Changed spawn() and the rerun script to call into rerun_bindings (12x startup time improvement)

rerun_py/pyproject.toml

@@ -40,7 +40,7 @@ homepage = "https://www.rerun.io"
 repository = "https://github.com/rerun-io/rerun"
 
 [project.scripts]
-rerun = "rerun.__main__:main"
+rerun = "rerun_bindings:main"
 
 [tool.ruff]
 # https://beta.ruff.rs/docs/configuration/

rerun_py/rerun_sdk/rerun/__main__.py

@@ -1,15 +1,17 @@
 """See `python3 -m rerun --help`."""
 from __future__ import annotations
 
-import sys
+import rerun_bindings as bindings
 
-from rerun import bindings, unregister_shutdown
+from rerun import unregister_shutdown
 
 
 def main() -> None:
     # We don't need to call shutdown in this case. Rust should be handling everything
+    # TODO(ab): we only do that because __init__.py was loaded and register_shutdown() was called.
+    # Ideally, nothing should be loaded at all but `rerun_bindings` when we run `python3 -m rerun`.
     unregister_shutdown()
-    exit(bindings.main(sys.argv))
+    exit(bindings.main())
 
 
 if __name__ == "__main__":

rerun_py/rerun_sdk/rerun_demo/__main__.py

@@ -50,7 +50,8 @@ def run_structure_from_motion(args):
         print(f"No demo file found at {rrd_file}. Package was built without demo support", file=sys.stderr)
         exit(1)
     else:
-        exit(bindings.main([sys.argv[0], str(rrd_file)] + serve_opts))
+        sys.argv = [sys.argv[0], str(rrd_file)] + serve_opts
+        exit(bindings.main())
 
 
 def main() -> None:

rerun_py/src/python_bridge.rs

@@ -59,7 +59,10 @@ fn global_web_viewer_server(
 }
 
 #[pyfunction]
-fn main(py: Python<'_>, argv: Vec<String>) -> PyResult<u8> {
+fn main(py: Python<'_>) -> PyResult<u8> {
+    let sys = py.import("sys")?;
+    let argv: Vec<String> = sys.getattr("argv")?.extract()?;
+
     let build_info = re_build_info::build_info!();
     let call_src = rerun::CallSource::Python(python_version(py));
     tokio::runtime::Builder::new_multi_thread()