Overhaul stats: Simplify how the AnnounceHandler persist number of downloads in tracker-core package

[josecelano]

Simplify how the AnnounceHandler persist number of downloads in tracker-core package.

It's now done asynchronously instead of synchronously.

NOTICE: That bittorrent_tracker_core::announce_handler::AnnounceHandler::announce will not return a database error anymore, meaning the peer will receive the announce response even if the tracker can't update the downloads counter.

Subtasks

Main change:

• Scaffolding for listening to torrent-repository events in the tracker-core package.
• Move the SQL update from the AnnounceHandler to the event handler (handle_event).

Cleanup:

• Fix test. https://github.com/torrust/torrust-tracker/actions/runs/15168471742/job/42652507081?pr=1531#step:7:250
  • It's not the service's responsibility to increment the counter anymore. Add:
    • A unit test in the event handler to check that the counter is increased when the event is received.
    • An integration test to simulate a peer completing downloading.
    • Maybe we should also add a main app E2E test (to make sure the listener is initialised), but we are not testing it for other jobs directly. We have to review the strategy for E2E tests in the main app.
• Refactor: rename upsert_peer to handle_announcement.
• Refactor: rename AnnounceHandler::announce to AnnounceHandler::handle_announcement
• Refactor: Don't return the boolean number of downloads increased in upsert_peer. upsert_peer should only be a command decoupled from other secondary tasks. Side effects should be captured from events.

NOTE: I cannot remove the db_torrent_repository dependency from the AnnounceHandler yet until we implement the new persistent metric for the number of downloads, because it's still used in:

let opt_persistent_torrent = if self.config.tracker_policy.persistent_torrent_completed_stat {
    self.db_torrent_repository.load(info_hash)?
} else {
    None
};

[codecov]

Codecov Report

Attention: Patch coverage is 84.23645% with 32 lines in your changes missing coverage. Please review.

Project coverage is 83.88%. Comparing base (93f851d) to head (67d177b).
Report is 11 commits behind head on develop.

Files with missing lines	Patch %	Lines
...ages/tracker-core/src/statistics/event/listener.rs	57.14%	11 Missing and 1 partial ⚠️
...kages/tracker-core/src/statistics/event/handler.rs	56.00%	6 Missing and 5 partials ⚠️
src/bootstrap/jobs/tracker_core.rs	44.44%	4 Missing and 1 partial ⚠️
packages/udp-tracker-server/src/environment.rs	0.00%	2 Missing ⚠️
packages/http-tracker-core/src/services/scrape.rs	66.66%	0 Missing and 1 partial ⚠️
src/bootstrap/jobs/torrent_repository.rs	0.00%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #1531      +/-   ##
===========================================
- Coverage    83.92%   83.88%   -0.04%     
===========================================
  Files          267      270       +3     
  Lines        19207    19181      -26     
  Branches     19207    19181      -26     
===========================================
- Hits         16119    16090      -29     
- Misses        2811     2817       +6     
+ Partials       277      274       -3     

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[josecelano]

ACK 67d177b