[Buildsystem] Prevent cache check mangling access time

[AThousandShips]

Checking for text files using open changes atime, which breaks cache access sorting, this ensures the cache access time is preserved.

From looking at the code (without testing) this seems to be a regression from:

• SCons: Improve cache purging logic #98154

So shouldn't affect older versions but haven't tested explicitly there for access time issues

[AThousandShips]

This could be replaced by having another way to handle the checking for text files, but I'm not aware of one. Couldn't find any way to use open or similar without updating atime, if there is that would be more useful here

[dustdfg]

This could be replaced by having another way to handle the checking for text files, but I'm not aware of one. Couldn't find any way to use open or similar without updating atime, if there is that would be more useful here

Myabe os.stat would work? You can then set atime with os.utime I've should look on changes before writing comment. sorry

[dustdfg]

And another question. Maybe cache should rely on mtime? Not on atime?

[AThousandShips]

That's my solution? Or what do you mean? Please check the code

It shouldn't rely on mtime because then it'll ignore older, but more recently used, cache entries, cache entries that were read but not written to

[Repiteo]

Thanks!

[AThousandShips]

Thank you!