Privacy preserving stats in Snowflake standalone proxy (Fix #40079)

This is a merge request aimed at adding additional log output to snowflake proxy in order to show aggregated result of traffic and user metrics. This is designed to allow users to get a positive feedback about their contribution to the Tor network.

The data collector reused the existing events interface designed for snowflake client. However, currently the client and server emits a disjoint set of events.

Things to look at:

• The summary interval is 1 hour by default(adjustable by user), this output will be easily shadowed by other outputs.
• There is no historic record by design. This is because there is no persistent storage, and it is expected that the proxy process being restarted from time to time. This ensure the data output is accurate and comparable. This also comes with the defensive design that prevent users from calculating resource consumption based on this data.

changed title from Privacy preserving stats in Snowflake standalone proxy (Fixes #40079 (closed)) to Privacy preserving stats in Snowflake standalone proxy (Fix #40079 (closed))

requested review from @meskio

Looks good to me, I have added a small comment, but feel free to merge it if you fix it or think that is best not to fix it.

approved this merge request

mentioned in commit shelikhoo/snowflake@e828b060

added 1 commit

• e828b060 - Use log instead of fmt in proxy event logger

Compare with previous version

resolved all threads

Great, I think is good to merge.

merged

mentioned in issue tpo/anti-censorship/docker-snowflake-proxy#7 (closed)

mentioned in issue #40302 (closed)