Rich Media parsing was previously handled on-demand with a 2 second HTTP request timeout and retained only in Cachex. Every time a Pleroma instance is restarted it will have to request and parse the data for each status with a URL detected. When fetching a batch of statuses they were processed in parallel to attempt to keep the maximum latency at 2 seconds, but often resulted in a timeline appearing to hang during loading due to a URL that could not be successfully reached. URLs which had images links that expire (Amazon AWS) were parsed and inserted with a TTL to ensure the image link would not break.
Rich Media data is now cached in the database and fetched asynchronously. Cachex is used as a read-through cache. When the data becomes available we stream an update to the clients. If the result is returned quickly the experience is almost seamless. Activities were already processed for their Rich Media data during ingestion to warm the cache, so users should not normally encounter the asynchronous loading of the Rich Media data.
Implementation notes:
- The async worker is a Task with a globally unique process name to prevent duplicate processing of the same URL
- The Task will attempt to fetch the data 3 times with increasing sleep time between attempts
- The HTTP request obeys the default HTTP request timeout value instead of 2 seconds
- URLs that cannot be successfully parsed due to an unexpected error receives a negative cache entry for 15 minutes
- URLs that fail with an expected error will receive a negative cache with no TTL
- Activities that have no detected URLs insert a nil value in the Cachex :scrubber_cache so we do not repeat parsing the object content with Floki every time the activity is rendered
- Expiring image URLs are handled with an Oban job
- There is no automatic cleanup of the Rich Media data in the database, but it is safe to delete at any time
- The post draft/preview feature makes the URL processing synchronous so the rendered post preview will have an accurate rendering
Overall performance of timelines and creating new posts which contain URLs is greatly improved.
This check was recently improved in Credo and it does make sense for readability.
The offending functions in Pleroma have been renamed and a couple missing the ? suffix have been fixed as well.
This type is not exported and usable. FlakeId intends to return the type as :uuid, so we replace it in the typespecs with Ecto.UUID.t() which assuages the dialyzer errors
e.g.,
lib/pleroma/bookmark.ex:25:unknown_type
Unknown type: FlakeId.Ecto.CompatType.t/0.
We were overzealous with matching on a raw error from the object fetch that should have never been relied on like this. If we can't fetch successfully we should assume that the collection is private.
Building a more expressive and universal error struct to match on may be something to consider.
I first focussed on getting things working
Now that they do and we know what tags there are, I put some thought in providing better names
I use the form <what_it_controls>_<what_it_allows_you_to_do>
:statuses_read => :messages_read
:status_delete => :messages_delete
:user_read => :users_read
:user_deletion => :users_delete
:user_activation => :users_manage_activation_state
:user_invite => :users_manage_invites
:user_tag => :users_manage_tags
:user_credentials => :users_manage_credentials
:report_handle => :reports_manage_reports
:emoji_management => :emoji_manage_emoji
Instead of `Pleroma.User.all_superusers()` we now use `Pleroma.User.all_superusers(:report_handle)`
I also changed it for sending emails, but there were no tests.
feld