added capture time for every sweep

python_app/orchestration/shm/decoder.py

@@ -54,12 +54,27 @@ def decode_trace_collection(payload: bytes, expected_magic: int) -> SweepCollect
             )
         )
 
+    # Optional trailer, written after the trace blocks by newer producers: the
+    # collection capture window, then a per-trace window table. Both stages are
+    # optional so payloads from an older producer still decode (the timestamps
+    # simply stay zero).
     capture_start_ns = 0
     capture_end_ns = 0
-    if cursor.remaining_bytes() == 16:
+    if cursor.remaining_bytes() != 0:
+        if cursor.remaining_bytes() < 16:
+            raise ValueError("Truncated capture window in trace collection")
         capture_start_ns = cursor.read_u64()
         capture_end_ns = cursor.read_u64()
-    elif cursor.remaining_bytes() != 0:
+
+    if cursor.remaining_bytes() != 0:
+        trace_time_count = cursor.read_u32()
+        if trace_time_count != len(traces):
+            raise ValueError("Per-trace capture window count does not match trace count")
+        for trace in traces:
+            trace.capture_start_ns = cursor.read_u64()
+            trace.capture_end_ns = cursor.read_u64()
+
+    if cursor.remaining_bytes() != 0:
         raise ValueError("Unexpected trailing bytes in trace collection")
 
     return SweepCollection(