On Mon, 01 Nov 2021 10:36:08 -0500, Scott Cheloha wrote:
> My own testing here with pathological inputs didn't show that large of
> a performance difference between fgets(3) and getline(3). There was
> a difference but it was closer to like 5-10%.
With your updated patch I see:
% wc -l /tmp/z
10000000 /tmp/z
% /usr/bin/time uniq /tmp/z > /dev/null
0.48 real 0.49 user 0.00 sys
% /usr/bin/time ./obj/uniq /tmp/z > /dev/null
0.53 real 0.52 user 0.00 sys
which seems perfectly reasonable to me.
It may make sense to preallocate prevline and thisline to 8K to
avoid reallocating in the common case where there are lines of
varying sizes.
Also, I don't think there is any point in the free(prevline); before
exit when the initial getline() fails.
- todd
