Feature request: cleanup unfinished or broken uploads

[ivandeex]

Hi @lukechampine

Recently we started development of the Sia backend for rclone, a cloud storage mounting and manipulation utility. Rclone talks with siad via API, e.g. uploads files using the streaming API endpoint.

We have pretty thorough test suite for backends. One of unit tests simulates an upload failing in the middle then verifies that backend has captured the error and deleted incomplete file. Unfortunately siad provides no way to signal such failure. Moreover, if I wanted to have rclone remove the zombie, I'd have to wait because Sia workers running behind siad will finalize the upload a few moments later (depending on the file size) after rclone has finished talking to siad.

I discussed the issue with @MSevey on discord, and he noted:

For skyd we actually have resumable uploads and we are implementing a concept of unfinished files.

@lukechampine
I guess that siad could either introduce a kind of cancel-last-upload API call or a concept of unfinished files like skyd. Any ideas?