chore: initialize autoresearch baseline

crates/metrics/src/counters.rs

@@ -0,0 +1,46 @@
+use std::sync::atomic::{AtomicU64, Ordering};
+use std::sync::Arc;
+
+/// Global atomic performance counters.
+#[derive(Debug, Default)]
+pub struct PerfCounters {
+    pub tokens_generated: AtomicU64,
+    pub requests_completed: AtomicU64,
+    pub requests_failed: AtomicU64,
+    pub total_prompt_tokens: AtomicU64,
+}
+
+impl PerfCounters {
+    pub fn new() -> Arc<Self> {
+        Arc::new(Self::default())
+    }
+
+    pub fn inc_tokens(&self, n: u64) {
+        self.tokens_generated.fetch_add(n, Ordering::Relaxed);
+    }
+
+    pub fn inc_completed(&self) {
+        self.requests_completed.fetch_add(1, Ordering::Relaxed);
+    }
+
+    pub fn inc_failed(&self) {
+        self.requests_failed.fetch_add(1, Ordering::Relaxed);
+    }
+
+    pub fn snapshot(&self) -> CountersSnapshot {
+        CountersSnapshot {
+            tokens_generated: self.tokens_generated.load(Ordering::Relaxed),
+            requests_completed: self.requests_completed.load(Ordering::Relaxed),
+            requests_failed: self.requests_failed.load(Ordering::Relaxed),
+            total_prompt_tokens: self.total_prompt_tokens.load(Ordering::Relaxed),
+        }
+    }
+}
+
+#[derive(Debug, Clone, serde::Serialize)]
+pub struct CountersSnapshot {
+    pub tokens_generated: u64,
+    pub requests_completed: u64,
+    pub requests_failed: u64,
+    pub total_prompt_tokens: u64,
+}