OpenStack SWIFT: fseek(): stream does not support seeking

[solracsf]

Duplicate of #8275 or #14617 but for OpenStack SWIFT, as #20033 does NOT fix it (it is intended for S3 only).

[PHP] Error: Error: fseek(): stream does not support seeking at /public/3rdparty/icewind/streams/src/Wrapper.php#82 at <<closure>>

 0. <<closure>>
    OC\Log\ErrorHandler::onError(2, "fseek(): stream ... g", "/srv/users/ ... p", 82, {offset: 32768,whence: 0})
 1. /public/3rdparty/icewind/streams/src/Wrapper.php line 82
    fseek(null, 32768, 0)
 2. <<closure>>
    Icewind\Streams\Wrapper->stream_seek(32768, 0)
 3. /public/3rdparty/icewind/streams/src/Wrapper.php line 82
    fseek(null, 32768, 0)
 4. <<closure>>
    Icewind\Streams\Wrapper->stream_seek(32768, 0)
 5. /public/3rdparty/sabre/dav/lib/DAV/CorePlugin.php line 184
    fseek(null, 32768, 0)
 6. /public/3rdparty/sabre/event/lib/WildcardEmitterTrait.php line 89
    Sabre\DAV\CorePlugin->httpGet(Sabre\HTTP\Request {}, Sabre\HTTP\Response {})
 7. /public/3rdparty/sabre/dav/lib/DAV/Server.php line 474
    Sabre\DAV\Server->emit("method:GET", [Sabre\HTTP\Requ ... }])
 8. /public/3rdparty/sabre/dav/lib/DAV/Server.php line 251
    Sabre\DAV\Server->invokeMethod(Sabre\HTTP\Request {}, Sabre\HTTP\Response {})
 9. /public/3rdparty/sabre/dav/lib/DAV/Server.php line 319
    Sabre\DAV\Server->start()
10. /public/apps/dav/lib/Server.php line 332
    Sabre\DAV\Server->exec()
11. /public/apps/dav/appinfo/v2/remote.php line 35
    OCA\DAV\Server->exec()
12. /public/remote.php line 167
    require_once("/srv/users/ ... p")

GET /remote.php/dav/files/user/Videos/40590592_2138161566405349_5883589116544679936_n.mp4

[vpecinka]

Same issue here...

[vpecinka]

My traceback says also a problem arised in nextcloud/3rdparty/sabre/dav/lib/DAV/CorePlugin.php:184

The code says

            // Streams may advertise themselves as seekable, but still not
            // actually allow fseek.  We'll manually go forward in the stream
            // if fseek failed.
            if (!stream_get_meta_data($body)['seekable'] || -1 === fseek($body, $start, SEEK_SET)) {
                $consumeBlock = 8192;
                for ($consumed = 0; $start - $consumed > 0;) {
                    if (feof($body)) {
                        throw new Exception\RequestedRangeNotSatisfiable('The start offset ('.$start.') exceeded the size of the entity ('.$consumed.')');
                    }
                    $consumed += strlen(fread($body, min($start - $consumed, $consumeBlock)));
                }
            }

however as seen the stream_seek() is called via wrapper nextcloud/3rdparty/icewind/streams/src/Wrapper.php:82

        public function stream_seek($offset, $whence = SEEK_SET) {
                $result = fseek($this->source, $offset, $whence);
                return $result == 0 ? true : false;
        }

that returns false or true (not -1)

[vpecinka]

Ok, i discovered there is Icewind\Streams\SeekableWrapper , replacing it in the Swift.php seems working

--- lib/private/Files/ObjectStore/Swift.php.orig	2021-02-24 20:07:09.000000000 +0100
+++ lib/private/Files/ObjectStore/Swift.php	2021-03-17 17:27:04.987925583 +0100
@@ -29,12 +29,13 @@
 use GuzzleHttp\Client;
 use GuzzleHttp\Exception\BadResponseException;
 use function GuzzleHttp\Psr7\stream_for;
-use Icewind\Streams\RetryWrapper;
+use Icewind\Streams\SeekableWrapper;
 use OCP\Files\NotFoundException;
 use OCP\Files\ObjectStore\IObjectStore;
 use OCP\Files\StorageAuthException;
 
-const SWIFT_SEGMENT_SIZE = 1073741824; // 1GB
+
+const SWIFT_SEGMENT_SIZE = 209715200;
 
 class Swift implements IObjectStore {
 	/**
@@ -126,7 +127,7 @@
 			}
 		}
 
-		return RetryWrapper::wrap($response->getBody()->detach());
+		return SeekableWrapper::wrap($response->getBody()->detach());
 	}
 
 	/**

Can anybody confirm?

[solracsf]

I can try it next week.
cc @icewind1991 if you can give us your opinion before submit any PR.

[vpecinka]

Still, I think the approach as in #20033 is better, as Swift supports Range: bytes=.... The SeekableWrapper seems always reading only forwards, not backwards.

[AndyXheli]

Still an issue on NC 20.0.8

[szaimen]

I suppose this is still valid on NC21.0.3?

This issue has been automatically marked as stale because it has not had recent activity and seems to be missing some essential information. It will be closed if no further activity occurs. Thank you for your contributions.

[AndyXheli]

Still an issue