benchmark: replace [].join() with ''.repeat() #12170
Conversation
nodejs-github-bot
added
the
benchmark
benchmark/es/string-repeat.js
Outdated
| bench.end(n); | ||
| } | ||
|
|
||
| assert.strictEqual([...str].length, size); |
There was a problem hiding this comment.
Why [...str].length instead of just str.length?
There was a problem hiding this comment.
It is unicode-proof, it counts code points, not char codes:
> '\ud83d\udc0e'.repeat(10).length
20
> [...'\ud83d\udc0e'.repeat(10)].length
10
benchmark/es/string-repeat.js
Outdated
|
|
||
| if (conf.mode === 'Array') { | ||
| bench.start(); | ||
| for (let i = 0; i < n; i++) str = new Array(size + 1).join(character); |
There was a problem hiding this comment.
I like this style but I think it's not widely used in the codebase.
Is it better to put the for body in the next line?
Also is it ok to use let in for loops like this now?
There was a problem hiding this comment.
I will wrap to conform.
It seems let in loops is mostly optimized now. At least they are rather common in tests or benchmarks.
Also add a benchmark to compare both ways to create strings.
|
New linter CI: https://ci.nodejs.org/job/node-test-linter/7990/ |
Also add a benchmark to compare both ways to create strings. PR-URL: #12170 Reviewed-By: Luigi Pinca <luigipinca@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com>
|
Landed in 74dc3bf |
Also add a benchmark to compare both ways to create strings. PR-URL: nodejs#12170 Reviewed-By: Luigi Pinca <luigipinca@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com>
|
lts? |
|
ping @vsemozhetbyt , should this be backported to v6.x? |
|
@gibfahn I am not sure. If we have some +1 I can try to backport though if this does not land cleanly. |
|
I suspect that it's not worth trying to backport any more complex performance improvements to v6.x, all the benchmarks will have to be rerun etc. Having said that, if anyone is willing to do the work, then by all means do backport perf improvements. |
Checklist
Affected core subsystem(s)
benchmark
This change is mostly for readability as the edited fragments are not performance-wise concerned. However, a benchmark to compare both ways of long string creation is added to be on the safe side.
Results of the added benchmark with the last
node.8.0.0-nightly20170402