I don’t think implementing multi-sourcing on OpenNap is difficult…
On server side, already has a partial download command as "resume" and stores MD5 as a file identifier "signature".
Add straight MD5 search. This will help finding exact matching files. WinMX's "Find Alternate..." is search by file name and filtered by MD5. Matching is done at client side, MX will not find the exact file with wrong name.
On client side, current MD5 hash is first 300k of file, IMHO that’s not enough for "Trusted" multi-sourcing. Full hash is ideal but takes long time to prepare share list, maybe small chunk at beginning of each quarters?. And "Upload termination delay" will allow uploading client to request second part within file without losing uploading slot. Ex: client 'A' started downloading a 1000k file from user 'B' at 0, user 'C' at 500k, 500K~1000k is finished while download from user 'B' still at 100k, then client 'A' requests user 'C' the file from 250k. without termination delay, user 'C' sees second request "new", may send to the end of queue.
no?
