add get_available_space() to NativeStorageServer
It uses a new 'available-space' key in the server's v1 version dict, or falls
back to 'maximum-immutable-share-size' (which presently always has the same
value but could have a different meaning in the future).
This is a squash merge of 9773555bb87fab71145ad7a0e84785a4e92d11f7
Instead of constructing a sys.argv for 'twistd' that reads the node's
.tac file, we construct arguments that tell twistd to use a special
in-memory-only plugin that creates the desired node instance directly.
We still use the name of the .tac file to decide which kind of instance
to make (Client, IntroducerNode, KeyGenerator, StatsGatherer), but never
actually read the contents of the .tac file. Later improvements could
change this to look inside the tahoe.cfg for a nodetype= directive, etc.
This also makes it easy to have "tahoe start BASEDIR" pass the rest of
its arguments on to twistd, so e.g. "tahoe start BASEDIR --nodaemon
--profile=prof.out" does what you'd expect "twistd --nodaemon
--profile=prof.out" to do. "tahoe run BASEDIR" is thus simply aliased to
"tahoe start BASEDIR --nodaemon". This removes the need to special-case
--profile and --syslog.
I also removed some of the default logging behavior:
before:
'tahoe start' = 'twistd --logfile BASEDIR logs/twistd.log'
'tahoe start --profile' adds '--profile=profiling_results.prof --savestats'
'tahoe run' = 'twistd --nodaemon --logfile BASEDIR/logs/tahoesvc.log'
after:
'tahoe start' = 'twistd --logfile BASEDIR logs/twistd.log'
unless --logfile, --nodaemon, or --syslog are passed
'tahoe start --profile' invalid, use 'tahoe start --profile=OUTPUT'
'tahoe run' = 'twistd --nodaemon'
so log messages go to stdout
This finally enables 'tahoe run' to work with all node types, including
the key-generator and stats-gatherer.
It gets 'tahoe start' one step closer to accepting --reactor= . To
actually accomplish this will require this file, the enclosing
__init_.py files, and everything they import to avoid importing the
reactor. (if anything imports twisted.internet.reactor before
startstop_node.start() gets to run, then --reactor= comes too late).
That will take a lot of work, and requires lazy-loading of many core
libraries (foolscap.logging in particular), and removing a lot of code
from src/allmydata/__init__.py .
Note fix following issues from origial commit:
refactor unittests, fix style, add test
(0) use CommonFixture as mixin to increase DRYness
(1) self.failUnlessIn('size', metadata.keys()) --> self.failUnlessIn('size', metdata)
(2) test_size_is_not_None --> test_size_is_0 AND test_size_is_1000
The stdlib 'subprocess' module in python-2.7.4 through 2.7.7 suffers
from http://bugs.python.org/issue18851 which causes unrelated file
descriptors to be closed when `subprocess.call()` fails the `exec()`,
such as when the executable being invoked does not actually exist. There
appears to be some randomness involved. This was fixed in python-2.7.8.
Tahoe's iputil.py uses subprocess.call on many different "ifconfig"-type
executables, most of which don't exist on any given platform (added in
git commit 8e31d66cd0). This results in a lot of file-descriptor
closing, which (at least during unit tests) tends to clobber important
things like Tub TCP sockets. This seems to be the root cause behind
ticket:2121, in which normal code tries to close already-closed sockets,
crashing the unit tests. Since different platforms have different
ifconfigs, some platforms will experience more failed execs than others,
so this bug could easily behave differently on linux vs freebsd, as well
as working normally on python-2.7.8 or 2.7.4.
This patch inserts a guard to make sure that os.path.isfile() is true
before allowing Popen.call() to try executing the target. This ought to
be enough to avoid the bug. It changes both iputil.py and
allmydata.__init__ (which uses Popen for calling "lsb_release"), which
are all the places where 'subprocess' is used outside of unit tests.
Other potential fixes: use the 'subprocess32' module from PyPI (which is
a bug-free backport of the Python3 stdlib subprocess module, but would
introduce a new dependency), or require python >= 2.7.8 (but this would
rule out development/deployment on the current OS-X 10.9 release, which
ships with 2.7.5, as well as other distributions like Ubuntu 14.04 LTS).
