This allows things like Command.Find to use noMessages and generate their
own complete json objects. Previouly, Command.Find managed that only via a
hack, which wasn't compatable with batch mode.
Only Command.Find, Command.Smudge, and Commange.Status use noMessages
currently, and none except for Command.Find are impacted by this change.
Fixes find --json --batch output
Writes are optimised by queueing up multiple writes when possible.
The queue is flushed after the Annex monad action finishes. That makes it
happen on program termination, and also whenever a nested Annex monad action
finishes.
Reads are optimised by checking once (per AnnexState) if the database
exists. If the database doesn't exist yet, all reads return mempty.
Reads also cause queued writes to be flushed, so reads will always be
consistent with writes (as long as they're made inside the same Annex monad).
A future optimisation path would be to determine when that's not necessary,
which is probably most of the time, and avoid flushing unncessarily.
Design notes for this commit:
- separate reads from writes
- reuse a handle which is left open until program
exit or until the MVar goes out of scope (and autoclosed then)
- writes are queued
- queue is flushed periodically
- immediate queue flush before any read
- auto-flush queue when database handle is garbage collected
- flush queue on exit from Annex monad
(Note that this may happen repeatedly for a single database connection;
or a connection may be reused for multiple Annex monad actions,
possibly even concurrent ones.)
- if database does not exist (or is empty) the handle
is not opened by reads; reads instead return empty results
- writes open the handle if it was not open previously
Came up with a generic way to filter out progress messages while keeping
errors, for commands that use stderr for both.
--json mode will disable command outputs too.
Removed old extensible-exceptions, only needed for very old ghc.
Made webdav use Utility.Exception, to work after some changes in DAV's
exception handling.
Removed Annex.Exception. Mostly this was trivial, but note that
tryAnnex is replaced with tryNonAsync and catchAnnex replaced with
catchNonAsync. In theory that could be a behavior change, since the former
caught all exceptions, and the latter don't catch async exceptions.
However, in practice, nothing in the Annex monad uses async exceptions.
Grepping for throwTo and killThread only find stuff in the assistant,
which does not seem related.
Command.Add.undo is changed to accept a SomeException, and things
that use it for rollback now catch non-async exceptions, rather than
only IOExceptions.
Turns out that a lot of the time spent in a bulk add was just updating the
add alert to rotate through each file that was added. Showing one alert
makes for a significant speedup.
Also, when the webapp is open, this makes it take quite a lot less cpu
during bulk adds.
Also, it lets the user know when a bulk add happened, which is sorta
nice..
There was confusion in different parts of the progress bar code about
whether an update contained the total number of bytes transferred, or the
number of bytes transferred since the last update. One way this bug
showed up was progress bars that seemed to stick at zero for a long time.
In order to fix it comprehensively, I add a new BytesProcessed data type,
that is explicitly a total quantity of bytes, not a delta.
Note that this doesn't necessarily fix every problem with progress bars.
Particularly, buffering can now cause progress bars to seem to run ahead
of transfers, reaching 100% when data is still being uploaded.
The caller may be like glacier, and be running an action that may print
a message and fail. So don't start displaying the meter until data is
flowing, to avoid getting in the way of such messages being displayed.
This was shown redundantly for a tricky reason -- while it runs
inside a doSideAction block that would appear to supress it,
the action being run is in a different state monad; for the remote,
and so the suppression doesn't work.
Always suppressing the message when committing to a local remote is
ok do to though -- it mirrors the /dev/nulling of the git annex shell commit
output. And it turns out that any time there is a git-annex branch state
change to commit on the remote, the local repo has also had a similar
change made, and so the message has been shown already.
A bit tricky to avoid printing it twice in a row when there are queued git
commands to run and journal to stage.
Added a generic way to run an action that may output multiple side
messages, with only the first displayed.
Under ghc 7.4, this seems to be able to handle all filename encodings
again. Including filename encodings that do not match the LANG setting.
I think this will not work with earlier versions of ghc, it uses some ghc
internals.
Turns out that ghc 7.4 has a special filesystem encoding that it uses when
reading/writing filenames (as FilePaths). This encoding is documented
to allow "arbitrary undecodable bytes to be round-tripped through it".
