added gpr speed tracking

python_app/orchestration/shm/binary_cursor.py

@@ -48,3 +48,7 @@ class ByteCursor:
         data = self.payload[self.offset : self.offset + size]
         self.offset += size
         return data
+
+    def remaining_bytes(self) -> int:
+        """Return unread byte count."""
+        return len(self.payload) - self.offset

python_app/orchestration/shm/decoder.py

@@ -54,7 +54,21 @@ def decode_trace_collection(payload: bytes, expected_magic: int) -> SweepCollect
             )
         )
 
-    return SweepCollection(collection_id=collection_id, monotonic_ns=monotonic_ns, traces=traces)
+    capture_start_ns = 0
+    capture_end_ns = 0
+    if cursor.remaining_bytes() == 16:
+        capture_start_ns = cursor.read_u64()
+        capture_end_ns = cursor.read_u64()
+    elif cursor.remaining_bytes() != 0:
+        raise ValueError("Unexpected trailing bytes in trace collection")
+
+    return SweepCollection(
+        collection_id=collection_id,
+        monotonic_ns=monotonic_ns,
+        traces=traces,
+        capture_start_ns=capture_start_ns,
+        capture_end_ns=capture_end_ns,
+    )
 
 
 def decode_result_collection(payload: bytes) -> ResultCollection: