fix: lower threshold for system address book sync

[kesselb]

Summary

• Switch back to countUsers to have the actual value. countSeenUsers is bad if Nextcloud is connected to a larger directory, but only a part is using Nextcloud and therefore the seen count is much lower because the sync is done for all users.
• Lower the threshold to 100

TODO

• CI

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)

[ChristophWurst]

if countSeenUsers() is faster you can do a combined condition. something like if (countSeenUsers() > 100 || countUsers() > 100)

this means countUsers is called only for user backends that don't support counting, or where seen users is lower 100 while actual users is above

@miaulalala anything I'm missing? this is what we defined a few weeks ago

[kesselb]

Yep, that's cool 👍

countSeenUsers
select count(userid) from oc_preferences where appid = 'login' and configkey = 'lastLogin';

countUsers

Database:

server/lib/private/User/Database.php

Lines 468 to 476 in 1cd4d4e

	public function countUsers() {
	$this->fixDI();
	$query = $this->dbConn->getQueryBuilder();
	$query->select($query->func()->count('uid'))
	->from($this->table);
	$result = $query->executeQuery();
	return $result->fetchOne();

SAML: https://github.com/nextcloud/user_saml/blob/b8d0ed551752d2e1ef23a8fac26424b1d067b91c/lib/UserBackend.php#L674-L677
LDAP: Is usually an external request for the ldap directory.

[kesselb]

/backport to stable27