utils: helper function to print top memory allocation site
The memorytop function uses Python's tracemalloc module to show the
source lines / backtraces with the largest remaining allocations. This
allows identifying the origins of active memory by placing calls in
strategic locations. Allocations from C extensions will show up as long
as they are using the Python allocators.
Differential Revision: https://phab.mercurial-scm.org/D9236
[tool.black]
line-length = 80
exclude = '''
build/
| wheelhouse/
| dist/
| packages/
| \.hg/
| \.mypy_cache/
| \.venv/
| mercurial/thirdparty/
'''
skip-string-normalization = true
quiet = true