Node is freezing

[henryruhs]

Hello,

svg-term works perfect on my machine with the given 113643 example cast.

There seems to be an issue with new formats. I had to download my new cast in the version 1 syntax as svg-term told me that only version 1 and version 2 syntax are supported.

Watch cast: https://asciinema.org/a/znqFxSzM9CmIJINrmn2IzPX5g
Download JSON: https://asciinema.org/a/znqFxSzM9CmIJINrmn2IzPX5g.cast?dl=true

Setup

svg-term: 2.0.3
NodeJS: 8.7.0
NPM: 5.6.0
OS: Ubuntu 17.04

Command

svg-term --in 156579.json --out 156579.svg

svg-term --cast znqFxSzM9CmIJINrmn2IzPX5g --out 156579.svg

Issue

The terminal and sometimes my whole machine is freezing - there is no way to cancle it using CTRL+C. No output is being processed.

[marionebl]

Thanks for reporting, I'll investigate this over the next days

[marionebl]

Did the first steps to debug this, seems like load-asciicast enters an infinite loop for your asciicast. Will investigate further...

[henryruhs]

Great, it felt like a infinite loop :-) Looking forward to a fix, thank you man.

[marionebl]

Did a quick dirty test setup in svg-term

// svg-term/index.tsx#L81
console.log('load');
const cast = load(json, options.width, typeof options.height === 'number' ? options.height + 1 : undefined);
console.log('load', process.hrtime(start));

logs load and then freezes the process.

[bunopus]

Looks like it happens with the all new casts :-(

UPD: it's not true, not all casts affected

[marionebl]

@bunopus That’s not what I experience in daily usage. Could you provide the version of your asciinema cli and links to affected uploaded casts?

[bunopus]

@marionebl it's very strange

asciinema --version
asciinema 1.4.0

I have two casts with almost the same content, but one is working, second - not.
https://asciinema.org/a/eUnQPgWgKFVl4WUqinKbX7Qze - not working, svg-term-cli freezes
https://asciinema.org/a/D3qhyP1ORhqwL3yllRnnzHIbN - almost the same content - working

🤔

[marionebl]

Spent some more time on this. load-asciicast indeed does not enter an infinite loop, it just gets very very slow for certain casts:

cast	width	height	size	render time
156787	208	58	29K	145s
156838	112	32	28K	13s
156579	155	43	59K	> 300s

What jumped at me is the big dimensions. Forcing down the screen buffer size leads to notable speed increases:

cast	width	height	size	render time
156787	80	25	29K	5s
156838	80	25	28K	5s
156579	80	25	59K	11s

I'll create an issue with asciinema about this. For the time being you can force the screen buffer down via svg-term-cli:

svg-term --cast eUnQPgWgKFVl4WUqinKbX7Qze --out 156787.svg --width=80 --height=25
svg-term --cast znqFxSzM9CmIJINrmn2IzPX5g --out 156579.svg --width=120 --height=25