Complete the getter-based transformation, by hiding ".uri" and updating
callers to use get_uri(). Also don't set a dummy self._uri, leave it
undefined until someone calls set_uri().
This fixes a test failure found against current Twisted trunk in
test_mutable.Filenode.test_retrieve_producer_mdmf (when it uses
PausingAndStoppingConsumer). There must be some sort of race: I could
make it fail against Twisted-11.0 if I just increased the 0.5s delay in
test_download.PausingAndStoppingConsumer to about 0.6s, and could make
Twisted-trunk pass by reducing it to about 0.3s .
I fixed the test (as opposed to the bug) by replacing the delay with a
simple reliable eventually(), and adding extra asserts to fail the test
if the consumer's write() method is called while the producer is
supposed to be paused
The bug itself was that mutable.retrieve.Retrieve wasn't checking the
"stopped" flag after resuming from a pause, and thus delivered one
segment to a consumer that wasn't expecting it. I split out
stopped-flag-checking to separate function, which is now called
immediately after _check_for_paused(). I also cleaned up some Deferred
usage and whitespace.
This patch was originally written by Brian, but was re-recorded by Zooko to use
darcs replace instead of hunks for any file in which it would result in fewer
total hunks.
refs #1363
Pass around IServer instance instead of (peerid, rref) tuple. Replace
"descriptor" with "server". Other replacements:
get_all_servers -> get_connected_servers/get_known_servers
get_servers_for_index -> get_servers_for_psi (now returns IServers)
This change still needs to be pushed further down: lots of code is now
getting the IServer and then distributing (peerid, rref) internally.
Instead, it ought to distribute the IServer internally and delay
extracting a serverid or rref until the last moment.
no_network.py was updated to retain parallelism.
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.
The lost-progress bug occurred when two simultanous read() calls fetched
different segments, and the first one failed (due to corruption, or the other
bugs in #1154): the second read() would never complete. While in this state,
cancelling the second read by having its consumer call stopProducing) would
trigger the cancel-intolerance bug. Finally, in downloader.node.Cancel,
prevent late cancels by adding an 'active' flag
The Range header causes n.read() to be called with an offset= of type 'long',
which eventually got used in a Spans/DataSpans object's __len__ method.
Apparently python doesn't permit __len__() to return longs, only ints.
Rewrote Spans/DataSpans to use s.len() instead of len(s) aka s.__len__() .
Added a test in test_download. Note that test_web didn't catch this because
it uses mock FileNodes for speed: it's probably time to rewrite that.
There is still an unresolved error-recovery problem in #1154, so I'm not
closing the ticket quite yet.
* remove Downloader.download_to_data/download_to_filename/download_to_filehandle
* remove download.Data/FileName/FileHandle targets
* remove filenode.download/download_to_data/download_to_filename methods
* leave Downloader.download (the whole Downloader will go away eventually)
* add util.consumer.MemoryConsumer/download_to_data, for convenience
(this is mostly used by unit tests, but it gets used by enough non-test
code to warrant putting it in allmydata.util)
* update tests
* removes about 180 lines of code. Yay negative code days!
Overall plan is to rewrite immutable/download.py and leave filenode.read() as
the sole read-side API.
