Auto fetching

[strboul]

• Asynchronous fetching operation: fetching should be as fast as possible. (Need to resolve Use more async operations #22)

• If fetching isn't fast enough, do it in the background in a forked process invoked when the command is called.

• The time is Realtime Timer, not Monotonic, (borrowing here the nomenclature of systemd-timer), so the time is always ticking even when the machine is powered off.

Need to check the date and internal storage that auto-fetch has been done. For internal storage, maybe choose a path like ~/.config/git-substatus/state.json.

# state.json file (mirroring the data structure of config.json)
{
  "autoFetchHooks": [
    {
      "folders": ["/path/to/folder1", "path/to/folder2"],
      "lastRunDate": "2023-01-...", # last command run with autofetchhooks modified.
    }
  ]
}

Pseudocode.

if config.autoFetchHooks.minutes:
  if (now() > state.autoFetchHooks.lastRunDate
      and now + config.autofetchHooks.minutes > state.autoFetchHooks.lastRunDate):
    args.append('--fetch')
 

Create a config entry. (Need to resolve #7)

autoFetchHooks:
    minutes: 60 # after login, after every x minutes, command will be run with the `--fetch` flag. Only positive integers are allowed. Minimum value is `1`.