fix(rustproxy-http,rustproxy-metrics): fix domain-scoped request host detection and harden connection metrics cleanup

rust/crates/rustproxy-http/src/connection_pool.rs

@@ -3,8 +3,8 @@
 //! Reuses idle keep-alive connections to avoid per-request TCP+TLS handshakes.
 //! HTTP/2 and HTTP/3 connections are multiplexed (clone the sender / share the connection).
 
-use std::sync::Arc;
 use std::sync::atomic::{AtomicU64, Ordering};
+use std::sync::Arc;
 use std::time::{Duration, Instant};
 
 use bytes::Bytes;
@@ -105,13 +105,19 @@ impl ConnectionPool {
 
     /// Try to check out an idle HTTP/1.1 sender for the given key.
     /// Returns `None` if no usable idle connection exists.
-    pub fn checkout_h1(&self, key: &PoolKey) -> Option<http1::SendRequest<BoxBody<Bytes, hyper::Error>>> {
+    pub fn checkout_h1(
+        &self,
+        key: &PoolKey,
+    ) -> Option<http1::SendRequest<BoxBody<Bytes, hyper::Error>>> {
         let mut entry = self.h1_pool.get_mut(key)?;
         let idles = entry.value_mut();
 
         while let Some(idle) = idles.pop() {
             // Check if the connection is still alive and ready
-            if idle.idle_since.elapsed() < IDLE_TIMEOUT && idle.sender.is_ready() && !idle.sender.is_closed() {
+            if idle.idle_since.elapsed() < IDLE_TIMEOUT
+                && idle.sender.is_ready()
+                && !idle.sender.is_closed()
+            {
                 // H1 pool hit — no logging on hot path
                 return Some(idle.sender);
             }
@@ -128,7 +134,11 @@ impl ConnectionPool {
 
     /// Return an HTTP/1.1 sender to the pool after the response body has been prepared.
     /// The caller should NOT call this if the sender is closed or not ready.
-    pub fn checkin_h1(&self, key: PoolKey, sender: http1::SendRequest<BoxBody<Bytes, hyper::Error>>) {
+    pub fn checkin_h1(
+        &self,
+        key: PoolKey,
+        sender: http1::SendRequest<BoxBody<Bytes, hyper::Error>>,
+    ) {
         if sender.is_closed() || !sender.is_ready() {
             return; // Don't pool broken connections
         }
@@ -145,7 +155,10 @@ impl ConnectionPool {
 
     /// Try to get a cloned HTTP/2 sender for the given key.
     /// HTTP/2 senders are Clone-able (multiplexed), so we clone rather than remove.
-    pub fn checkout_h2(&self, key: &PoolKey) -> Option<(http2::SendRequest<BoxBody<Bytes, hyper::Error>>, Duration)> {
+    pub fn checkout_h2(
+        &self,
+        key: &PoolKey,
+    ) -> Option<(http2::SendRequest<BoxBody<Bytes, hyper::Error>>, Duration)> {
         let entry = self.h2_pool.get(key)?;
         let pooled = entry.value();
         let age = pooled.created_at.elapsed();
@@ -184,16 +197,23 @@ impl ConnectionPool {
     /// Register an HTTP/2 sender in the pool. Returns the generation ID for this entry.
     /// The caller should pass this generation to the connection driver so it can use
     /// `remove_h2_if_generation` instead of `remove_h2` to avoid phantom eviction.
-    pub fn register_h2(&self, key: PoolKey, sender: http2::SendRequest<BoxBody<Bytes, hyper::Error>>) -> u64 {
+    pub fn register_h2(
+        &self,
+        key: PoolKey,
+        sender: http2::SendRequest<BoxBody<Bytes, hyper::Error>>,
+    ) -> u64 {
         let gen = self.h2_generation.fetch_add(1, Ordering::Relaxed);
         if sender.is_closed() {
             return gen;
         }
-        self.h2_pool.insert(key, PooledH2 {
-            sender,
-            created_at: Instant::now(),
-            generation: gen,
-        });
+        self.h2_pool.insert(
+            key,
+            PooledH2 {
+                sender,
+                created_at: Instant::now(),
+                generation: gen,
+            },
+        );
         gen
     }
 
@@ -204,7 +224,11 @@ impl ConnectionPool {
     pub fn checkout_h3(
         &self,
         key: &PoolKey,
-    ) -> Option<(h3::client::SendRequest<h3_quinn::OpenStreams, Bytes>, quinn::Connection, Duration)> {
+    ) -> Option<(
+        h3::client::SendRequest<h3_quinn::OpenStreams, Bytes>,
+        quinn::Connection,
+        Duration,
+    )> {
         let entry = self.h3_pool.get(key)?;
         let pooled = entry.value();
         let age = pooled.created_at.elapsed();
@@ -234,12 +258,15 @@ impl ConnectionPool {
         send_request: h3::client::SendRequest<h3_quinn::OpenStreams, Bytes>,
     ) -> u64 {
         let gen = self.h2_generation.fetch_add(1, Ordering::Relaxed);
-        self.h3_pool.insert(key, PooledH3 {
-            send_request,
-            connection,
-            created_at: Instant::now(),
-            generation: gen,
-        });
+        self.h3_pool.insert(
+            key,
+            PooledH3 {
+                send_request,
+                connection,
+                created_at: Instant::now(),
+                generation: gen,
+            },
+        );
         gen
     }
 
@@ -280,7 +307,9 @@ impl ConnectionPool {
             // Evict dead or aged-out H2 connections
             let mut dead_h2 = Vec::new();
             for entry in h2_pool.iter() {
-                if entry.value().sender.is_closed() || entry.value().created_at.elapsed() >= MAX_H2_AGE {
+                if entry.value().sender.is_closed()
+                    || entry.value().created_at.elapsed() >= MAX_H2_AGE
+                {
                     dead_h2.push(entry.key().clone());
                 }
             }