tinchoz49
commented
4 years ago you'll note the ridiculousness we use for for grabbing setTimeout that's because this is sometimes run in environments that don't have globals set, so we'd want to check for the presence of that method inside of a try catch since we also don't know what the global object will be named and we don't want an error about unknown variables.
Makes sense, I didn't notice that code before, I can update it to use that approach.
this would be a great pull on immediate
Yes, I can do a PR for immediate :)
but I'm not so sure about here especially because I'm not actually sure how much of a benefit you'll get, you may get up to 4 ms of latency reductions in certain apps, but that's a best case and since setTimeout is not used for recursive calls you're never going to get much more then that at a time. Plus this is latency not performance, those 4ms aren't going to be blocking anything.
I never have a latency issue before with this process.nextTick until I try to use level-js in the browser.
I started seeing that it takes seconds to iterate over a readable stream in leveldb and it seems that was caused by calling the process.nextTick here: https://github.com/nodejs/readable-stream/blob/master/lib/_stream_readable.js#L561
I did a repository with the results:
https://github.com/tinchoz49/level-bench
Using setTimeout takes around 4.5 seconds to iterate over 1000 items and using queueMicrotask 76 ms
calvinmetcalf
gsvarovsky
feross
ljharb
you'll note the ridiculousness we use for for grabbing setTimeout that's because this is sometimes run in environments that don't have globals set, so we'd want to check for the presence of that method inside of a try catch since we also don't know what the global object will be named and we don't want an error about unknown variables.
this would be a great pull on immediate but I'm not so sure about here especially because I'm not actually sure how much of a benefit you'll get, you may get up to 4 ms of latency reductions in certain apps, but that's a best case and since setTimeout is not used for recursive calls you're never going to get much more then that at a time. Plus this is latency not performance, those 4ms aren't going to be blocking anything.