Hi David,
thanks for your reply and confirming that there is no event for this, so the best option is to make a simple loop and test every few seconds if the download is completed I guess.
I also noticed that fetching takes significantly longer when microdescriptors are disabled temporarily when compared to adding UseMicrodescriptors 0 to the torrc file persistently and restarting the tor client.
Maybe simply because server descriptors are much larger than microdesc?
In both cases we fetch the same kind of descriptors.
1) torrc: UseMicrodescriptors 0 -> start tor -> fast to complete descriptor fetching
2) no torrc change -> start tor -> controller.set_conf('UseMicrodescriptors', '0') -> slow
Maybe (2) is slower because tor does not start the download directly after set_conf('UseMicrodescriptors', '0') is received.
kind regards, nusenu