self);
+
+    /// Called when a session is closed.
+    fn session_dropped(&self);
+
+    /// publisher, subscriber should always be same because for each
+    /// session we have one publisher and one subscriber
+    /// Called when a new publisher is added.
+    fn publisher_created(&self);
+
+    /// Called when a publisher is removed.
+    fn publisher_dropped(&self);
+
+    /// Called when a new subscriber is added.
+    fn subscriber_created(&self);
+
+    /// Called when a subscriber is removed.
+    fn subscriber_dropped(&self);
+
+    /// Called when a created namespace is announced.
+    fn namespace_created(&self);
+
+    /// Called when a namespace is removed.
+    fn namespace_dropped(&self);
+
+    /// Called when a created track is published.
+    fn track_published(&self);
+
+    /// Called when a track is removed.
+    fn track_unpublished(&self);
+
+    /// Called when a namespace is announced
+    fn namespace_announced(&self);
+
+    /// Called when a namespace is removed
+    fn namespace_unannounced(&self);
+}
+
+#[derive(Clone, Default)]
+pub struct NoopStatsCollector {}
+
+impl Stats for NoopStatsCollector {
+    fn session_created(&self) {}
+    fn session_dropped(&self) {}
+    fn publisher_created(&self) {}
+    fn publisher_dropped(&self) {}
+    fn subscriber_created(&self) {}
+    fn subscriber_dropped(&self) {}
+    fn namespace_created(&self) {}
+    fn namespace_dropped(&self) {}
+    fn track_published(&self) {}
+    fn track_unpublished(&self) {}
+    fn namespace_announced(&self) {}
+    fn namespace_unannounced(&self) {}
+}
+
+// ============================================================================
+// Macros for reporting stats via GLOBAL_STATS_COLLECTOR
+// ============================================================================
+
+/// Report that a session was created.
+#[macro_export]
+macro_rules! session_created {
+    () => {
+        $crate::stats::GLOBAL_STATS_COLLECTOR
+            .read()
+            .await
+            .session_created()
+    };
+}
+
+/// Report that a session was dropped.
+#[macro_export]
+macro_rules! session_dropped {
+    () => {
+        $crate::stats::GLOBAL_STATS_COLLECTOR
+            .read()
+            .await
+            .session_dropped()
+    };
+}
+
+/// Report that a publisher was created.
+#[macro_export]
+macro_rules! publisher_created {
+    () => {
+        $crate::stats::GLOBAL_STATS_COLLECTOR
+            .read()
+            .await
+            .publisher_created()
+    };
+}
+
+/// Report that a publisher was dropped.
+#[macro_export]
+macro_rules! publisher_dropped {
+    () => {
+        $crate::stats::GLOBAL_STATS_COLLECTOR
+            .read()
+            .await
+            .publisher_dropped()
+    };
+}
+
+/// Report that a subscriber was created.
+#[macro_export]
+macro_rules! subscriber_created {
+    () => {
+        $crate::stats::GLOBAL_STATS_COLLECTOR
+            .read()
+            .await
+            .subscriber_created()
+    };
+}
+
+/// Report that a subscriber was dropped.
+#[macro_export]
+macro_rules! subscriber_dropped {
+    () => {
+        $crate::stats::GLOBAL_STATS_COLLECTOR
+            .read()
+            .await
+            .subscriber_dropped()
+    };
+}
+
+/// Report that a namespace was created.
+#[macro_export]
+macro_rules! namespace_created {
+    () => {
+        $crate::stats::GLOBAL_STATS_COLLECTOR
+            .read()
+            .await
+            .namespace_created()
+    };
+}
+
+/// Report that a namespace was dropped.
+#[macro_export]
+macro_rules! namespace_dropped {
+    () => {
+        $crate::stats::GLOBAL_STATS_COLLECTOR
+            .read()
+            .await
+            .namespace_dropped()
+    };
+}
+
+/// Report that a track was published.
+#[macro_export]
+macro_rules! track_published {
+    () => {
+        $crate::stats::GLOBAL_STATS_COLLECTOR
+            .read()
+            .await
+            .track_published()
+    };
+}
+
+/// Report that a track was unpublished.
+#[macro_export]
+macro_rules! track_unpublished {
+    () => {
+        $crate::stats::GLOBAL_STATS_COLLECTOR
+            .read()
+            .await
+            .track_unpublished()
+    };
+}
+
+/// Report that a namespace was announced.
+#[macro_export]
+macro_rules! namespace_announced {
+    () => {
+        $crate::stats::GLOBAL_STATS_COLLECTOR
+            .read()
+            .await
+            .namespace_announced()
+    };
+}
+
+/// Report that a namespace was unannounced.
+#[macro_export]
+macro_rules! namespace_unannounced {
+    () => {
+        $crate::stats::GLOBAL_STATS_COLLECTOR
+            .read()
+            .await
+            .namespace_unannounced()
+    };
+}