localStorage values are limited to 10Mb

[nunomluz]

localStorage is still limited to 10Mb. After running a few tests, it throws a:

DOMException: Failed to execute 'setItem' on 'Storage': Setting the value of 'data' exceeded the quota.

Also reported in issue 897, which is closed.

• Electron version: 1.4.13
• Operating system: Windows 7

Expected behavior

No limit/quota

Actual behavior

Limited to 10Mb

How to reproduce

Run localStorage.setItem('data', (new Array(11*1024*1024)).join("x"));

[kevinsawicki]

The total storage can be over 10MB but a single value cannot be over 10MB.

Since localStorage is synchronous, saving large values may hang the application, can you elaborate on why you are saving values that large?

[nunomluz]

Thanks, @kevinsawicki . I'm using the redux-localstorage enhancer, which stores part of the app state in serialized JSON as a single key-value. It's not a common case, but with the current implementation I'm working on, it can exceed 10 Mb.
The app hanging is an issue, so I'll consider another approach that doesn't rely on localStorage. However, anyone using redux-localstorage might experience this issue if the persisted slice of the app state grows over time.

[imolorhe]

I have the same use case as mentioned by @nunomluz. My app's state is stored in localstorage. The app state is rehydrated upon initialization based on the stored state.

[SmileOffline]

You can use this library,

I worked very well in our project.

https://github.com/electron-userland/electron-json-storage

[jacobq]

Could anyone tell me how to start going about writing a patch for this in the upstream chromium package? It looks like it's related to these:

• dom_storage README.
• set_quota method
• dom_storage_cached_area.cc

Update: Actually, it looks like the value might be defined here, so we ought to be able to at least increase it to a very large number, if not modify the quota enforcement logic.
How does electron go about applying patches to this (assuming v4.x)? Part of the build? Time to dig into the docs?

[jacobq]

BTW, is the reason that localStorage.sizeTest = new Array(5*Math.pow(2,20)).fill('X').join('') fails (5Mi characters) even though the quota limit is 10MiB because each character is using 2 bytes (JS strings using UTF-16)?

[jacobq]

Looks like this should be fixed in master (#14104), but I am still seeing it in 4.0.0-nightly.20181010 and 4.0.0-beta.7 Perhaps the dom_storage... patch either isn't working or is no longer sufficient.
https://github.com/electron/electron/pull/14104/files#diff-4169ea3b0bcb7c100cdc446c32b576b6R9