A video's preview and a picture's thumbnail are made inside the request that posts the message, and
nothing bounded how long either could take.
- The video preview filter also selects any frame from 5 seconds on. Rails' filter takes the second
frame it selects, which a video with a single keyframe and no scene change only gives at its end, so
ffmpeg decoded all of it.
- TimeLimitedVideoPreviewer gives ffmpeg 10 seconds of wall-clock time, kills it past that, and reports
a failed preview, so the message is posted without one.
- Pictures and videos above 250 megapixels, or whose size couldn't be read, get no preview: decoding
costs in proportion to the pixels, however small the file.
- The view shows a preview only if it was made when the message was posted. Its URL used to make it on
view, so a preview that failed or was skipped would be attempted again on every view. The cached
presentation's version goes up, so cached messages pick this up.
- A video's poster is made, when the message is posted, at the size the view shows it. The full-size WebP
made until now wasn't shown anywhere, and encoding it costs in proportion to the frame's pixels.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Bj8KnxpTf9sj2Ysa8aLAVa
The thumbnail or video preview is generated while the message is posted.
When ffmpeg or libvips can't decode the file (a truncated upload, an .mp4
holding only audio), the error escaped after the message had been saved:
the request failed with a 500, the message was never broadcast, and the
sender's upload stayed at 100% while the rest of the files in that drop
were never sent. Posting the message without a preview keeps the file and
lets everyone see it.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JVFo3Lt9T8M5NR7KxVvsZ2
Search showed the last 100 matches by created_at, so SQLite collected every
message containing the words and sorted them before keeping a page. A common
word in a large account meant sorting most of its history on every search.
Ordering by the full-text index's rowid, which is the message id, lets SQLite
walk the index from the newest match and stop once the page is full.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JVFo3Lt9T8M5NR7KxVvsZ2
The search box keeps only word characters, but FTS5 still reads AND, OR,
NOT and NEAR in the query as operators, so searching for "AND" or for
"salt AND" raised "fts5: syntax error" and answered with a 500. Quoting
each word makes FTS5 look for it as text, which is how it already treats
the same words in lower case.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NuTtwJKhb77Dv7EQqv2C3C
The original room shows its welcome box until it holds more than a page of
messages, and paged? answered that with a COUNT(*) over every message in
the room on each visit. Asking whether there is a row past the first page
answers the same question while reading at most a page of index entries.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NuTtwJKhb77Dv7EQqv2C3C
* Preload only uncached messages and reduce rendering overhead
* Keep benchmark summaries without raw JSON results
* Use Ruby benchmark drivers and keep generated results out of the repo
UnreadRoomsChannel streamed from a hardcoded global name, and every message
published its room id to it. Any authenticated user, including one with no
memberships at all, could subscribe and watch which rooms were active and exactly
when, across every closed room and direct conversation on the account. The browser
filters ids it doesn't recognise, but that happens after delivery.
Its sibling ReadRoomsChannel is already scoped per user; this mirrors it, and
message creation fans the notice out to the room's members instead of broadcasting
it to everyone. No message content was exposed either way, only the timing.
This adds the ability to ban a user by their IP address.
When an admin is viewing a user profile, a new "Ban user" button is
present. Clicking on that will:
- Create a ban on the IP addresses that were tracked for that user's
sessions
- Remove all the messages authored by that user
- Log the user out immediately
In addition, that user will no longer be shown in most user lists in the
app. They are still shown to admins, in account settings. Viewing their
profile from there will now show a "Remove ban" button which can be used
to restore their access (it doesn't restore their messages though --
those are already gone -- it just removes the blocks so they can log in
again).