Latex-workshop: Delay when pressing enter

[flxflx]

I just installed version 5.13.0 and I am now getting a long delay (2s?) when pressing enter. Disabling latex-workshop.bind.enter.key does not help. Thanks!

[tecosaur]

For solidarity, I've recently been getting this issue too. At least from 5.12.

Another interesting quirk with this – I've found that despite the issues getting enter to create a new line — if you expand snippets that include a new line it's instant and works fine. However, pasting new lines also has a long delay so I'm not sure quite what to make of this.

_Edit:_ Also, with regards to the length of the delay it seems dependent on two factors to me:

• how good the computer is. This is painful on my potato PC, and a slight irritation on my custom desktop
• how large the file is, seems like ∼2× the delay for my 2.5k file than my 1k

[arjunguha]

I am having the same issue. It seems to coincide with the release of VSCode 1.28.2, but that may be a coincidence.

[tecosaur]

Another thing I've found: Shift+Enter seems to work for some reason...

[jlelong]

Unfortunately, I cannot reproduce the problem on OS X.

[tecosaur]

Am I correct in guessing you've tried a large file?

[jlelong]

I have tried on a 56k tex file. Can you provide an example?

[tecosaur]

That's much larger than the files I am having an issue with, since this seems to be a PC/mac difference could it be something to do with vs code itself?
If you can tell us how to try an earlier version of LaTeX-Workshop we could try that and see if there's still an issue.

[James-Yu]

I just tried on two PC, one is a rotten potato, and no significant delay is observed. I am neither aware of what might be causing this.

[tecosaur]

I'm there some way to do something like performance analysis since Vs code
uses electron?

[arjunguha]

I tried this more systematically. I'm on macOS latest:

• There is no issue when LaTeX Workshop is the only extension loaded
• This problem only occurs when using LaTeX Workshop and Spell Right
• However, the problem does not occur when spell checking a plain text file. (i.e., if I change the extension from .tex to .txt, the delay on enter disappears).

So, it appears to be some sort of bad interaction between extensions. Other folks who have this issue: are you also using Spell Right (or some other spell-checker)?

[tecosaur]

As it so happens I am also using Spell Right. I'll update this comment with what happens when I disable it.
Update: I have done so, enter still had a noticeable delay while shift+enter did not.

[tecosaur]

Performance Analysis Part 1

Another tidbit, I used the performance profiley thingy and got this graph:

Every odd small hump (1st, 3rd, 5th, and 7th hump) correspands to me pressing a letter and enter and basically the same time, and the big bump is when all the enters are actually added.

Edit: Note — this was with _Spell Right_ disabled

[tecosaur]

Perormance Analysis Part 2

When new lines are inserted

The following refers to this section:

I noticed that the actual adding of the new lines seems to happen at the end of the purple blip. This corresponded to this function call:

And the call tree is … deep. Quite deep

Screenshots

When enter pressed (and before new line inserted)

The following refers to this section:

This is what the call tree looks like

Screenshots

Sorry about the scroling, hopefuly something here might be helpful, let me know if you want more detail on any of the events

[James-Yu]

Actually when Spell Right came out I tried it several times. In each time I was just bothered by the random delay you described. I have no idea what was causing that, and I highly suspect it was on the other side.

[tecosaur]

@James-Yu have you got any comment about what I found (Performance Analysis Pt1&2) because that was with _Spell Right_ Disabled.

[tecosaur]

Other relevant info

Since I have ∼60 extensions installed I thought it would be worth checking another file type to see if I still have this issue. I tried a 10k line javascript file. No noticeable lag whatsoever, delay previously observed on 2k line LaTeX files.

Conclusion

This is seems to be LaTeX specific.

[James-Yu]

Have you tried disabling all extensions except for this one?

[tecosaur]

Have tried. Result:

I retract my earlier statement, this isn't purely because of this extension. My best guess is that there are multiple extension-interaction type things contributing to this. I still find it odd that since it doesn't seem to be purely LaTeX workshop, that other file types didn't suffer from the same issue.

[James-Yu]

Unfortunately, until you or someone identified which extensions are fighting, I cannot proceed to debugging. A worse guess is that this might be an upstream vscode problem.

[tecosaur]

Some extensions which cause this issue

• Spell Right
• Brackets Pair Colouriser 2
• Prettify Symbols Mode

That's the list from me so far

Note

Also got 24 extensions running without noticeable impact

[bartosz-antosik]

Hello everyone.

