Permanent error should stop Flow from sending chunks.

[nuvan]

HHi guys. First let me thank you all for this awesome lib.

I don't know if I'm interpreting this right but if a permanent error arouses shouldn't the chunks stop being sent to the server (using testChunks: true)?
I've added a CRC field using the preprocess method. I'm testing the CRC sent in every chunck at server side and replying with 409 if a chunk doesn't match, while one tries to resume a file. I've also added the 409 code as a permanent error.
The behaviour I'm noticing is that flow.js keeps sending chunks independently of the configured permanent errors.

Is this a issue or a misinterpretation of the feature?

[nuvan]

Meanwhile I've looked at the code and added this around line 1140-1154 to test the behaviour and it seems to solve the issue. Now if I receive a 409 (conflict) flow stops the upload process and marks it as an error.

this.testHandler = function(event) {
  var status = $.status();
  if (status === 'success') {
    $.tested = true;
    $.fileObj.chunkEvent(status, $.message());
    $.flowObj.uploadNextChunk();
  } else if (status === 'error') {
    console.log("Irrecoverable error");
    $.fileObj.chunkEvent(status, $.message());
  } else if (!$.fileObj.paused) {// Error might be caused by file pause method
    $.tested = true;
    $.send();
  }
};

(I've closed the issue by mistake)

[AidasK]

File testing does not support permanent error handling at the moment and this should be implemented.
Your code causes to fail one test case (File testing feature is not working anymore). If you could fix this, please make a pull request.

Line which is causing problems:
https://github.com/flowjs/flow.js/blob/master/src/flow.js#L1309
maxChunkRetries by default is set to 0 and this statement is always true then file is being tested.

[nuvan]

Thanks for the reply @AidasK . I'll give it a stab this weekend.

[AidasK]

Should be fixed with c2080ef
Please test it, will be released once tested in a production.

[adiroiban]

Would be nice to also update the documentation/README to describe how this can be done. Thanks!

[adiroiban]

Do you/we want to abort on any errors?

For example 503 Service Unavailable is a transient server error and for this kind of error we would like to flow.js client to retry the test.

From this point of view, it would be nice if flow.js would allow configuring a list of error codes which has the semantic of "reject".

I would say that we would need a list of rejectErrorCode = [409] and stop testing only if this specific error code is returned... for all other errors, retry.

Thanks!

[AidasK]

We have such an option, it is called permanentErrors https://github.com/flowjs/flow.js#configuration.

Unfortunately, request retry works only for upload requests. How file testing works:

1. We send GET(by default) request to the server with chunk params
2. Server checks and validates the file:

• if file is invalid, server returns error code, which is in permanentErrors list, file upload stops.
• if file is valid and file chunk exists on the server side, server returns status from successStatuses list. Client moves to the next chunk test/upload.
• if file is valid and file chunk does not exists on the server side, server returns any status, which is not in the permanentErrors and successStatuses lists. Client uploads the chunk.

In order to support retry feature for file testing, we need a separate status list, such as chunkNotFoundStatuses. If response status is not in this array, then retry.

[adiroiban]

Many thanks! I think that copying your comment in the documentation would be a great improvement to the documentation :)