I believe this closes ticket:2121, and given the apparent relationship
between 2121 and 2023, I think it also closes ticket:2023 (although
since 2023 doesn't have copies of the failing log files, it's hard to
tell). I'm hoping that this will tide us over until 1.11 is released, at
which point we can execute on the plan to remove iputil.py entirely by
changing the way that nodes learn their externally-facing IP address.
Some Travis-CI workers report persistently empty disks, causing spurious
test failures. It's not really that important to assert used>0, so this
relaxes the test.
Closes ticket:2290
Closes ticket:2281 (trac).
This removes src/allmydata/test/trial_coverage.py, which was a
in-process way to run trial tests under the "coverage" code-coverage
tool. These days, the preferred way to do this is with "coverage run",
although the actual invocation is a bit messy because of the way
bin/trial uses subprocess.call() to invoke the real entrypoint script
with the right PYTHONPATH (see #1698 for details). Hopefully this will
be improved to use a simpler "coverage run .." command in the future.
This patch also removes twisted/plugins/allmydata_trial.py, which
enabled the "--reporter=bwverbose-coverage" option. Finally it modifies
setup.py to stop looking for that option and adding "trialcoverage" to
the dependencies list, which gets us closer to removing "setup_requires"
entirely.
The new rules for "bin/tahoe ARG1.. SUBCOMMAND ARG2.." arg:
* --node-directory is only accepted in ARG1, not ARG2
* create-*/start/stop/restart accept --basedir in ARG2, or an explicit
basedir argument
* only one of --node-directory/--basedir/explicit-basedir is accepted
* --quiet/--version is only accepted in ARG1, not ARG2
Closes#166
This should now fail quickly (during "tahoe start"). Previously this
would silently treat an unparseable size as "0", and the only way to
discover that it had had a problem would be to look at the foolscap log,
or examine the storage-service web page for the unexpected "Reserved
Size" number.
Previously, Introducers always used a swissnum of "introducer", so
anyone who could learn the (public) tubid of the introducer would be
able to connect to and use it. This changes new Introducers to use the
same randomly-generated swissnum as clients and storage servers do, so
that you absolutely must learn the introducer.furl from someone who
knows it already before you can connect.
This change also moves the location of the file that stores
introducer.furl from BASEDIR/introducer.furl to
BASEDIR/private/introducer.furl, since that's where we keep the private
things. The first time an introducer is started with the new code, it
will move any existing BASEDIR/introducer.furl into the new place.
Note that this will not change the FURL of existing introducers: it will
only affect newly created ones. When you change an introducer's FURL,
you must also update all of the nodes (clients and storage servers)
which connect to it, so upgrading it to an unguessable one isn't
something we should do automatically.
This stores the sequence number in BASEDIR/announcement-seqnum, and
increments it each time any service is published (every service
announcement is regenerated with the new sequence number). As everyone
knows, time is an illusion, and occasionally goes backwards, so a
counter is generally safer (and reveals less information about the
node).
Later, we'll improve the introducer client to tolerate rollbacks (where,
perhaps due to a VM being restarted from an earlier checkpoint, the
stored sequence number reverts to an earlier version).
twisted.web.html.escape was used to produce html-encoded string (to then look
it up in "value" attribute), but behavior of that function has changed between
Twisted 12.2.0 (simple custom implementation) and 12.3.0 (imported from stdlib
cgi module).
This also simplifies how case-insensitivity is handled, and fixes a corner case
where the wrong exception was raised when the size ends in "BB".
fixes#1812
Signed-off-by: David-Sarah Hopwood <davidsarah@mint>
This contains several merged patches. Individual messages follow, latest first:
* Fix a warning from check-miscaptures.
* In retrieve.py, explicitly test whether a key is in self.servermap.proxies
rather than catching KeyError.
* Added a new comment to the MDMF version of the test I removed, explaining
the removal of the SDMF version.
* Removed test_corrupt_all_block_hash_tree_late, since the entire block_hash_tree
is cached in the servermap for an SDMF file.
* Fixed several tests that require files larger than the servermap cache.
* Remove unused test_response_cache_memory_leak().
* Exercise the cache.
* Test infrastructure for counting cache misses on MDMF files.
* Removed the ResponseCache. Instead, the MDMFSlotReadProxy initialized
by ServerMap is kept around so Retrieve can access it. The ReadProxy
has a cache of the first 1000 bytes initially read from each share by
the ServerMap. We're able to satisfy a number of requests out of this
cache, so roundtrips are reduced from 84 to 60 in test_deepcheck_mdmf.
