Io capture

[tzanko-matev]

No description provided.

[github-actions]

Coverage Summary

Rust (lines)
76.9% covered (3,705 / 4,818 | 1,113 missed)

File	Lines	Miss	Cover
codetracer-python-recorder/crates/recorder-errors/src/lib.rs	157	7	95.5%
codetracer-python-recorder/src/code_object.rs	117	16	86.3%
codetracer-python-recorder/src/ffi.rs	191	19	90.1%
codetracer-python-recorder/src/lib.rs	15	15	0.0%
codetracer-python-recorder/src/logging.rs	478	80	83.3%
codetracer-python-recorder/src/monitoring/tracer.rs	794	221	72.2%
codetracer-python-recorder/src/policy.rs	240	48	80.0%
codetracer-python-recorder/src/runtime/activation.rs	117	9	92.3%
codetracer-python-recorder/src/runtime/frame_inspector.rs	148	63	57.4%
codetracer-python-recorder/src/runtime/io_capture/mod.rs	275	96	65.1%
codetracer-python-recorder/src/runtime/io_capture/unix.rs	273	86	68.5%
codetracer-python-recorder/src/runtime/logging.rs	15	4	73.3%
codetracer-python-recorder/src/runtime/mod.rs	1,214	186	84.7%
codetracer-python-recorder/src/runtime/output_paths.rs	98	16	83.7%
codetracer-python-recorder/src/runtime/thread_snapshots.rs	39	7	82.1%
codetracer-python-recorder/src/runtime/trace_writer_host.rs	72	27	62.5%
codetracer-python-recorder/src/runtime/value_capture.rs	102	66	35.3%
codetracer-python-recorder/src/runtime/value_encoder.rs	88	6	93.2%
codetracer-python-recorder/src/session.rs	118	118	0.0%
codetracer-python-recorder/src/session/bootstrap.rs	183	14	92.3%
Showing top 20 entries by missed lines (of 21 total).

Python (statements)
61.5% covered (112 / 182 | 70 missed)

File	Stmts	Miss	Cover
codetracer-python-recorder/codetracer_python_recorder/__init__.py	7	0	100.0%
codetracer-python-recorder/codetracer_python_recorder/__main__.py	59	59	0.0%
codetracer-python-recorder/codetracer_python_recorder/api.py	5	0	100.0%
codetracer-python-recorder/codetracer_python_recorder/auto_start.py	22	9	59.1%
codetracer-python-recorder/codetracer_python_recorder/formats.py	13	1	92.3%
codetracer-python-recorder/codetracer_python_recorder/session.py	76	1	98.7%

Generated automatically via generate_coverage_comment.py.

[alehander92]

very impressive: but a radical approach: can't we somehow monkey patch the internal place/code that produces the writes? maybe this approach covers more fully/cleanly some cases, but it still seems a bit heavier

on the other hand: not critical, maybe for the future, but to check the current approach: what about file/other kind of events(in the future: network and others?) wouldn't we need something different for them, or would a similar approach be possible

[tzanko-matev]

I don't think that we can monkeypatch. We would need to detect all calls to C functions which deal with IO. But what if they are not from the standard library? For example our Rust module can produce logging statements which such an approach cannot handle.

Here we just redirect the in, out and error streams and we capture everything that we see.

It is possible to be even more ambitious on Linux using BPF. We can hook to the read and write syscalls. This means that we can map IO to which thread caused it. I am working on a prototype POC to test this approach as well.

[alehander92]

ok, i have to try to understand it in more detail: will try to see/or ask next week; bpf sounds interesting, maybe it can help with the general case of IO events, but still not sure if we can match them to the actual step in the general case(and here)