So, to get FilePaths from eg, git ls-files, set the Handle that is reading
from git to use this encoding. Then things basically just work.
However, I have not found a way to make Text read using this encoding.
Text really does assume unicode. So I had to switch back to using String
when reading/writing data to git. Which is a pity, because it's some
percent slower, but at least it works.
Note that stdout and stderr also have to be set to this encoding, or
printing out filenames that contain undecodable bytes causes a crash.
IMHO this is a misfeature in ghc, that the user can pass you a filename,
which you can readFile, etc, but that default, putStr of filename may
cause a crash!
Git.CheckAttr gave me special trouble, because the filenames I got back
from git, after feeding them in, had further encoding breakage.
Rather than try to deal with that, I just zip up the input filenames
with the attributes. Which must be returned in the same order queried
for this to work.
Also of note is an apparent GHC bug I worked around in Git.CheckAttr. It
used to forkProcess and feed git from the child process. Unfortunatly,
after this forkProcess, accessing the `files` variable from the parent
returns []. Not the value that was passed into the function. This screams
of a bad bug, that's clobbering a variable, but for now I just avoid
forkProcess there to work around it. That forkProcess was itself only added
because of a ghc bug, #624389. I've confirmed that the test case for that
bug doesn't reproduce it with ghc 7.4. So that's ok, except for the new ghc
bug I have not isolated and reported. Why does this simple bit of code
magnet the ghc bugs? :)
Also, the symlink touching code is currently broken, when used on utf-8
filenames in a non-utf-8 locale, or probably on any filename containing
undecodable bytes, and I temporarily commented it out.
The bug was that with --json, output lines were sometimes doubled. For
example, git annex init --json would output two lines, despite only running
one thing. Adding to the weirdness, this only occurred when the output
was redirected to a pipe or a file.
Strace showed two processes outputting the same buffered output.
The second process was this writer process (only needed to work around
bug #624389):
_ <- forkProcess $ do
hPutStr toh $ unlines paths
hClose toh
exitSuccess
The doubled output occurs when this process exits, and ghc flushes the
inherited stdout buffer. Why only when piping? I don't know, but ghc may
be behaving differently when stdout is not a terminal.
While this is quite possibly a ghc bug, there is a nice fix in git-annex.
Explicitly flushing after each chunk of json is output works around the
problem, and as a side effect, json is streamed rather than being output
all at the end when performing an expensive operaition.
However, note that this means all uses of putStr in git-annex must be
explicitly flushed. The others were, already.
Left out the backend usage graph for now, and bad/temp directory sizes
are only displayed when present. Also, disk usage is returned as a string
with units, which I can see changing later.
Adds a missing newline when a longnote is followed by a endresult.
Multiple longnotes in a row will now be separated by a blank line, which
could be a bug or a feature depending on taste.
Removed several places where newlines were explicitly displayed after
longnotes.
This includes a generic JSONStream library built on top of Text.JSON
(somewhat hackishly).
It would be possible to stream out a single json document describing
all actions, but it's probably better for consumers if they can expect
one json document per line, so I did it that way instead.
Output from external programs used for transferring files is not
currently hidden when outputting json, which probably makes it not very
useful there. This may be dealt with if there is demand for json
output for --get or --move to be parsable.
The version, status, and find subcommands have hand-crafted output and
don't do json. The whereis subcommand needs to be modified to produce
useful json.
Haskell's IO layer crashes on characters > 255 when in a non-unicode (latin1)
locale. Until Haskell gets better behavior, put in an admittedly ugly
workaround for that: git-annex forces utf8 output mode no matter what
locale is selected. So if you use a non-utf8 locale, your filenames with
characters > 127 will not be displayed as you'd expect. But at least it
won't crash.
Based on http://hackage.haskell.org/trac/ghc/ticket/3307 ,
whether FilePath contains decoded unicode varies by OS.
So, add a configure check for it.
Also, renamed showFile to filePathToString
Internally, the filenames are stored as un-decoded unicode.
I tried decoding them, but then haskell tries to access the wrong files.
Hmm.
So, I've unhappily chosen option "B", which is to decode filenames before
they are displayed.
Moved away from a map of flags to storing config directly in the AnnexState
structure. Got rid of most accessor functions in Annex.
This allowed supporting multiple --exclude flags.
