[dumbo-octopus]

It's 4 async calls, and it can be done entirely in the main thread so long as you use the async API. https://developer.mozilla.org/en-US/docs/Web/API/FileSystemW...

[jampekka]

For OPFS it's still 6 calls. And the async API doesn't support flushing writes.

https://developer.mozilla.org/en-US/docs/Web/API/File_System...