Fix RecordingStream so it has a unique recording id when none is provided

Source-Ref: 126fbcc2ca36a96a7b037b20e972a0239d8e94f8

Author: abey79

rerun_py/rerun_sdk/rerun/__init__.py

@@ -178,7 +178,7 @@
 from .recording_stream import (
     BinaryStream as BinaryStream,
     ChunkBatcherConfig as ChunkBatcherConfig,
-    RecordingStream as RecordingStream,
+    RecordingStream as RecordingStream,  # noqa: TC001
     binary_stream as binary_stream,
     get_application_id as get_application_id,
     get_data_recording as get_data_recording,
@@ -350,13 +350,15 @@ def init(
         recording_id = str(recording_id)
 
     if init_logging:
-        RecordingStream(
+        # Note: don't use `RecordingStream` here, because it overrides the default recording id behavior
+        bindings.new_recording(
             application_id=application_id,
             recording_id=recording_id,
             make_default=True,
             make_thread_default=False,
             default_enabled=default_enabled,
             send_properties=send_properties,
+            batcher_config=None,
         )
 
     if spawn:

rerun_py/rerun_sdk/rerun/recording_stream.py

@@ -310,6 +310,12 @@ def __init__(
 
         if recording_id is not None:
             recording_id = str(recording_id)
+        else:
+            # We must absolutely avoid passing a None value to the bindings, because this will trigger the behavior
+            # where it attempts to use the same recording id for parallel streams in the same process. When a
+            # `RecordingStream` is explicitly created, the reuse of a recording id is not at all expected, though.
+            # TODO(RR-1154): this is yet another consequence of stateless APIs not being first class
+            recording_id = uuid.uuid4().hex
 
         self.inner = bindings.new_recording(
             application_id=application_id,

rerun_py/tests/unit/test_multi_stream.py

@@ -29,6 +29,18 @@ def test_init_twice() -> None:
     assert recording_id == rr.get_recording_id()
 
 
+def test_recording_stream_twice() -> None:
+    """For `RecordingStream`, the default should be to have new, unique recording ids."""
+
+    with rr.RecordingStream("rerun_example_bug") as rec:
+        id1 = rec.get_recording_id()
+
+    with rr.RecordingStream("rerun_example_bug") as rec:
+        id2 = rec.get_recording_id()
+
+    assert id1 != id2
+
+
 def test_isolated_streams(tmp_path: Path) -> None:
     rec1_path = f"{tmp_path}/rec1.rrd"
     rec2_path = f"{tmp_path}/rec2.rrd"