improvement: improve performance

[IWANABETHATGUY]

i found a big performance issue when open a big vue project, and fix it , pass all test.

[IWANABETHATGUY]

the same project, after open a few .vue file, i profile it.
current version:

this_pr version

current updateOffsetMapping

pr updateOffsetMapping

[IWANABETHATGUY]

i hope this pr can be merged, so more people may benefit this improve @octref

[ktsn]

If the perf bottle neck is toFiltered, can we only change it? Looks like inlining for loop for to and 'this.'.length are unnecessary?

[IWANABETHATGUY]

If the perf bottle neck is toFiltered, can we only change it? Looks like inlining for loop for to and 'this.'.length are unnecessary?

Because the string literal length this. can be calculated before runtime. This will not cause extra overhead . I think that if there is no particular impact on readability, performance should be the most important consideration.

[ktsn]

According to your screen shot, there are no particular differences between them.

• for loop
  • 6.9ms vs. 7.6ms
• 'this.'.length
  • 1.4ms vs. 1.3ms

So I think we should keep them. We intentionally wrote as 'this.'.length to indicate what the offset is for.

[IWANABETHATGUY]

ok, i will do that

[IWANABETHATGUY]

@ktsn complete that

[ktsn]

Thank you!

[IWANABETHATGUY]

@ktsn please don't publish now, i found this pr could cause .vue file outline issue, i will check that out

[IWANABETHATGUY]

@ktsn i'm sorry, it's not a bug, it's my vscode config issue, it's ok now .👍