From 984153b90a4e07983e9793ca83d6bb1ae628334b Mon Sep 17 00:00:00 2001
From: evgeny <evgeny@adaptto.ru>
Date: Sun, 11 Oct 2026 13:55:26 +0200
Subject: [PATCH] Expose monotonic age of verified substream progress

---
 src/stream/stream_metrics.c | 1 +
 src/stream/stream_metrics.h | 1 +
 2 files changed, 2 insertions(+)

diff --git a/src/stream/stream_metrics.c b/src/stream/stream_metrics.c
index fb59715b..c5b54d7a 100644
--- a/src/stream/stream_metrics.c
+++ b/src/stream/stream_metrics.c
@@ -104,6 +104,7 @@ int stream_metrics_poll(struct stream_metrics *m, uint64_t now_ms, struct stream
     metrics_detect_stop(m, now_ms);
     result.lag_ms = m->lag_ms;
     result.expected_interval_ms = m->expected_interval_ms;
+    result.progress_age_ms = now_ms - m->last_receive_ms;
     result.stopped = m->stopped;
     if (!m->ended && now_ms - m->last_receive_ms > m->expected_interval_ms)
         result.lag_ms = metrics_add(result.lag_ms, now_ms - m->last_receive_ms - m->expected_interval_ms);
diff --git a/src/stream/stream_metrics.h b/src/stream/stream_metrics.h
index a8b35ca1..1dae47ce 100644
--- a/src/stream/stream_metrics.h
+++ b/src/stream/stream_metrics.h
@@ -45,6 +45,7 @@ struct stream_metric_snapshot {
     uint64_t source_rate_bytes_sec;
     uint64_t receive_rate_bytes_sec;
     uint64_t expected_interval_ms;
+    uint64_t progress_age_ms; /* Монотонный возраст последнего реально принятого блока; известен при успешном poll. */
     int stopped;
     int source_rate_valid;
     int receive_rate_valid;