some cleanup and documentation

Signed-off-by: Robin Appelman <robin@icewind.nl>

Author: icewind1991

lib/private/Files/Cache/QuerySearchHelper.php

@@ -256,6 +256,11 @@ protected function getQueryBuilder() {
 	}
 
 	/**
+	 * Perform a file system search in multiple caches
+	 *
+	 * the results will be grouped by the same array keys as the $caches argument to allow
+	 * post-processing based on which cache the result came from
+	 *
 	 * @template T of array-key
 	 * @param ISearchQuery $searchQuery
 	 * @param array<T, ICache> $caches
@@ -305,10 +310,6 @@ public function searchInCaches(ISearchQuery $searchQuery, array $caches): array
 		}, $caches));
 		$query->andWhere($this->searchOperatorToDBExpr($builder, new SearchBinaryOperator(ISearchBinaryOperator::OPERATOR_OR, $storageFilters)));
 
-		if ($searchQuery->limitToHome() && ($this instanceof HomeCache)) {
-			$query->andWhere($builder->expr()->like('path', $query->expr()->literal('files/%')));
-		}
-
 		$this->addSearchOrdersToQuery($query, $searchQuery->getOrder());
 
 		if ($searchQuery->getLimit()) {
@@ -328,6 +329,7 @@ public function searchInCaches(ISearchQuery $searchQuery, array $caches): array
 		$result->closeCursor();
 
 		// loop trough all caches for each result to see if the result matches that storage
+		// results are grouped by the same array keys as the caches argument to allow the caller to distringuish the source of the results
 		$results = array_fill_keys(array_keys($caches), []);
 		foreach ($rawEntries as $rawEntry) {
 			foreach ($caches as $cacheKey => $cache) {

lib/private/Files/Node/Folder.php

@@ -235,18 +235,8 @@ public function search($query) {
 			$query = $this->queryFromOperator(new SearchComparison(ISearchComparison::COMPARE_LIKE, 'name', '%' . $query . '%'));
 		}
 
-		// Limit+offset for queries with ordering
-		//
-		// Because we currently can't do ordering between the results from different storages in sql
-		// The only way to do ordering is requesting the $limit number of entries from all storages
-		// sorting them and returning the first $limit entries.
-		//
-		// For offset we have the same problem, we don't know how many entries from each storage should be skipped
-		// by a given $offset, so instead we query $offset + $limit from each storage and return entries $offset..($offset+$limit)
-		// after merging and sorting them.
-		//
-		// This is suboptimal but because limit and offset tend to be fairly small in real world use cases it should
-		// still be significantly better than disabling paging altogether
+		// search is handled by a single query covering all caches that this folder contains
+		// this is done by collect
 
 		$limitToHome = $query->limitToHome();
 		if ($limitToHome && count(explode('/', $this->path)) !== 3) {
@@ -258,11 +248,11 @@ public function search($query) {
 		$storage = $mount->getStorage();
 		$internalPath = $mount->getInternalPath($this->path);
 
-		$caches = ['' => new CacheJail($storage->getCache(''), $internalPath)];
-		/** @var array{IMountPoint, string}[] $infoParams */
-		$infoParams = [
-			'' => [$mount, '']
-		];
+		// collect all caches for this folder, indexed by their mountpoint relative to this folder
+		// and save the mount which is needed later to construct the FileInfo objects
+
+		$caches = ['' => new CacheJail($storage->getCache(''), $internalPath)]; // a temporary CacheJail is used to handle filtering down the results to within this folder
+		$mountByMountPoint = ['' => $mount];
 
 		if (!$limitToHome) {
 			$mounts = $this->root->getMountsIn($this->path);
@@ -271,18 +261,20 @@ public function search($query) {
 				if ($storage) {
 					$relativeMountPoint = ltrim(substr($mount->getMountPoint(), $rootLength), '/');
 					$caches[$relativeMountPoint] = $storage->getCache('');
-					$infoParams[$relativeMountPoint] = [$mount, ''];
+					$mountByMountPoint[$relativeMountPoint] = $mount;
 				}
 			}
 		}
 
 		/** @var QuerySearchHelper $searchHelper */
 		$searchHelper = \OC::$server->get(QuerySearchHelper::class);
 		$resultsPerCache = $searchHelper->searchInCaches($query, $caches);
-		$files = array_merge(...array_map(function(array $results, $relativeMountPoint) use ($infoParams) {
-			$params = $infoParams[$relativeMountPoint];
-			return array_map(function(ICacheEntry $result) use ($relativeMountPoint, $params) {
-				return $this->cacheEntryToFileInfo($params[0], $relativeMountPoint, $params[1], $result);
+
+		// loop trough all results per-cache, constructing the FileInfo object from the CacheEntry and merge them all
+		$files = array_merge(...array_map(function(array $results, $relativeMountPoint) use ($mountByMountPoint) {
+			$mount = $mountByMountPoint[$relativeMountPoint];
+			return array_map(function(ICacheEntry $result) use ($relativeMountPoint, $mount) {
+				return $this->cacheEntryToFileInfo($mount, $relativeMountPoint, $result);
 			}, $results);
 		}, array_values($resultsPerCache), array_keys($resultsPerCache)));
 
@@ -291,10 +283,9 @@ public function search($query) {
 		}, $files);
 	}
 
-	private function cacheEntryToFileInfo(IMountPoint $mount, string $appendRoot, string $trimRoot, ICacheEntry $cacheEntry): FileInfo {
-		$trimLength = strlen($trimRoot);
+	private function cacheEntryToFileInfo(IMountPoint $mount, string $appendRoot, ICacheEntry $cacheEntry): FileInfo {
 		$cacheEntry['internalPath'] = $cacheEntry['path'];
-		$cacheEntry['path'] = $appendRoot . substr($cacheEntry['path'], $trimLength);
+		$cacheEntry['path'] = $appendRoot . $cacheEntry->getPath();
 		return new \OC\Files\FileInfo($this->path . '/' . $cacheEntry['path'], $mount->getStorage(), $cacheEntry['internalPath'], $cacheEntry, $mount);
 	}