profiling.sampling heatmap reads non-regular and oversized files

Bug description

The heatmap exporter in profiling.sampling reads source files named in a profile unconditionally via Path(filename).read_text(). It does not check whether the path is a regular file or whether the file size is reasonable.

When replaying a binary profile, a filename pointing to a device file (e.g. /dev/zero) causes unbounded memory growth. An oversized file has the same effect.

The fix adds an is_file() guard and a 10 MB size cap before reading, consistent with the binary reader hardening in gh-152718.

CPython versions tested on

main

Operating systems tested on

macOS

Linked PRs

• gh-153839

Inizia nell’esportatore della heatmap di profiling.sampling, dove i percorsi sorgente vengono letti con Path(filename).read_text(), e confronta l’irrobustimento del lettore binario di gh-152718. Il lavoro è completato quando i percorsi non regolari e i file oltre 10 MB non vengono letti; gh-153839 è già collegato come lavoro proposto.