Messages chat polling freezes the browser

[jimlinntu]

Steps to reproduce

1. Type the text I want to search in the Nextcloud unified search box
2. Click one of the search result

Expected behaviour

The expected behaviour should be my focus will be on the search result I click.
But it turned out I was still in the same place.
I think the potential reason might be the text messages are too long.

Actual behaviour

The focus was still at the same place

Talk app

Talk app version: (see apps admin page: /index.php/settings/apps)
11.3.1

Browser

Operating system: macOS

Browser name: Chrome

Browser version: 91.0.4472.164

Browser log

Server configuration

Operating system: Ubuntu/RedHat/...

Web server: Apache/Nginx

Database: MySQL/Maria/SQLite/PostgreSQL

PHP version: 7.2/7.3/7.4

Nextcloud Version: (see admin page)

List of activated apps:

Details

If you have access to your command line run e.g.:
sudo -u www-data php occ app:list
from within your server installation folder

Nextcloud configuration:

Details

If you have access to your command line run e.g.:
sudo -u www-data php occ config:list system
from within your Nextcloud installation folder

Server log (data/nextcloud.log)

Details

Insert your server log here

[jimlinntu]

It seems related to this statement?

spreed/src/components/MessagesList/MessagesList.vue

Lines 426 to 428 in 90e0c72

	// TODO: in case the element is not in a page but does exist in the DB,
	// we need to scroll up / down to the page where it would exist after
	// loading said pages

[jimlinntu]

No offense here. I understand this feature may be still in progress.
But wouldn't you think if we cannot focus on the exact position if that text is not present on the current page,
isn't the unified search engine basically not really effective in this use case?

[PVince81]

@jimlinntu there's some logic missing that would need to find out how far to scroll up to load previous pages before focussing.

So if you search for a term that is present in the latest pages, the focus should work.
Otherwise you'll run into this issue.

This indeed makes search not that useful currently

[PVince81]

Now thinking, the current logic uses the "last unread message" as the separator between "fetch one page of old messages" and "fetch all new messages". Maybe when the hash in the URL contains a message, we could use that message id instead.

It also means that if the message in question is a million pages in the past, the "fetch all new messages" logic will take a while.
We'll also need to fix the "fetch all new messages" logic to be paginated, basically just fetch 1-2 pages of new messages and stop there until the user scrolls down.

[jimlinntu]

Thanks for your explanation!

Can you elaborate more about what are the main challenges of "fetch 1-2 pages of messages in question and fetch more only when the use scroll down or up"?
Are these challenges caused by backend database or purely frontend challenges?

[PVince81]

With the current logic, if we don't fetch all messages to the bottom, it will conflict with the logic that "long polls for new messages".
Should new messages appear in the chat if not scrolled to bottom ? Probably not I guess.

And possibly more potential issues, like sticky mode when scrolled to the bottom of that chat window.
There might be more I'm not aware of.

It's not trivial as there's a risk to break existing logic which might need to be redone/rethought.

[jimlinntu]

Can you point out:

• Where is the "long polls for new messages" code? (and as far as you know, how Facebook Messenger handles
• What is the sticky mode and where is the code of that?

I am just interested in that.

Perhaps if given more information, I might be able to help with this feature.

If you have more time, do you mind explaining:

• what's the current implementation in Nextcloud Talk different from Facebook Messenger in terms of the search feature?
• Is the implementation mainly inside: https://github.com/nextcloud/spreed/tree/master/src/components/MessagesList ?

[PVince81]

@jimlinntu you can start reading here: https://github.com/nextcloud/spreed/blob/master/src/components/MessagesList/MessagesList.vue#L450

this is what happens when the message list needs an update due to switching conversations

it will first fetch the old messages getOldMessages based on the indicators "first know message id" and "last known message id".

Then later below it calls lookForNewMessages which:

• if the last know message id is not the last message from the chat: it will pull all messages (or up to 200) after "last known message id"
• if the last known message id is the same as last message, it means all messages were fetched already, so the backend will keep the connection open in a "long poll" mode. as soon as new messages come in, it will send them back and close the connection. The long poll has a timeout.

Also, if you look more closely, you can see that lookForNewMessages will be called again and again to make sure we always have the long poll in place.

Regarding similarities of search with Facebook Messenger, I don't know, sorry.