[Cppcms-users] Check space left on device before file upload

[Julian P. <ju...@wh...>]

Hallo,

on some of our embedded platforms a problem occurred that seems related
to the fact, that libcppcms doesn't seem to check the available space in
the location for uploaded files before it accepts an upload from the
browser, resulting in incomplete files (libcppcms seems to throw away
anything it can't write anymore). Nevertheless, there is no feedback
given to our code that something went wrong during upload and our code
can't show any specific error to the user because it doesn't know that
there had been a problem during upload.

In my opinion, libcppcms should do one (or maybe both) of these two
things to help application code to display detailed error messages to
the user:
1) Check available disk space after client sent Content-Length header,
decide whether to accept the request or not
2) Notify the application code, that upload failed because of too less
disk space (maybe one could do this via the existing infrastructure of
invoking validate() on the upload form field's widget instance and
adding another method that would return any occurred errors)

Best regards,
Julian