limit constructing of result objects in file search

even thought we currently have no proper way of limiting the search itself, we can at least limit the construction of the result objects.

this saves about 40% of the time spend in the search request in my local testing

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

lib/private/Search/Provider/File.php

@@ -29,20 +29,31 @@
 namespace OC\Search\Provider;
 
 use OC\Files\Filesystem;
+use OCP\Search\PagedProvider;
 
 /**
  * Provide search results from the 'files' app
  */
-class File extends \OCP\Search\Provider {
+class File extends PagedProvider {
 
 	/**
 	 * Search for files and folders matching the given query
+	 *
 	 * @param string $query
-	 * @return \OCP\Search\Result
+	 * @param int|null $limit
+	 * @param int|null $offset
+	 * @return \OCP\Search\Result[]
 	 */
-	public function search($query) {
+	public function search($query, int $limit = null, int $offset = null) {
+		if ($offset === null) {
+			$offset = 0;
+		}
+		\OC_Util::setupFS();
 		$files = Filesystem::search($query);
 		$results = [];
+		if ($limit !== null) {
+			$files = array_slice($files, $offset, $offset + $limit);
+		}
 		// edit results
 		foreach ($files as $fileData) {
 			// skip versions
@@ -75,4 +86,12 @@ public function search($query) {
 		// return
 		return $results;
 	}
+
+	public function searchPaged($query, $page, $size) {
+		if ($size === 0) {
+			return $this->search($query);
+		} else {
+			return $this->search($query, $size, ($page - 1) * $size);
+		}
+	}
 }