Big files without linebreaks should not crash

[giovannicimolin]

Check for existing issues

• Completed

Describe the bug / provide steps to reproduce it

When trying to open a big JSON file, Zed should not freeze.

To reproduce:

Trying to open a 120MB GeoJSON file freezes the app, while VSCode loads the file quickly without any issues (with highlighting disabled).

Note: I can't upload files bigger than 25MB here, but I think any big JSON will cause this issue.

Environment

Zed: v0.146.5 (Zed)
OS: Linux Wayland manjaro unknown
Memory: 15.3 GiB
Architecture: x86_64
GPU: Intel(R) Xe Graphics (TGL GT2) || Intel open-source Mesa driver || Mesa 24.1.5-manjaro1.1

If applicable, attach your ~/Library/Logs/Zed/Zed.log file to this issue.

Zed.log

No logs, it just freezes.

[failable]

(with highlighting disabled).

Have a setting like large-file-warning-threshold in Emacs would be great. If the file is larger than the threshold, the file will be opened literally without any latency and issue.

[notpeter]

For me Zed is able to open a 1.2GB text file without crashing, so I wonder if this is JSON specific. Does Zed still crash if you rename the file from .json to .txt?

Zed performing poorly with buffers >16M lines long is a known issue:

• Text rendering has glitches for pathologically large files #5355

[wlinna]

For me Zed freezes and crashes for a 166 MiB JSON file just the same regardless of the file extension, so it's not JSON specific. But all that text is on one line, so it might have something to do with that

[kanielrkirby]

My guess is that this is to do with line length, and (unless one already exists), I think it simply needs a cap (like VSCode's editor.stopRenderingLineAt, and potentially editor.maxTokenizationLineLength).

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I have a .log (20MB) file, and around 200-300 lines down, there's a very long line (1,541,369 characters long), so as soon as I open the file it hangs and usually crashes outright (no extensions or custom settings).

I've done a couple tests in some other editors I frequently use:

• Helix Editor handles this by not rendering anything outside the visible part of the buffer (i.e., it runs fine until you reach that line and chugs along until it's back out of view).
• VSCode handles this with a default editor.stopRenderingLineAt and editor.maxTokenizationLineLength (and line wrapping by default).
• Both NeoVim and Vim do the same as Helix, but also implement wrapping by default.

Enabling line wrapping in Zed also does not seem to help the issue.

[wlinna]

I used jq to pre-format JSON, then I added .txt extension to prevent JSON parsing, and now I'm able to open the file in Zed.

It's not perfect though. Often Zed will crash at some point in time, and then there's the aforementioned rendering problem.