Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

events: Faster ascending array index #3976

Closed
wants to merge 5 commits into from
Closed

events: Faster ascending array index #3976

Changes from all commits
Commits
Show all changes
5 commits
Select commit Hold shift + click to select a range
87ec5f4
Faster ascending array index
alemures Nov 23, 2015
8f39c9e
New revision of arrayClone in events.js using for or slice depending …
alemures Nov 24, 2015
66dd7c7
Added comment to new version of arrayClone in events.js
alemures Nov 24, 2015
3b899ed
Added Comment to for loop and else if was replaced by if so the code…
alemures Nov 30, 2015
17677e0
After a discussion, 27 seems a better choice than 50 as the magic num…
alemures Jan 18, 2016
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
22 changes: 17 additions & 5 deletions lib/events.js
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -426,9 +426,21 @@ function spliceOne(list, index) {
list.pop();
}

function arrayClone(arr, i) {
var copy = new Array(i);
while (i--)
copy[i] = arr[i];
return copy;
// As of node.js v5.4.1 (v8 v4.6.85.31) benchmarks showed, a simple for
// loop performs better than Array#slice() for arrays smaller than 27
// elements, it is worth it, because it's more likely to use EventEmitters
// with a small number of listeners.
function arrayClone(arr, length) {
if (length === 1) {
return [arr[0]];
}

if (length < 27) {
var copy = new Array(length);
for (var i = 0; i < length; i++)
copy[i] = arr[i];
return copy;
}

return arr.slice();
}