multiple simultaneous uploads of the same file

[zooko]

As described in #950 (upload doesn't appear in the Recent Uploads Downloads page) and #951 (uploads aren't cancelled by closing the web page) I started an upload of a large (350 MB) file, then started a second upload of the same file. Later I discovered that both uploads were running:

# 2010-02-14 18:38:58.761541Z [152794]: <Encoder for 5ossh> uploaded 266352528 / 353388984 bytes (75%) of your file.
# 2010-02-14 18:39:06.215643Z [152863]: storage: allocate_buckets 5osshw7oonef6qlpvdvtmuskt4
# 2010-02-14 18:39:17.599753Z [152865]: <Encoder for 5ossh> uploaded 266483607 / 353388984 bytes (75%) of your file.
# 2010-02-14 18:39:17.608450Z [152867]: peer selection successful for <Tahoe2PeerSelector for upload 5ossh>: placed all 26 shares, sent 23 queries to 13 peers, 20 queries placed some shares, 2 placed none, got 1 errors
# 2010-02-14 18:39:17.610185Z [152868]: _send_shares, used_peers is set([<PeerTracker for peer we543qo4 and SI 5ossh>, <PeerTracker for peer hfhjhv7s and SI 5ossh>, <PeerTracker for peer 2bu4lxwa and SI 5ossh>, <PeerTracker for peer xjy2clbq and SI 5ossh>, <PeerTracker for peer 5ouv6kib and SI 5ossh>, <PeerTracker for peer t6d76eso and SI 5ossh>, <PeerTracker for peer rhug4hsl and SI 5ossh>, <PeerTracker for peer wbxexhfu and SI 5ossh>, <PeerTracker for peer 62u7qrne and SI 5ossh>, <PeerTracker for peer 5xzrcb27 and SI 5ossh>])
# 2010-02-14 18:39:17.887869Z [152869]: <Encoder for 5ossh> starting
# 2010-02-14 18:39:18.554996Z [152947]: <Encoder for 5ossh> uploaded 266614686 / 353388984 bytes (75%) of your file.
# 2010-02-14 18:39:18.597406Z [153004]: <Encoder for 5ossh> uploaded 131079 / 353388984 bytes (0%) of your file.
# 2010-02-14 18:39:21.569559Z [153081]: <Encoder for 5ossh> uploaded 266745765 / 353388984 bytes (75%) of your file.
# 2010-02-14 18:39:21.610486Z [153138]: <Encoder for 5ossh> uploaded 262158 / 353388984 bytes (0%) of your file.

To close this ticket, make so a second upload of the same file (when using the same added convergence secret of course) just waits for the first upload instead of starting a second task (which will compete with the first one for resources).

[zooko]

This is related to #1032 (Display active HTTP upload operations on the status page), #951 (uploads aren't cancelled by closing the web page) and #320 (add streaming (on-line) upload to HTTP interface).

[zooko]

It was impulsive of me to put this ticket into the 1.8 Milestone. We have enough other important issues in front of us.

[daira]

Merging into #2409.