The fixture was rebuilt and kept this time, and the same benchmark run against it with only the listing changed. Twenty thousand files: min 166 to 10 frames, median 184 to 12, max 598 to 48. Ten to twelve frames is 0.17-0.20 s, inside the range where an interaction reads as instant, against roughly three seconds before, and the outlier fell by a factor of twelve.
The doc is careful about what that measures: the test waits for file-0.txt, which is in the first batch, so those frames are time-to-first-rows. The other nineteen batches still take the ~2 s of readdir and stat described above - they simply arrive behind the progress bar, into a list the user is already scrolling. Both halves matter and only the first is in the table.
It also records the fixture policy that made this possible: --count reuses a folder that already holds at least that many files and --fresh rebuilds, because building twenty thousand files costs half an hour on this phone. Keeping it was the lesson I wrote down and then failed to follow twice.
SoftwareApp
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