D4148: perf: add a command to benchmark linelog edits

[quark (Jun Wu)]

quark added inline comments.

INLINE COMMENTS

> indygreg wrote in perf.py:904-912
> I'm a bit concerned about the use of random data in a benchmark. Since every run will be different, the benchmark may not be stable. And if the random source is slow, we could be spending time waiting on entropy.
> 
> Do you think it is worthwhile to precompute the arguments to `replacelines()` and have the benchmark simply iterate through a list of arguments and call `replacelines()` repeatedly?

I think `random.seed(0)` makes it stable?

Good point about pre-calculate randints. Will change.

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D4148

To: quark, #hg-reviewers
Cc: indygreg, mercurial-devel