read_waveform spends too much time constructing hightime objects
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bug
- Dominant language
- Python
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- 592
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- Avg merge
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- Merged PRs (30d)
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Description
Profile results for read_waveform indicate that constructing hightime objects is a bottleneck. These profile results include the proposed fix for #843.
ncalls tottime percall cumtime percall filename:lineno(function)
73707 0.080 0.000 14.231 0.000 D:\dev\nidaqmx-python\generated\nidaqmx\_feature_toggles.py:148(wrapper)
18 0.000 0.000 11.648 0.647 D:\dev\nidaqmx-python\tests\benchmark\test_analog_stream_readers.py:78(test___analog_multi_channel_reader___read_waveform)
51991 0.252 0.000 10.998 0.000 D:\dev\nidaqmx-python\generated\nidaqmx\stream_readers\_analog_multi_channel_reader.py:140(read_waveforms)
51991 0.314 0.000 10.247 0.000 D:\dev\nidaqmx-python\generated\nidaqmx\_library_interpreter.py:6416(read_analog_waveforms)
3802 0.126 0.000 6.975 0.002 D:\dev\nidaqmx-python\generated\nidaqmx\_library_interpreter.py:6637(_set_waveform_timings)
24366 0.722 0.000 6.624 0.000 D:\dev\nidaqmx-python\.venv\lib\site-packages\hightime\_timedelta.py:43(__new__)
6 0.000 0.000 4.122 0.687 D:\dev\nidaqmx-python\generated\nidaqmx\_library_interpreter.py:6514(_internal_read_analog_waveform_per_chan)
6090 0.062 0.000 3.417 0.001 D:\dev\nidaqmx-python\.venv\lib\site-packages\hightime\_datetime.py:294(__add__)
24 0.000 0.000 2.883 0.120 D:\dev\nidaqmx-python\generated\nidaqmx\task\_task.py:1254(wait_until_done)
24 2.883 0.120 2.883 0.120 D:\dev\nidaqmx-python\generated\nidaqmx\_library_interpreter.py:5961(wait_until_task_done)
21716 0.055 0.000 2.863 0.000 D:\dev\nidaqmx-python\generated\nidaqmx\stream_readers\_analog_single_channel_reader.py:112(read_waveform)
1878658 1.887 0.000 2.848 0.000 C:\Users\Administrator\.pyenv\pyenv-win\versions\3.9.13\lib\fractions.py:62(__new__)
21716 0.105 0.000 2.784 0.000 D:\dev\nidaqmx-python\generated\nidaqmx\_library_interpreter.py:6374(read_analog_waveform)
414236/219308 0.204 0.000 1.808 0.000 {built-in method builtins.round}
6090 0.020 0.000 1.698 0.000 D:\dev\nidaqmx-python\.venv\lib\site-packages\hightime\_timedelta.py:221(__add__)
414222/219294 0.543 0.000 1.695 0.000 C:\Users\Administrator\.pyenv\pyenv-win\versions\3.9.13\lib\fractions.py:505(__round__)
131574 0.256 0.000 1.544 0.000 D:\dev\nidaqmx-python\generated\nidaqmx\_library_interpreter.py:6615(_invoke_callback)
Originally posted by @bkeryan in https://github.com/ni/nidaqmx-python/pull/842#discussion_r2380634836
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start with tests/benchmark/test_analog_stream_readers.py and the profiled read_waveforms, read_waveform, read_analog_waveforms, and _set_waveform_timings entries in generated/. Profile the benchmark to identify the hightime object construction path, then verify that the benchmark shows reduced time for waveform reads without changing their results.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- python
- Domain
- performance
- Issue type
- Refactor
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Needs clarification
- Newbie friendliness
- 35/100