There is still some mystery about under what conditions the cache has
fewer than 1000 bytes. Also this breaks some existing unit tests that
depend on the inner behavior of ResponseCache.
* The servermap.proxies (a cache of SlotReadProxies) is now keyed
by (verinfo,serverid,shnum) rather than just (serverid,shnum)
* Minor cosmetic changes
* Added a test failure if the number of cache misses is too high.
Author: Andrew Miller <amiller@dappervision.com>
Signed-off-by: David-Sarah Hopwood <davidsarah@jacaranda.org>
This prints out which things are different when two sets are expected to be the
same. This was useful to me when debugging the code under test. Hm, this
pattern might be more generally useful...
This probably only works on Linux. It uses sudo to mount and unmount the tmpfs,
which may prompt for a password. refs #20
Signed-off-by: David-Sarah Hopwood <david-sarah@jacaranda.org>
Nevow automatically HTML-escapes strings passed in stan without a raw marker.
Written by MK_FG. fixes#1143
Signed-off-by: David-Sarah Hopwood <david-sarah@jacaranda.org>
The wait_for_connections() method, which is used at the start of
test_system to make sure that all the clients are connected to all the
servers, did not also wait for clients to be connected to their Helpers.
Every once in a while, the helper connection would take a bit longer,
and then
test_system.SystemTest.test_filesystem._test_web._got_welcome_helper
would fail, because we'd check for a helper connection before it was
ready.
The fix is to modify wait_for_connections's polling predicate to look
for helper connections (if configured) as well as the regular
introducer- and server- connections.
Tested by temporarily adding a large (30s) delay to the connectTo() call
in Uploader.startService, simulating a long helper
connection-establishment delay. This makes the test fail consistently.
Then I fixed wait_for_connections(), and the test passed (slowly). Then
I removed the delay.
Closes#1467
This makes it easy to distinguish between old V1-Introducer
nodes (identified by their Foolscap TubID) and new V2 nodes (identified
by their ed25519 pubkey).
This fixes a few places where we used to display a tubid even if we had
a pubkey, making it hard to visually correlate servers in two different
displays. It also cleans up the way we pass serverids to the JS-based
download timeline.
The "introweb" subscribed-clients list still shows tubids.
The _upload_resumable() test interrupts a Helper upload partway
through (by shutting down the Helper), then restarts the Helper and
resumes the upload. The control flow is kind of tricky: to do anything
"partway through" requires adding a hook to the Uploadable. The previous
flow depended upon a (fragile) call to self.stall(), which waits a fixed
number of seconds.
This removes one of those stall() calls (the remainder is in
test/common.py and I'll try removing it in a subsequent revision). It
also removes some now-redundant wait_for_connections() calls, since
bounce_client() doesn't fire its Deferred until the client has finished
coming back up (and uses wait_for_connections() internally to do so).
DeepResultsBase also has a get_corrupt_shares(), and it is populated
from CheckResults.get_corrupt_shares(). It has been updated too, along
with get_remaining_corrupt_shares().
Remove temporary get_new_corrupt_shares() and
get_new_incompatible_shares().
This changes all code which feeds CheckResults(sharemap=) to provide
IServer instances, but CheckResults converts these to old-style
serverids during output, so downstream code doesn't have to change yet.
It adds a temporary get_new_sharemap(), which *does* return IServer
instances, so the immutable repairer can build new CheckResults from an
old one. This will go away when get_sharemap() is updated to return
IServer (and downstream code is updated too).
i.e. change set_data() to accept lots of parameters, instead of taking
a single dictionary with lots of keys. Also Convert all CheckResults
creators to use it.
The goal is to make CheckResults more strongly typed, and remove the
ambiguous ".data" field in favor of a bunch of specific counters and
sharelists, so I can changes .sharemap and .servermap to use IServer
instances instead of string serverids. By cleaning this up first, I hope
to get that task done with less debugging.
The Fake*Node classes in test/common.py were accumulating share data in
a class-level dictionary, which persisted from one test run to the next.
As a result, running test_web.py over and over (with trial's
--until-failure feature) made this dictionary grow without bound,
eventually running out of memory.
This fix moves that dictionary into the FakeClient built fresh for each
test, so it doesn't build up. It does the same thing for "file_types",
which was much smaller but still lived at the class level.
