Multiple Readers and Writers in File System Access API

[nathanmemmott]

WebKittens

@annevk @szewai

Title of the spec

Multiple Readers and Writers in File System Access API

URL to the spec

https://fs.spec.whatwg.org/

URL to the spec's repository

https://github.com/whatwg/fs/

Issue Tracker URL

No response

Explainer URL

https://github.com/whatwg/fs/blob/main/proposals/MultipleReadersWriters.md

TAG Design Review URL

w3ctag/design-reviews#845

Mozilla standards-positions issue URL

mozilla/standards-positions#861

WebKit Bugzilla URL

No response

Radar URL

No response

Description

Currently, only one FileSystemSyncAccessHandle may be open at a time per file, preventing an origin from reading the same file from multiple tabs easily. Conversely, multiple FileSystemWritableFileStream can be simultaneously open, letting multiple writers clobber each other.

Introducing new “create” modes for FileSystemSyncAccessHandle and FileSystemWritableFileStream allows opening either multiple readers/writers or an exclusive writer to a file entry, depending on the application's use case.

handle.createSyncAccessHandle({ mode: 'read-only' });
handle.createWritable({ mode: ‘exclusive’ });