Unify rosbag1 and rosbag2 connection class

src/rosbags/interfaces/__init__.py

@@ -0,0 +1,36 @@
+# Copyright 2020-2022  Ternaris.
+# SPDX-License-Identifier: Apache-2.0
+"""Shared interfaces."""
+
+from __future__ import annotations
+
+from typing import TYPE_CHECKING, NamedTuple
+
+if TYPE_CHECKING:
+    from typing import Optional, Union
+
+
+class ConnectionExtRosbag1(NamedTuple):
+    """Rosbag1 specific connection extensions."""
+
+    callerid: Optional[str]
+    latching: Optional[int]
+
+
+class ConnectionExtRosbag2(NamedTuple):
+    """Rosbag2 specific connection extensions."""
+
+    serialization_format: str
+    offered_qos_profiles: str
+
+
+class Connection(NamedTuple):
+    """Connection information."""
+
+    id: int
+    topic: str
+    msgtype: str
+    msgdef: str
+    md5sum: str
+    msgcount: int
+    ext: Union[ConnectionExtRosbag1, ConnectionExtRosbag2]