Closes#1729
This stores IDisplayableServer-providing instances (StubServers or
NativeStorageServers) in the .servermap and .sharemap dictionaries. But
get_servermap()/get_sharemap() still return data structures with
serverids, not IServers, by translating their data on the way out. This
lets us put off changing the callers for a little bit longer.
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 hides attributes with e.g. _sharemap, and creates getters like
get_sharemap() to access them, for every field except .uri . This will
make it easier to modify the internal representation of .sharemap
without requiring callers to adjust quite yet.
".uri" has so many users that it seemed better to update it in a
subsequent patch.
Populate most of UploadResults (except .uri, which is learned later when
using a Helper) in the constructor, instead of allowing creators to
write to attributes later. This will help isolate the fields that we
want to change to use IServers.
This splits the pb.Copyable on-wire object (HelperUploadResults) out
from the local results object (UploadResults). To maintain compatibility
with older Helpers, we have to leave pb.Copyable classes alone and
unmodified, but we want to change UploadResults to use IServers instead
of serverids. So by using a different class on the wire, and translating
to/from it on either end, we can accomplish both.
Unlike set.union(), which returns a new set, DictOfSets.union() modified
the DictOfSets in-place. The name collision bit me when I changed some
code from using DictOfSets to a normal set, and expected that
set.union() would modify the set in-place. Since there was only one user
of DictOfSets.union, I figured it was safer to just get rid of it.
If a server did not respond to the pre-repair filecheck, but did respond
to the repair, that server was not correctly added to the
RepairResults.data["servers-responding"] list. (This resulted from a
buggy usage of DictOfSets.union() in filenode.py).
In addition, servers to which filecheck queries were sent, but did not
respond, were incorrectly added to the servers-responding list
anyawys. (This resulted from code in the checker.py not paying attention
to the 'responded' flag).
The first bug was neatly masked by the second: it's pretty rare to have
a server suddenly start responding in the one-second window between a
filecheck and a subsequent repair, and if the server was around for the
filecheck, you'd never notice the problem. I only spotted the smelly
code while I was changing it for IServer cleanup purposes.
I added coverage to test_repairer.py for this. Trying to get that test
to fail before fixing the first bug is what led me to discover the
second bug. I also had to update test_corrupt_file_verno, since it was
incorrectly asserting that 10 servers responded, when in fact one of
them throws an error (but the second bug was causing it to be reported
anyways).
Previously, test_runner sometimes fails because the _node_has_started()
poller fires after the portnum file has been opened, but before it has
actually been filled, allowing the test process to observe an empty file,
which flunks the test.
This adds a new fileutil.write_atomically() function (using the usual
write-to-.tmp-then-rename approach), and uses it for both node.url and
client.port . These files are written a bit before the node is really up and
running, but they're late enough for test_runner's purposes, which is to know
when it's safe to read client.port and use 'tahoe restart' (and therefore
SIGINT) to restart the node.
The current node/client code doesn't offer any better "are you really done
with startup" indicator.. the ideal approach would be to either watch the
logfile, or connect to its flogport, but both are a hassle. Changing the node
to write out a new "all done" file would be intrusive for regular
operations.
t=info contains randomly-generated ophandles, and t=rename-form contains the
name of the child being renamed, so neither is eligible for a
short-circuiting ETag. Enhanced test_web to exercise this. Had to improve
FakeCHKFileNode slightly to let it participate. Refs #443.
test_web.py: use shouldFail2(), safer than old shouldFail()
directory.py: forbid slashes in from_name=, return BAD_REQUEST instead of
GONE when trying to move into a non-directory
The move webapi function now takes a target_type argument which lets it
know whether the target is a subdirectory name or URI. This is an
improvement over the old system in which the move handler tried to guess
whether the target was a name or a URI. Also fixed a little docs
copypaste problem and tweaked some line wrapping.
This adds "move file" capability to the web UI's directory display. The
support and test framework is heavily based on the similar "rename file"
feature. Unit tests and documentation are included. Multiple in-progress
versions of this patch may be found in ticket 1579. This version
includes arbitrary URI target support and is compatible with the change
from tahoe_css to tahoe.css.
'serverid' is the pubkey (for V2 clients), falling back to the tubid (for V1
clients). This also required cleaning up the way the index is created for the
old V1 introducer.
This significantly cleans up the IntroducerServer web-status renderers.
