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-metrics/src/throughput.rs

@@ -1,8 +1,10 @@
+use serde::{Deserialize, Serialize};
 use std::sync::atomic::{AtomicU64, Ordering};
 use std::time::{Instant, SystemTime, UNIX_EPOCH};
 
 /// A single throughput sample.
-#[derive(Debug, Clone, Copy)]
+#[derive(Debug, Clone, Copy, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
 pub struct ThroughputSample {
     pub timestamp_ms: u64,
     pub bytes_in: u64,
@@ -106,6 +108,27 @@ impl ThroughputTracker {
         self.throughput(10)
     }
 
+    /// Return the last N samples in chronological order (oldest first).
+    pub fn history(&self, window_seconds: usize) -> Vec<ThroughputSample> {
+        let window = window_seconds.min(self.count);
+        if window == 0 {
+            return Vec::new();
+        }
+        let mut result = Vec::with_capacity(window);
+        for i in 0..window {
+            let idx = if self.write_index >= i + 1 {
+                self.write_index - i - 1
+            } else {
+                self.capacity - (i + 1 - self.write_index)
+            };
+            if idx < self.samples.len() {
+                result.push(self.samples[idx]);
+            }
+        }
+        result.reverse(); // Return oldest-first (chronological)
+        result
+    }
+
     /// How long this tracker has been alive.
     pub fn uptime(&self) -> std::time::Duration {
         self.created_at.elapsed()
@@ -170,4 +193,40 @@ mod tests {
         std::thread::sleep(std::time::Duration::from_millis(10));
         assert!(tracker.uptime().as_millis() >= 10);
     }
+
+    #[test]
+    fn test_history_returns_chronological() {
+        let mut tracker = ThroughputTracker::new(60);
+        for i in 1..=5 {
+            tracker.record_bytes(i * 100, i * 200);
+            tracker.sample();
+        }
+        let history = tracker.history(5);
+        assert_eq!(history.len(), 5);
+        // First sample should have 100 bytes_in, last should have 500
+        assert_eq!(history[0].bytes_in, 100);
+        assert_eq!(history[4].bytes_in, 500);
+    }
+
+    #[test]
+    fn test_history_wraps_around() {
+        let mut tracker = ThroughputTracker::new(3); // Small capacity
+        for i in 1..=5 {
+            tracker.record_bytes(i * 100, i * 200);
+            tracker.sample();
+        }
+        // Only last 3 should be retained
+        let history = tracker.history(10); // Ask for more than available
+        assert_eq!(history.len(), 3);
+        assert_eq!(history[0].bytes_in, 300);
+        assert_eq!(history[1].bytes_in, 400);
+        assert_eq!(history[2].bytes_in, 500);
+    }
+
+    #[test]
+    fn test_history_empty() {
+        let tracker = ThroughputTracker::new(60);
+        let history = tracker.history(10);
+        assert!(history.is_empty());
+    }
 }