[media-types] Feedback on a potential media type for upload chunks

[Marius Kleidl <[e-mail]>]

Dear working group,

in the HTTP working group, we are discussing a draft for resumable uploads
over HTTP (
https://datatracker.ietf.org/doc/draft-ietf-httpbis-resumable-upload/).
Essentially, for each file that should be uploaded, a new upload resource
is created on the server. The client can then append data to this upload
resource by sending a PATCH request. If the transfer gets interrupted, the
client can query the upload resource's current offset and then resume the
upload by appending the remaining data using another PATCH request.

As required by RFC 5789, PATCH requests must include a media type to
describe the message content. In the case of resumable uploads, the content
is just a partial chunk from the file to be uploaded without any additional
data included in the message content (no offset or length value). This
chunk might be textual or binary depending on the file that should be
uploaded (e.g. text file or video).

I didn't find a registered media type in the standards tree which matches
those semantics. However, the vendor tree includes
application/vnd.adobe.partial-upload (
https://www.iana.org/assignments/media-types/application/vnd.adobe.partial-upload),
which was registered by Adobe in 2009 for uploads in their web
applications. Its intention seems to align with the content included in
PATCH requests for resumable uploads.

Therefore, I am thinking about a standardized media type to describe
partial chunks from an upload, such as application/partial-upload or
application/upload-chunk and would love any feedback on that idea.

Best regards
Marius Kleidl