at one point I'd thrown in a 'str' since fuse api bits required a str instance
but tahoe returns unicode objects from its json parsing. that, naturally
enough should really be a utf8 encoded str of the unicode object...
1. changed the node's exit-on-error behaviour. rather than logging debug and
then delegating to self for _abort_process() instead simply delegate to self
_service_startup_failed(failure) to report failures in the startup deferred
chain. subclasses then have complete control of handling and reporting any
failures in node startup.
2. replace the convoluted wx.PostEvent() glue for posting an event into the
gui thread with the simpler expedient of wx.CallAfter() which is much like
foolscap's eventually() but also thread safe for inducing a call back on the
gui thread.
in certain cases (e.g. the node.pem changed but old .furls are in private/)
the node will abort upon startup. previously it used os.abort() which in these
cases caused the mac gui app to crash on startup with no explanation.
this changes that behaviour from calling os.abort() to calling
node._abort_process(failure) which by default calls os.abort(). this allows
that method to be overridden in subclasses.
the mac app now provides and uses such a subclass of Client, so that failures
are reported to the user in a message dialog before the process exits.
this uses wx.PostEvent() with a custom event type to signal from the reactor
thread into the gui thread.
the confwiz now uses socket.gethostname() if a 'nickname' file doesn't already
exist, and passes that nickname into the 'record_install' method on the backend,
so that the moniker can be recorded in the system table.
when an operation takes 'too long', on 10.4 the user gets a dialog about
the problem with a 'force eject / keep trying' choice. on 10.5 the fuse
system seems to summarily unmount the drive.
this showed up in 10.5 testing because the time to open() a file depended
upon the size of the file, and an 8Mb test file took long enough for the
node to download that the open() call didn't respond within 60s and fuse
spontaneously ejected the drive, quitting the plugin (and cancelling the
download).
this changes the fuse options passed to the plugin by the ui when the
'mount filesystem' window is used. command line users should check out
the '-odaemon_timeout=...' option. this changes the default timeout from
60s to 300s (5min) for ui launched plugins.
this will be addressed in a deeper manner at a later date, with a more
advanced fuse subsystem which can interleave open()/read() with the
actual download of the file, only blocking when data is not downloaded
yet.
various updates to improve the functionality of the mac fuse plugin
1. caching
previously, the experimental tahoefuse plugin pre-loaded the whole
structure of the specified mount into memory at launch time. changes
which were made through that fuse plugin would be remembered, but any
changes made through other tahoe clients would not be reflected.
now directory contents are only loaded when needed, and the data is
cached for a limited time. any use of Directory objects should first
call maybe_refresh() which will check the time since the cache was last
loaded, and if the data is older than some validity period (currently
26s) then the directory's contents will be refetched and reloaded.
this replaces the 'load_dir()' method of TFS
whenever a local change is made to a Directory object, or when the
aforementioned cache reloading notices a change in directory data, the
mtime of the directory is automatically updated.
2. stat / metadata
the retrieval of 'stat' information for getattr(), and the way that
metadata is handled, has been refactored to better reflect the fact that
metadata in tahoe is only represented by 'edges' (i.e entries in
directories) not on 'nodes' (files or directories themselves) hence a
stat lookup should be a query to the parent directory (specifically the
parent specified by the path being queried in the case that a node has
multiple parents) for details known by that directory for the given
child, rather than a query to the child itself.
the TStat utility class for returning stat information to the python-
fuse layer has been extended to accept a 'metadata' argument in its
constructor. any fields found in the metadata dict which match the
names of the stat attributes are loaded into the TStat object. the
'ctime' and 'mtime' attributes are translated to st_ctime and st_mtime
to mesh with the existing timestamp handling code. any fields specified
by kwargs to the constructor override things that might be loaded from
the metadata dict.
Directory objects now track their children as a dict mapping name to
(child_obj, metadata) tuples. This is because the metadata in tahoe
will be stored exclusively on the edges of the graph. each Directory
maintains its own mtime however, and get_stat() calls will report the
mtime of a directory based on the last modification of the Directory
object, not based on any mtime records from the parent directory's
metadata for that child. This addresses the fact that since directories
may be shared, a given parent may or may not reflect the latest changes,
however one of the Finder's behaviours is to examine the stat of a
directory, and not to bother doing a readdir() if the stat is unchanged.
i.e. unless directories report their changes in their stat info, the
Finder will not show changes within that directory.
3. refactoring
reporting of many error codes has been refactored to raise IOError
subclasses with the appropriate errno. this exploits python-fuse's
built-in mechanism for catching IOError and reporting the errno
embedded within it automatically, while simplifying the code within
the plugin.
the add_child() method on TFS was removed in favour of simply having an
add_child() method on Directory objects. this provides a more OO
approach in that Directory is responsible for maintaining its own in
memory state and also writing changes back to the node. similarly for
remove_child()
these changes, along with the new tfs.compose_url() method,
significantly simplify and improve readability of mkdir, rename methods
along with the newer link and unlink. these also get improved error
reporting.
various operations (chmod, chown, truncate, utime) are now ignored.
previously they would report an unsupported operation (EOPNOTSUPP)
but now are simply logged and ignored. this surpresses errors caused
by some client programs which try to use these operations, but at the
moment those operations are meaningless to the tahoe filesystem anyway.
4. link / unlink / rmdir
link, symlink calls are now supported, though with semantics differing
from posix, both equivalent. unlink, rmdir calls are now supported,
also equivalent.
link or symlink calls duplicate the uri of the named source and adds it
as a child of another directory according to the destination path. for
directories, this creates a 'hard' link, i.e. the same directory will
appear in multiple locations within the filesystem, and changes in
any place will be reflected everywhere. for files, by contrast, since
the uri being duplicated is an immutable CHK uri, link/symlink for files
is equivalent to a copy - though significantly cheaper. (a file copy
with the fuse plugin is likely to cause a new file to be written and
uploaded, the link command simply adds an entry referring to an
existing uri)
in testing, the 'ln' command is unable to make hard links (i.e. call
link()) for directories, though symlink ('ln -s') is supported.
either forms works equivalently for files.
unlink and rmdir both remove the specified entry from its parent
directory.
5. logging
the 'tfuse.log' file now only reports launches of the fuse plugin. once
the plugin has parsed the options, it reopens the log file with the
name of the mount, e.g. tfuse.root_dir.log, so that multiple instances
running concurrently will not interfere with each others' logging.
6. bug fixes
the tmp_file in the cache dir backing files opened for write was
intermittently failing to open the file. added O_CREAT to the os.open
call so that files will be created if missing, not throw errors.
a failure to correctly parse arguments if no mount (dir_cap) name was
given but also no fuse options were given has been fixed. now the
command 'tahoe fuse mountpoint' will correctly default to root_dir
also when running from source, arguments to tahoefuse were not handled
to correctly match the 'tahoe fuse ...' behaviour.
Unfinished bits: doc in webapi.txt, test handling of badly formed JSON, return reasonable HTTP response, examination of the effect of this patch on code coverage -- but I'm committing it anyway because MikeB can use it and I'm being called to dinner...