Instead of poking around in the introducer's internals, now the web-status
renderers get clean AnnouncementDescriptor and SubscriberDescriptor
objects. They are still somewhat foolscap-centric, but will provide a clean
abstraction boundary for future improvements.
The specific #1721 bug was that old (V1) subscribers were handled by
wrapping their RemoteReference in a special WrapV1SubscriberInV2Interface
object, but the web-status display was trying to peek inside the object to
learn what host+port it was associated with, and the wrapper did not proxy
those extra attributes.
A test was added to test_introducer to make sure the introweb page renders
properly and at least contains the nicknames of both the V1 and V2 clients.
This was a premature feature addition to the mock filenode, and gets in the
way of the IServer refactoring I'm trying to do. Best to remove it now and
re-introduce it in a better form later when it's actually needed.
This avoids the name collision between the actual results
objects (defined in allmydata.check_results) and the code that renders
these objects into HTML (defined in allmydata.web.check_results). Only
the web-side objects were renamed.
SystemTest has a couple of different phases, separated by a poller which
waits for everything to be idle (all messages delivered, none in flight). It
does this by watching some internal "_debug_outstanding" counters in the
server and in each client, and waiting for them to hit zero.
Just before the last phase, we replace the server with a new one (to make
sure clients re-send their messages properly). Unfortunately, the polling
function closed over the variable holding the original server, and didn't see
the replacement. It kept polling the old server, and failed to notice the
outstanding messages for the new server. The last phase of the test (check3)
was started too early, which failed (since some messages had not yet been
delivered), and then exploded in a flurry of dirty-reactor errors (because
some messages were delivered after test shutdown).
This replaces the closed-over-variable with a "self.the_introducer", which
seems to fix the race.
One additional place to look at in the future: the client
announcement-receive path (remote_announce) uses an eventually(). If the
message has been received and the eventual-send posted (but not yet executed)
when the poller sees it, the poller might erroneously conclude that the
client is idle and cause the same problem as above. To fix this, the poller
(probably all pollers) could be enhanced to do a flushEventualQueue before
querying the are-we-done-yet predicate function.
This introduces new client and server halves to the Introducer (renaming the
old one with a _V1 suffix). Both have fallbacks to accomodate talking to a
different version: the publishing client switches on whether the server's
.get_version() advertises V2 support, the server switches on which
subscription method was invoked by the subscribing client.
The V2 protocol sends a three-tuple of (serialized announcement dictionary,
signature, pubkey) for each announcement. The V2 server dispatches messages
to subscribers according to the service-name, and throws errors for invalid
signatures, but does not otherwise examine the messages. The V2 receiver's
subscription callback will receive a (serverid, ann_dict) pair. The
'serverid' will be equal to the pubkey if all of the following are true:
the originating client is V2, and was told a privkey to use
the announcement went through a V2 server
the signature is valid
If not, 'serverid' will be equal to the tubid portion of the announced FURL,
as was the case for V1 receivers.
Servers will create a keypair if one does not exist yet, stored in
private/server.privkey .
The signed announcement dictionary puts the server FURL in a key named
"anonymous-storage-FURL", which anticipates upcoming Accounting-related
changes in the server advertisements. It also provides a key named
"permutation-seed-base32" to tell clients what permutation seed to use. This
is computed at startup, using tubid if there are existing shares, otherwise
the pubkey, to retain share-order compatibility for existing servers.
test_verify_mdmf_all_bad_sharedata tests for the regression described
in ticket 1648. In particular, it will trigger the misplaced assertion
in the share activation code. It also tests to make sure that
verification continues with fewer than k shares.
The remaining work is to write additional tests.
src/allmydata/test/no_network.py:
This supports tests in which servers leave the grid only to return with
their shares intact at a later time.
src/allmydata/test/test_mutable.py:
The UCWEs in the incident reports associated with #1628 all seem to be
associated with shares that the servermap knows about, but which aren't
accounted for during the publish process for whatever reason. Specifically,
it looks like the publisher is only capable of keeping track of a single
storage server for a given share. This makes the repair process worse than
it was pre-MDMF at updating all of the shares of a particular file to the
newest version, and can also cause spurious UCWEs. This test simulates such
a layout and fails if an UCWE is thrown. We need to write another test to
ensure that all copies of a share are updated to the latest version (or
alter this test to do that), so that the test suite doesn't pass unless both
regressions are fixed.
