I have a function that gets called a lot (a wanted function for File::Find going against large numbers of files). To avoid constantly hitting the disk, I do one stat/lstat and then use -X _ repeatedly after that (using the cached results of the last stat/lstat).

In some cases, I need to call other functions that need to be able to use stat/lstat, which will overwrite the cached results in _. The actual calls to these other functions are uncommon in frequency (exception handling, essentially), but there are many places in the main function that might need to call them.

Ideally, I would like to be able to localize the cached results of the stat/lstat call in some way (in the called functions). Is there a way to do this? (Note that local _; doesn't compile and local *_; doesn't work.) Is there a better and/or more generic approach?

If I can't localize in any way, one approach I'm considering is caching the results I need in a hash. For example:

#NOTE: Depending on certain conditions, I need either stat or lstat.
if (...) { stat($Filename) } else { lstat($Filename) }

#Current code uses this format:
# if (-X _) {...}

#Possible new code (including only the tests I need to use):
my %Stat =
(
r => (-r _),
w => (-w _),
x => (-x _),
s => (-s _),
...
);
if ($Stat{r}) {...}

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Thoughts?

In reply to Is it possible to localize the stat/lstat cache? by bounsy

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