Replace single config.json with a buffer of files

[mikeseese]

This makes it so that we never have to rename a config.json.bak file over the current config.json file. This also reduces the chance of file writing collusion. This is to prevent corrupt config.json files

See nylas-mail-lives/nylas-mail#15 and nylas/nylas-mail#3382

[mikeseese]

this hardcoded 10 is the number of config.timestamp.json files to keep. we may want to put this in a variable instead of inline hardcode. we may also might want this to be configurable? /shrug

I figured 10 would be enough when I wrote this; I haven't ran into a case when all 10 are corrupt

[mikeseese]

Is this waiting on anything @bengotow?

[mikeseese]

FYI nylas-mail-lives/nylas-mail#134 and nylas-mail-lives/nylas-mail#141 are further implementations on top of this PR

[bengotow]

Hey! Awesome thanks—I haven't merged this yet because if it's possible, I'd rather figure out why the config.json file is becoming corrupt in the first place and fix that. (Doing an atomic write + replace should be safe, especially now that all the writes are done from the main process and not from each window separately.) So far there haven't been any reports of corrupt config.json files in the Mailspring fork, though it might just be that Account objects aren't changed nearly as often since sync happens outside the app.

[mikeseese]

I'm fairly certain it's due to several applications are making changes several times a minute to the same file. My best guess is you won't see this problem due to the different sync process. I'm going to close this PR for now

[foundry376-bot]

This pull request has been mentioned on Mailspring Community. There might be relevant details there:

https://community.getmailspring.com/t/mailspring-shows-wrong-subject/640/1