Upload stall timeout detection not accurate

[PVince81]

Steps

1. occ config:app:set files max_chunk_size --value 1024
2. occ config:app:set files upload_stall_timeout --value 3
3. Set web server to sleep for one minute randomly during chunk upload, see code below
4. Upload a 10Kb file (10 chunks)

Code to make server randomly delay, edit "apps/dav/lib/Connector/Sabre/Directory.php" and replace createFileDirectly with the code below:

        public function createFileDirectly($name, $data) {
                $tgt = $this->fileView->fopen($this->getPath() . '/' .  $name, 'wb');

                $count = 0;
                while(!feof($data)) {
                        if (mt_rand(0,99) <= 10) {
                                sleep(60);
                        }
                        $count = fwrite($tgt, fread($data, 512));
                }
                fclose($data);
                fclose($tgt);
        }

Expected result

Stall timeout detected after 3 seconds, then chunk is retried.
Stall timeout must not be tied to progress bar.

Actual result

Stall timeout detected after 1 minute, which is when the server resumes sending data after the sleep() and moves the progress bar.

Versions

OC 10.0.9 + patch from #32170

@pmaier1 FYI

@butonic not sure why you originally decided to tie the stall timeout to the progress bar event. It doesn't seem to work on some environments where the server stalls forever and never sends any bytes, so the progress bar never moves and the stall timeout is never detected or detected very late when the user already gave up.

[PVince81]

hmm now I see there is code to update the progress bar every second or so... will debug

[PVince81]

ok, got it: the first time a chunk stalls, it resumes correctly after 3 seconds.
but the second chunk waits forever. something isn't resetting itself properly...

[PVince81]

bahhhhh, it detects the stall repeatedly but the "retry" routine doesn't seem to be able to run again a second time

[PVince81]

PR here: #32283

[PVince81]

here's another version of the hack to make it sleep only once per chunk, but also decide upfront whether to block that chunk or not:

        public function createFileDirectly($name, $data) {
                $tgt = $this->fileView->fopen($this->getPath() . '/' .  $name, 'wb');

                // decide whether to sleep for this chunk
                $willSimulateSleep = mt_rand(0,99) <= 10;

                $count = 0;
                while(!feof($data)) {
                        if (mt_rand(0,99) <= 10 && $willSimulateSleep) {
                                sleep(120);
                                $willSimulateSleep = false;
                        }
                        $count = fwrite($tgt, fread($data, 512));
                }
                fclose($data);
                fclose($tgt);
        }

[DeepDiver1975]

reopening because of open comment in PR: #32283 (comment)