We were queuing up individual messages to be flagged as
read on the server before this change, and we used debounce
to avoid sending individual POSTs, but this created delays
that were ripe for race conditions.
Now we batch them in the caller and use throttle instead.
This now prevents us from slamming the server with lots of
individual requests, without as many opportunities for races.
(Note that we still have some possibility of race conditions,
but they should be rare now, and other commits will address
some of the other contributors to read/unread glitches.)
In the JS code, we now use `message.unread` universally as
the indicator of whether a message is unread, rather than
the `message.flags` array that gets passed down to us
from the server.
In particular, we use the unread flag for filtering when
you search.
A lot of this commit is just removing logic to add/remove
"read" from `message.flags` and updating tests.
We also explicitly set `message.unread` to `false` inside of
`unread.mark_as_read()` and no longer have `unread.set_flag()`.
(Some of the callers to `unread.set_flag` were also calling
`unread.mark_as_read`, which was updating the `message`
object, so now we just have `unread.mark_as_read` update
the `message` object. And then unread_ops.mark_all_as_read()
was already calling unread.declare_bankruptcy().)
This adds two similar functions to simplify
our batch processing of unread messages.
unread.get_unread_messages
unread.get_unread_message_ids
They are used to simplify two functions that loop
over messages. Before this change, the functions
would short circuit the loop to ignore messages
that were already read; now they just use the
helpers before the loop.
The new endpoints are:
/json/mark_stream_as_read: takes stream name
/json/mark_topic_as_read: takes stream name, topic name
The /json/flags endpoint no longer allows streams or topics
to be passed in as parameters.
This change simplifies how we mark all messages as read. It also
speeds up the backend by taking advantage of our partial index
for unread messages. We also use a new statsd indicator.
This code adds 'read' to message.flags and sets message.unread
to false.
It's not clear that the boolean message.unread is used in any
meaningful way, but we set it to false to avoid confusion. The
bankruptcy code was not doing this before.
Another quirk that existed before was that you could get two
'read' flags in a message when you declared bankruptcy. It's
also plausible that this could happen if you marked a message
as read via two different ways. It probably did not cause
user-facing bugs, but it would be confusing for troubleshooting.
Fixes#5032.
The new method borrows some code from the event loop
and unread_ops.mark_messages_as_read, and it is now
flexible about message_ids being marked as unread
even when there is no corresponding message in the
message store. For that scenario we still want to
update our data structures, which wasn't happening
before this change. (Generally, this was a non-issue
up until now, but it will become a bigger issue when
we start loading unread message ids from the server.)
This function allows us to see whether unread.js thinks a message
id is unread (as opposed to looking at the message itself). This
method is useful when we get notifications from the server that a
message has been read. In the future, we may not actually have
a local copy of an unread message, but we'll still know that it is
unread based on page_params. We'll want to update the data in that
case.
Going forward, we'll want to deprecate message.flags for most use
cases and just use the unread.js data structures to track unread
messages.
Tim Abbott
Steve Howell
Steve Howell