We want the publisher to follow the existing share placement when uploading
a new version of a mutable file, and we don't want this test to pass unless
it does.
src/allmydata/mutable/publish.py:
Before this commit, the publisher only kept track of a single writer for
each share. This is insufficient to handle updates in which a single share
may live on multiple servers. In the best case, an update will only update
one of the existing shares instead of all of them. In some cases, the update
will encounter the existing shares when publishing some other share,
interpret it as a sign of an uncoordinated update, and fail. Keeping track
of all of the writers helps ensure that all existing shares are updated, and
helps avoid spurious uncoordinated write errors.
We're slowly moving away from Nevow, and marcusw's previous patch removed
uses of the formless CSS file, so now we can stop testing that nevow can find
that file, and remove the lingering unused "import formless" call.
* use d3.js v2.4.6
* add a "toggle misc events" button, to get hash/bitmap-checking details
* only draw data that's on screen, for speed
* add fragment-arg to fetch timeline data.json from somewhere else
rolling back:
Thu Sep 29 23:46:28 MDT 2011 zooko@zooko.com
* debugprint the values of blocks and hashes thereof; make the test data and the seg size small in order to make the debugprints easy to look at
M ./src/allmydata/mutable/publish.py -1 +2
M ./src/allmydata/mutable/retrieve.py +3
M ./src/allmydata/test/test_mutable.py -2 +2
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.
* fix tahoe.cfg control of default mutable type
* tolerate arbitrary case in [client]mutable.format value
* small docs improvements
* use get_mutable_type() as a format-is-mutable predicate
* tighten up error message
* fix CLI commands (put, mkdir) to send format=, not mutable-type=
* fix tests
* test_cli: fix tests that observe t=json output, don't ignore failures in
'tahoe put'
* fix handling of version= to make it easier to use the default
* interpret ?mutable=true&format=MDMF as MDMF, not SDMF
The filecaps used to be produced with hints for 'k' and segsize, but they
weren't actually used, and doing so had the potential to limit how we change
those filecaps in the future. Also the parsing code had some problems dealing
with other numbers of extensions. Removing the existing fields and making the
parser tolerate (and ignore) extra ones makes MDMF more future-proof.
We're removing this function because it is currently unused, because it is dangerous, and because the bug described in #1528 leaks the cancellation secret, which allows anyone who knows a file's storage index to abuse this function to delete shares of that file.
ref. #1528
This check needs to be done with each fetch from the storage server, to
detect when someone has changed the share (i.e. our servermap goes stale).
Doing it just once at the beginning of retrieve isn't enough: a write might
occur after the first segment but before the second, etc.
_try_to_validate_prefix() was not removed: it will be used by the future
check-with-each-fetch code.
test_mutable.Roundtrip.test_corrupt_all_seqnum_late was disabled, since it
fails until this check is brought back. (the corruption it applies only
touches the prefix, not the block data, so the check-less retrieve actually
tolerates it). Don't forget to re-enable it once the check is brought back.
This is a neat trick to reduce Foolscap overhead, but the need for an
explicit flush() complicates the Retrieve path and makes it prone to
lost-progress bugs.
Also change test_mutable.FakeStorageServer to tolerate multiple reads of the
same share in a row, a limitation exposed by turning off the queue.
Note that the downloader will still fetch a segment for a zero-length
read, which is wasteful. Fixing that isn't specifically required to fix
#1512, but it should probably be fixed before 1.9.
This first step shaves 15% off the runtime: from 139s to 119s on my laptop.
It also fixes a couple of places where a Deferred was being dropped, which
would cause two tests to run in parallel and also confuse error reporting.
This consistently records all immutable uploads in the Recent Uploads And
Downloads page, regardless of code path. Previously, certain webapi upload
operations (like PUT /uri/$DIRCAP/newchildname) failed to pass the History
object and were left out.
Without this, we get a regression when modifying a mutable file that was
created with more shares (larger N) than our current tahoe.cfg . The
modification attempt creates new versions of the (0,1,..,newN-1) shares, but
leaves the old versions of the (newN,..,oldN-1) shares alone (and throws a
assertion error in SDMFSlotWriteProxy.finish_publishing in the process).
The mixed versions that result (some shares with e.g. N=10, some with N=20,
such that both versions are recoverable) cause problems for the Publish code,
even before MDMF landed. Might be related to refs #1390 and refs #1042.
