Add prometheus exporter on :9100

cmd/collector/store.go

@@ -13,6 +13,7 @@ const liveMapCap = 100_000 // hard cap on live map entries
 // Store holds the live map and both ring buffers.
 type Store struct {
 	source string
+	prom   *PromStore // optional; if non-nil, receives every ingested record
 
 	// live map — written only by the Run goroutine; no locking needed on writes
 	live    map[st.Tuple6]int64
@@ -41,9 +42,12 @@ func NewStore(source string) *Store {
 	}
 }
 
-// ingest records one log record into the live map.
+// ingest records one log record into the live map and the Prometheus store (if set).
 // Must only be called from the Run goroutine.
 func (s *Store) ingest(r LogRecord) {
+	if s.prom != nil {
+		s.prom.Ingest(r)
+	}
 	key := st.Tuple6{Website: r.Website, Prefix: r.ClientPrefix, URI: r.URI, Status: r.Status, IsTor: r.IsTor, ASN: r.ASN}
 	if _, exists := s.live[key]; !exists {
 		if s.liveLen >= liveMapCap {