feat(metrics): add per-IP and HTTP-request metrics, propagate source IP through proxy paths, and expose new metrics to the TS adapter

rust/crates/rustproxy-passthrough/src/forwarder.rs

@@ -7,6 +7,14 @@ use tracing::debug;
 
 use rustproxy_metrics::MetricsCollector;
 
+/// Context for forwarding metrics, replacing the growing tuple pattern.
+#[derive(Clone)]
+pub struct ForwardMetricsCtx {
+    pub collector: Arc<MetricsCollector>,
+    pub route_id: Option<String>,
+    pub source_ip: Option<String>,
+}
+
 /// Perform bidirectional TCP forwarding between client and backend.
 ///
 /// This is the core data path for passthrough connections.
@@ -73,13 +81,13 @@ pub async fn forward_bidirectional_with_timeouts(
     inactivity_timeout: std::time::Duration,
     max_lifetime: std::time::Duration,
     cancel: CancellationToken,
-    metrics: Option<(Arc<MetricsCollector>, Option<String>)>,
+    metrics: Option<ForwardMetricsCtx>,
 ) -> std::io::Result<(u64, u64)> {
     // Send initial data (peeked bytes) to backend
     if let Some(data) = initial_data {
         backend.write_all(data).await?;
-        if let Some((ref m, ref rid)) = metrics {
-            m.record_bytes(data.len() as u64, 0, rid.as_deref());
+        if let Some(ref ctx) = metrics {
+            ctx.collector.record_bytes(data.len() as u64, 0, ctx.route_id.as_deref(), ctx.source_ip.as_deref());
         }
     }
 
@@ -105,8 +113,8 @@ pub async fn forward_bidirectional_with_timeouts(
             }
             total += n as u64;
             la1.store(start.elapsed().as_millis() as u64, Ordering::Relaxed);
-            if let Some((ref m, ref rid)) = metrics_c2b {
-                m.record_bytes(n as u64, 0, rid.as_deref());
+            if let Some(ref ctx) = metrics_c2b {
+                ctx.collector.record_bytes(n as u64, 0, ctx.route_id.as_deref(), ctx.source_ip.as_deref());
             }
         }
         let _ = backend_write.shutdown().await;
@@ -128,8 +136,8 @@ pub async fn forward_bidirectional_with_timeouts(
             }
             total += n as u64;
             la2.store(start.elapsed().as_millis() as u64, Ordering::Relaxed);
-            if let Some((ref m, ref rid)) = metrics_b2c {
-                m.record_bytes(0, n as u64, rid.as_deref());
+            if let Some(ref ctx) = metrics_b2c {
+                ctx.collector.record_bytes(0, n as u64, ctx.route_id.as_deref(), ctx.source_ip.as_deref());
             }
         }
         let _ = client_write.shutdown().await;
@@ -182,4 +190,3 @@ pub async fn forward_bidirectional_with_timeouts(
     watchdog.abort();
     Ok((bytes_in, bytes_out))
 }
-