use efficient tag retrieval on DAV report request

- uses DAV search approach against valid files joined by systemtag selector
- reduced table join for tag/systemtag search
- supports pagination
- no changes to the output formats or similar

Example request body:

<?xml version="1.0"?>
<oc:filter-files xmlns:d="DAV:" xmlns:oc="http://owncloud.org/ns" xmlns:nc="http://nextcloud.org/ns" xmlns:ocs="http://open-collaboration-services.org/ns">
  <d:prop>
    <d:getcontentlength/>
    <d:getcontenttype/>
    <d:getetag/>
    <d:getlastmodified/>
    <d:resourcetype/>
    <nc:face-detections/>
    <nc:file-metadata-size/>
    <nc:has-preview/>
    <nc:realpath/>
    <oc:favorite/>
    <oc:fileid/>
    <oc:permissions/>
    <nc:nbItems/>
  </d:prop>
  <oc:filter-rules>
    <oc:systemtag>32</oc:systemtag>
  </oc:filter-rules>
  <d:limit>
    <d:nresults>50</d:nresults>
    <nc:firstresult>0</nc:firstresult>
  </d:limit>
</oc:filter-files>

Signed-off-by: Arthur Schiwon <blizzz@arthur-schiwon.de>

3 files changed, 28 insertions, 17 deletions

diff --git a/lib/private/Files/Cache/QuerySearchHelper.php b/lib/private/Files/Cache/QuerySearchHelper.php
index 75e203d5fd9..ea763a76846 100644
--- a/lib/private/Files/Cache/QuerySearchHelper.php
+++ b/lib/private/Files/Cache/QuerySearchHelper.php
@@ -36,6 +36,7 @@ use OCP\Files\IMimeTypeLoader;
 use OCP\Files\IRootFolder;
 use OCP\Files\Mount\IMountPoint;
 use OCP\Files\Search\ISearchBinaryOperator;
+use OCP\Files\Search\ISearchComparison;
 use OCP\Files\Search\ISearchQuery;
 use OCP\IDBConnection;
 use Psr\Log\LoggerInterface;
@@ -151,22 +152,26 @@ class QuerySearchHelper {
 			if ($user === null) {
 				throw new \InvalidArgumentException("Searching by tag requires the user to be set in the query");
 			}
-			$query
-				->leftJoin('file', 'vcategory_to_object', 'tagmap', $builder->expr()->eq('file.fileid', 'tagmap.objid'))
-				->leftJoin('tagmap', 'vcategory', 'tag', $builder->expr()->andX(
-					$builder->expr()->eq('tagmap.type', 'tag.type'),
-					$builder->expr()->eq('tagmap.categoryid', 'tag.id'),
-					$builder->expr()->eq('tag.type', $builder->createNamedParameter('files')),
-					$builder->expr()->eq('tag.uid', $builder->createNamedParameter($user->getUID()))
-				))
-				->leftJoin('file', 'systemtag_object_mapping', 'systemtagmap', $builder->expr()->andX(
-					$builder->expr()->eq('file.fileid', $builder->expr()->castColumn('systemtagmap.objectid', IQueryBuilder::PARAM_INT)),
-					$builder->expr()->eq('systemtagmap.objecttype', $builder->createNamedParameter('files'))
-				))
-				->leftJoin('systemtagmap', 'systemtag', 'systemtag', $builder->expr()->andX(
-					$builder->expr()->eq('systemtag.id', 'systemtagmap.systemtagid'),
-					$builder->expr()->eq('systemtag.visibility', $builder->createNamedParameter(true))
-				));
+			if ($searchQuery->getSearchOperation() instanceof ISearchComparison && $searchQuery->getSearchOperation()->getField() === 'systemtag') {
+				$query
+					->leftJoin('file', 'systemtag_object_mapping', 'systemtagmap', $builder->expr()->andX(
+						$builder->expr()->eq('file.fileid', $builder->expr()->castColumn('systemtagmap.objectid', IQueryBuilder::PARAM_INT)),
+						$builder->expr()->eq('systemtagmap.objecttype', $builder->createNamedParameter('files'))
+					))
+					->leftJoin('systemtagmap', 'systemtag', 'systemtag', $builder->expr()->andX(
+						$builder->expr()->eq('systemtag.id', 'systemtagmap.systemtagid'),
+						$builder->expr()->eq('systemtag.visibility', $builder->createNamedParameter(true))
+					));
+			} else {
+				$query
+					->leftJoin('file', 'vcategory_to_object', 'tagmap', $builder->expr()->eq('file.fileid', 'tagmap.objid'))
+					->leftJoin('tagmap', 'vcategory', 'tag', $builder->expr()->andX(
+						$builder->expr()->eq('tagmap.type', 'tag.type'),
+						$builder->expr()->eq('tagmap.categoryid', 'tag.id'),
+						$builder->expr()->eq('tag.type', $builder->createNamedParameter('files')),
+						$builder->expr()->eq('tag.uid', $builder->createNamedParameter($user->getUID()))
+					));
+			}
 		}
 
 		$this->applySearchConstraints($query, $searchQuery, $caches);
diff --git a/lib/private/Files/Node/Folder.php b/lib/private/Files/Node/Folder.php
index 38a7645631c..862b8e8ad64 100644
--- a/lib/private/Files/Node/Folder.php
+++ b/lib/private/Files/Node/Folder.php
@@ -296,7 +296,12 @@ class Folder extends Node implements \OCP\Files\Folder {
 	 * @return Node[]
 	 */
 	public function searchByTag($tag, $userId) {
-		$query = $this->queryFromOperator(new SearchComparison(ISearchComparison::COMPARE_EQUAL, 'tagname', $tag), $userId);
+		$query = $this->queryFromOperator(new SearchComparison(ISearchComparison::COMPARE_EQUAL, 'tag', $tag), $userId);
+		return $this->search($query);
+	}
+
+	public function searchBySystemTag(string $tag, string $userId, int $limit = 0, int $offset = 0): array {
+		$query = $this->queryFromOperator(new SearchComparison(ISearchComparison::COMPARE_EQUAL, 'systemtag', $tag), $userId, $limit, $offset);
 		return $this->search($query);
 	}
 
diff --git a/lib/private/SystemTag/SystemTagObjectMapper.php b/lib/private/SystemTag/SystemTagObjectMapper.php
index b61a81a1fa7..864ba3e91a8 100644
--- a/lib/private/SystemTag/SystemTagObjectMapper.php
+++ b/lib/private/SystemTag/SystemTagObjectMapper.php
@@ -135,6 +135,7 @@ class SystemTagObjectMapper implements ISystemTagObjectMapper {
 		while ($row = $result->fetch()) {
 			$objectIds[] = $row['objectid'];
 		}
+		$result->closeCursor();
 
 		return $objectIds;
 	}