JSONFile.jsm, a new module to help with serializing JSON to disk

[Paolo Amadini]

On 10/12/2016 10:18 AM, David Teller wrote:
> I understand. But since removing I/O from the main thread used to be my
> responsibility, and since I have measurements that show just how bad
> main thread I/O can be, I'm still pretty touchy about this :)

For the record, we already have another use case where we need
synchronous loading to migrate legacy code, and that is the
replacement of the existing mimeTypes.rdf. It's already loaded
synchronously and we evaluated it's too much work to change all
the callers to be asynchronous. In that case we never use the
asynchronous loading at the same time though.

Before reading this thread I've already commented in bug 1309481 about
the need for specific tests and a few more protections for making this a
generic module. When I originally wrote it they weren't necessary.

Cheers,
Paolo