When you've not started to download any of a file, or when you've only downloaded some, do you still give a search query answer to who searches for those files?
wouldn't this be a way to get more sources.... from who's searching for a file you're already downloading?
how about "try-once" sources that are added from who's searching for the file... since they might be downloading it now and can show you more sources.
for when a download gets stuck with no sources, but i hope it finds sources after a while but usually doesn't.
but wouldn't you catch yourself into a new mesh of sources if you found who's searching for what you're downloading is downloading too?
maybe especially URN search query's or absolute filename search queries would be more sure to try using the searcher as a source?
then while downloading files and some are stopped, who's searching for them can lead you to a source mesh to download more?
when you'r downloading a file but got none of the file, do you still give a search response for the file? can't you get more sources if you do and they try to download from you, but you say you have none of the file, but they do, and now \they're a source?
do you get sources from who tries to download from you, and they know more sources?