For one thing, this makes missing-dependency failures into DistributionNotFound errors instead of ImportErrors, which might be more useful to the user. For another thing, if someone is using distributions that were installed with --multi-version, then they might be not importable until after require_auto_deps() has been run. (The docs claim that this would be the case, but we don't have an example of this happening at this time.)
* repairer (really the uploader) reads beyond end of input file (Uploadable)
* new-downloader does not tolerate overreads
* uploader does lots of tiny reads (inefficient)
This fixes the last two. The uploader still does a single overread at the end
of the input file, but now that's ok so we can leave it in place. The
uploader now expects the Uploadable to behave like a normal disk
file (reading beyond EOF will return less data than was asked for), and now
the new-downloadable behaves that way.
This removes the need to use a locally-built (dependency) bin/twistd, and
removes a big chunk of behavior differences between unix and windows. It
also happens to resolve the "client node probably started" uncertainty.
Might help with #1190, #602, and #71.
fixes#530. I earlier tried this twice (see #530 for history) and then twice rolled it back due to some problems that arose. However, I didn't write down what the problems were in enough detail on the ticket that I can tell today whether those problems are still issues, so here goes the third attempt. (I did write down on the ticket that it would not create site.py or .pth files in the target directory with --multi-version mode, but I didn't explain why *that* was a problem.)
fixes#1191
Patch by Brian. This patch description was actually written by Zooko, but I forged Brian's name on the "author" field so that he would get credit for this patch in revision control history.
If you are investigating the bug in new-downloader, one way to investigate might be to change this ordering to a different fixed order (e.g. rotate by 4 instead of rotate by 5) and observe how the behavior of new-downloader differs in that case.
Kyle's OpenBSD buildslave used 41 reads when doing this test. The fact that I'm blindly bumping this number up to match the observed behavior probably means this isn't a good criterion to be testing for anyway. But perhaps someone else (Brian) could investigate why that run on Kyle's OpenBSD box took four more reads than we expected, and whether the fact that it took 41 reads to do this operation is indicative of an actual problem.
deliver all shares at once instead of feeding them out one-at-a-time.
Also fix distribution of real-number-of-segments information: now all
CommonShares (not just the ones used for the first segment) get a
correctly-sized hashtree. Previously, the late ones might not, which would
make them crash and get dropped (causing the download to fail if the initial
set were insufficient, perhaps because one of their servers went away).
Update tests, add some TODO notes, improve variable names and comments.
Improve logging: add logparents, set more appropriate levels.
