Rework radar system

python_app/orchestration/shm/ring_layout.py

@@ -0,0 +1,15 @@
+"""Shared ring layout; keep in sync with common_cpp/ipc/src/shm_ring.cpp."""
+
+from pathlib import Path
+import struct
+
+MAGIC = b"RDRRING2"
+VERSION = 1
+HEADER = struct.Struct("<8sIIIIQQQ16x")
+SLOT_HEADER_SIZE = 16
+
+
+def ring_path(name: str) -> Path:
+    if not name.startswith("/") or len(name) < 2 or "/" in name[1:] or "\x00" in name:
+        raise ValueError("ring_name must be '/' followed by a single nonempty filename")
+    return Path("/dev/shm") / name[1:]