feat(ObjectStore): Make S3 MultipartUpload concurrency configurable

Signed-off-by: Ferdinand Thiessen <opensource@fthiessen.de>

lib/private/Files/ObjectStore/S3ConfigTrait.php

@@ -31,6 +31,9 @@ trait S3ConfigTrait {
 
 	protected string $bucket;
 
+	/** Maximum number of concurrent multipart uploads */
+	protected int $concurrency;
+
 	protected int $timeout;
 
 	protected string $proxy;

lib/private/Files/ObjectStore/S3ConnectionTrait.php

@@ -48,10 +48,10 @@ trait S3ConnectionTrait {
 
 	protected string $id;
 
-	protected ?S3Client $connection;
-
 	protected bool $test;
 
+	protected ?S3Client $connection = null;
+
 	protected function parseParams($params) {
 		if (empty($params['bucket'])) {
 			throw new \Exception("Bucket has to be configured.");
@@ -61,6 +61,8 @@ protected function parseParams($params) {
 
 		$this->test = isset($params['test']);
 		$this->bucket = $params['bucket'];
+		// Default to 5 like the S3 SDK does
+		$this->concurrency = $params['concurrency'] ?? 5;
 		$this->proxy = $params['proxy'] ?? false;
 		$this->timeout = $params['timeout'] ?? 15;
 		$this->storageClass = !empty($params['storageClass']) ? $params['storageClass'] : 'STANDARD';
@@ -92,7 +94,7 @@ public function getProxy() {
 	 * @throws \Exception if connection could not be made
 	 */
 	public function getConnection() {
-		if (!is_null($this->connection)) {
+		if ($this->connection !== null) {
 			return $this->connection;
 		}
 

lib/private/Files/ObjectStore/S3ObjectTrait.php

@@ -129,6 +129,7 @@ protected function writeSingle(string $urn, StreamInterface $stream, string $mim
 	protected function writeMultiPart(string $urn, StreamInterface $stream, string $mimetype = null): void {
 		$uploader = new MultipartUploader($this->getConnection(), $stream, [
 			'bucket' => $this->bucket,
+			'concurrency' => $this->concurrency,
 			'key' => $urn,
 			'part_size' => $this->uploadPartSize,
 			'params' => [