This commit implements 2 new metrics/stats in the /about page for the _estimated_ numbers of unique visitors from the EU and the rest of the world. This new feature is currently off by default, but it can be enabled by turning on the hidden `display_eu_visitor_stats` site settings via the rails console.
There are a number of assumptions that we're making here in order to estimate the number of unique visitors, specifically:
1. we're assuming that the average of page views per anonymous visitor is similar to the average number of page views that a logged-in visitor makes, and
2. we're assuming that the ratio of logged in visitors from the EU is similar to the ratio of anonymous visitors from the EU
Discourse keeps track of the number of both logged-in and anonymous page views, and also the number of unique logged-in visitors and where they're from. So with those numbers and the assumptions above, we can estimate the number of unique anonymous visitors from the EU and the rest of the world.
Internal topic: t/128480.
Our 'page_view_crawler' / 'page_view_anon' metrics are based purely on the User Agent sent by clients. This means that 'badly behaved' bots which are imitating real user agents are counted towards 'anon' page views.
This commit introduces a new method of tracking visitors. When an initial HTML request is made, we assume it is a 'non-browser' request (i.e. a bot). Then, once the JS application has booted, we notify the server to count it as a 'browser' request. This reliance on a JavaScript-capable browser matches up more closely to dedicated analytics systems like Google Analytics.
Existing data collection and graphs are unchanged. Data collected via the new technique is available in a new 'experimental' report.
Using `create_or_find_by!`, followed by `update_all!` requires two or three queries (two when the row doesn't already exist, three when it does). Instead, we can use postgres's native `INSERT ... ON CONFLICT ... DO UPDATE SET` feature to do the logic in a single atomic call.
The #pluck_first freedom patch, first introduced by @danielwaterworth has served us well, and is used widely throughout both core and plugins. It seems to have been a common enough use case that Rails 6 introduced it's own method #pick with the exact same implementation. This allows us to retire the freedom patch and switch over to the built-in ActiveRecord method.
There is no replacement for #pluck_first!, but a quick search shows we are using this in a very limited capacity, and in some cases incorrectly (by assuming a nil return rather than an exception), which can quite easily be replaced with #pick plus some extra handling.
Adds stats for API and user API requests similar to regular page views.
This comes with a new report to visualize API requests per day like the
consolidated page views one.
Previously cached counting made redis calls in main thread and performed
the flush in main thread.
This could lead to pathological states in extreme heavy load.
This refactor reduces load and cleans up the interface
This reverts commit 20780a1eee.
* SECURITY: re-adds accidentally reverted commit:
03d26cd6: ensure embed_url contains valid http(s) uri
* when the merge commit e62a85cf was reverted, git chose the 2660c2e2 parent to land on
instead of the 03d26cd6 parent (which contains security fixes)
Doing .pluck(:column).first is a very common pattern in Discourse and in
most cases, a limit cause isn't being added. Instead of adding a limit
clause to all these callsites, this commit adds two new methods to
ActiveRecord::Relation:
pluck_first, equivalent to limit(1).pluck(*columns).first
and pluck_first! which, like other finder methods, raises an exception
when no record is found