I would eagerly try to have a look but would like to have some reference file that someone can declare as the one which suffers the delay when pressing Enter here or there.

I have edited multitude of LaTeX documents (using LaTeX Workhop) and have not noticed the issue. Maybe they were not big enough.

[tecosaur]

@bartosz-antosik try this:
test.tex.zip

[bartosz-antosik]

@James-Yu Please help! I have been staring at this issue for quite few hours and all the observations seem to be true: Once Latex Workshop is used alone no blocking at all, same with Spell Right used alone!

Once however I remove in onDidChangeTextDocument event (which seems to be the only thing I do around enter click) nothing changes - the delay is still there. Strange observation that when I log start and stop of processing in onDidChangeTextDocument event, they both start after substantial delay after the enter is pressed.

It could suggest that "there is something wrong in they part" but I have seen strange things.

Could you please have some thought on this from your POV please?

[James-Yu]

I'll look into it

[tamuratak]

Profiler says that RegExp.prototype.exec() called from _filter and _parse in vscode-spellright/lib/parsers/latex.js consumes the most of CPU time.

[bartosz-antosik]

@tamuratak Yes, I am aware about this, but: 1/ this time is linearly proportional to the size of the document, 2/ it does happen in every type of document spelled (so not LaTeX documents only) 3/ In This cooperation (Latex Workshop + Spel Right) this delay after ENTER key does not happen at every press of ENTER 4/ When I disable whole processing in onDidChangeTextDocument the delay persists 5/ It amounts to 1.4 second not over 5. Technically it is parsing for InDocument commands & some general cleanup before spelling (e-mails, www addresses etc.)

[tamuratak]

I think the following is the cause.

When pressing Enter key, a command latex-workshop.onEnterKey is queued. Until Spell Right finishes its job, and it takes very long time, VSCode waits to invoke the command. Then, we see a delay. When pressing Shift+Enter, a command latex-workshop.onEnterKey is not queued. Then we don't see the delay. For example, if we delete latex-workshop.onEnterKey in package.json, we don't see the delay.

[bartosz-antosik]

@tamuratak So it should not happen (or at least be limited to 1.4 second) once you set latex-workshop.onEnterKey to false?

[tamuratak]

No, it should not. Please try yourself.

[bartosz-antosik]

@tamuratak I did and I still have the delay.

[tamuratak]

1. Please uninstall all the other plugins except LaTeX-Workshop and Spell Right.
2. Paste the following to keybindings.json

    {
        "key": "enter",
        "command": "-latex-workshop.onEnterKey",
        "when": "editorTextFocus && !editorReadonly && !suggestWidgetVisible && !vim.active && editorLangId == 'latex'"
    },
    {
        "key": "enter",
        "command": "-latex-workshop.onEnterKey",
        "when": "editorTextFocus && vim.active && !editorReadonly && !suggestWidgetVisible && editorLangId == 'latex' && vim.mode == 'Insert'"
    }

1. See any delay?

[bartosz-antosik]

@tamuratak Last thing: Could you please elaborate a bit on why onEnterKey is queued? I do not get this as I do the same exactly thing in case of every onDidChangeTextDocument event and it does not seem to slow other extensions?

[tamuratak]

I cannot get your point. I want to know whether you still see any delay with only the two extensions.

[bartosz-antosik]

@James-Yu I think you may close this thread.

[tecosaur]

@bartosz-antosik can I take that to mean you've found a fix (and implemented it)?

[bartosz-antosik]

@tecosaur No. Fix is very complicated and will take time.

[tecosaur]

@bartosz-antosik I'm sorry to hear that. Can you confirm that a fix is on the horizon for the extension (I really don't want to stop using your extension)?

[bartosz-antosik]

@tecosaur Yes I am working on resolution.

[igor-krupenja]

@bartosz-antosik Is there an issue in SpellRight repo tracking this? Could not find one.

[felipecrp]

I think the following is the cause.

When pressing Enter key, a command latex-workshop.onEnterKey is queued. Until Spell Right finishes its job, and it takes very long time, VSCode waits to invoke the command. Then, we see a delay. When pressing Shift+Enter, a command latex-workshop.onEnterKey is not queued. Then we don't see the delay. For example, if we delete latex-workshop.onEnterKey in package.json, we don't see the delay.

Manually disabling these binds solved the problem.