res_stream_threshold_ is too high, causing incomplete data transmission

[rmclassic]

Using single header library, when sending bigger text payloads to the clients, the connection is sometimes closed before the transmit is completed.

  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
 42  606k   42  255k    0     0   255k      0  0:00:02 --:--:--  0:00:02  442k
curl: (18) transfer closed with 358690 bytes remaining to read

[The-EDev]

Could you please test this with 1MiB or more data?

[rmclassic]

I tried to reproduce the problem with string payload and did not succeed. turned out it happens with invalid data in json::wvalue object, then the server closes the connection with return code 200 instead of returning 500

[The-EDev]

Could you elaborate on what kind of invalid data you're passing to json::wvalue, since normally you would get a compiler error for that..

[rmclassic]

I thought it's because i assigned a char[12] to a std::string and then jsonified it. but the problem still persists. now i am just jsonifying int, double, and other numeric types.

[The-EDev]

hmmm, the issue doesn't happen when I do the same.. Which version of Crow are you running?

[rmclassic]

I'm using Crow/0.3
Does crow change it's behavior depending on response payload size?
because even if i concatenate the stringified JSON with another big random string, it works perfectly
even for payloads around 6MB

[rmclassic]

Found the issue, the res_stream_threshold_ is set to 1MB, and is too much, so the payload is not completed. i can lower the res_stream_threshold_ to a lower value until the library is fixed
Thanks

[The-EDev]

I was going to suggest that (hence the "Could you please test this with 1MiB or more data?"), I'm glad you found it, I'll add an app option to lower it.