From e02ef921a3588398f066096b084cca29905a7ec1 Mon Sep 17 00:00:00 2001
From: Christoph Wurst <christoph@winzerhof-wurst.at>
Date: Thu, 14 Mar 2024 10:32:21 +0100
Subject: [PATCH] perf: Load poll options max timestamps eagerly

Signed-off-by: Christoph Wurst <christoph@winzerhof-wurst.at>
---
 lib/Db/OptionMapper.php     | 22 ++++++++++++++++++++++
 lib/Service/PollService.php | 12 ++++++++----
 2 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/lib/Db/OptionMapper.php b/lib/Db/OptionMapper.php
index 2eed7e178..8a0c85906 100644
--- a/lib/Db/OptionMapper.php
+++ b/lib/Db/OptionMapper.php
@@ -28,6 +28,7 @@
 use OCP\AppFramework\Db\QBMapper;
 use OCP\DB\QueryBuilder\IQueryBuilder;
 use OCP\IDBConnection;
+use function array_chunk;
 
 /**
  * @template-extends QBMapper<Option>
@@ -162,6 +163,27 @@ public function deleteByPoll(int $pollId): void {
 		$qb->executeStatement();
 	}
 
+	public function findMaxTimestamps(array $pollIds): array {
+		$qb = $this->db->getQueryBuilder();
+		$qb->select('poll_id')
+			->selectAlias($qb->func()->max('timestamp'), 'max')
+			->from($this->getTableName())
+			->groupBy('poll_id')
+			->where($qb->expr()->in('poll_id', $qb->createParameter('ids')), IQueryBuilder::PARAM_INT_ARRAY);
+		$maxs = [];
+
+		foreach (array_chunk($pollIds, 1000) as $ids) {
+			$qb->setParameter('ids', $ids, IQueryBuilder::PARAM_INT_ARRAY);
+			$result = $qb->executeQuery();
+			while ($row = $result->fetch()) {
+				$maxs[$row['poll_id']] = $row['max'];
+			}
+			$result->closeCursor();
+		}
+
+		return $maxs;
+	}
+
 	/**
 	 * @return (int|mixed)[]
 	 *
diff --git a/lib/Service/PollService.php b/lib/Service/PollService.php
index ffd1f491b..a928c6de2 100644
--- a/lib/Service/PollService.php
+++ b/lib/Service/PollService.php
@@ -52,10 +52,11 @@
 use OCP\IUserManager;
 use OCP\IUserSession;
 use OCP\Search\ISearchQuery;
+use function array_map;
 
 class PollService {
 	private string $userId;
-	
+
 	public function __construct(
 		private Acl $acl,
 		private AppSettings $appSettings,
@@ -82,7 +83,10 @@ public function list(): array {
 		$pollList = [];
 		try {
 			$polls = $this->pollMapper->findForMe($this->userId);
-			
+			$maxTimestamps = $this->optionMapper->findMaxTimestamps(array_map(function(Poll $poll) {
+				return $poll->getId();
+			}, $polls));
+
 			foreach ($polls as $poll) {
 				try {
 					$this->acl->setPoll($poll);
@@ -91,9 +95,9 @@ public function list(): array {
 						$poll->getCreated(),
 						$poll->getLastInteraction(),
 						$poll->getExpire(),
-						$this->optionMapper->findDateBoundaries($poll->getId())['max'],
+						$maxTimestamps[$poll->getId()],
 					) + ($this->preferences->getRelevantOffsetTimestamp());
-						
+
 					// mix poll settings, acl and relevantThreshold into one array
 					$pollList[] = (object) array_merge(
 						(array) json_decode(json_encode($poll)),