The previous commit made this possible, so utilize it.
Since legacy.py becomes pretty bare, I inlined it into __init__.py. I'm
not sure it's really "legacy" anyway!
Using a simple 50000 items benchmark with `--collect-only -k nomatch`:
Before (two commits ago):
======================== 50000 deselected in 10.31s =====================
19129345 function calls (18275596 primitive calls) in 10.634 seconds
Ordered by: cumulative time
ncalls tottime percall cumtime percall filename:lineno(function)
1 0.001 0.001 2.270 2.270 __init__.py:149(pytest_collection_modifyitems)
1 0.036 0.036 2.270 2.270 __init__.py:104(deselect_by_keyword)
50000 0.055 0.000 2.226 0.000 legacy.py:87(matchkeyword)
After:
======================== 50000 deselected in 9.37s =========================
18029363 function calls (17175972 primitive calls) in 9.701 seconds
Ordered by: cumulative time
ncalls tottime percall cumtime percall filename:lineno(function)
1 0.000 0.000 1.394 1.394 __init__.py:239(pytest_collection_modifyitems)
1 0.057 0.057 1.393 1.393 __init__.py:162(deselect_by_keyword)
The matching itself can be optimized more but that's a different story.
c714f05ad7