[tahoe-dev] git-annex and tahoe-lafs as a special remote -- in progress and testing

[Zooko O'Whielacronx]

Hi Jimmy:

I looked up more details about your Tahoe-LAFS configuration for git-annex:

http://git-annex.branchable.com/forum/tips:_special__95__remotes__47__hook_with_tahoe-lafs/

Here are the core configurations:

git config annex.tahoe-store-hook 'tahoe mkdir
tahoe:$ANNEX_HASH_1/$ANNEX_HASH_2 && tahoe put $ANNEX_FILE
tahoe:$ANNEX_KEY'
git config annex.tahoe-retrieve-hook 'tahoe get
tahoe:$ANNEX_HASH_1/$ANNEX_HASH_2/$ANNEX_KEY $ANNEX_FILE'
git config annex.tahoe-remove-hook 'tahoe rm
tahoe:$ANNEX_HASH_1/$ANNEX_HASH_2/$ANNEX_KEY'
git config annex.tahoe-checkpresent-hook 'tahoe ls
tahoe:$ANNEX_HASH_1/$ANNEX_HASH_2/$ANNEX_KEY 2>&1 || echo FAIL'

Hm, there are several things that I don't understand about this. Let's
see if there is doc about these hooks... Oh yes, there is good doc
here:

http://git.kitenet.net/?p=git-annex;a=blob;f=doc/special_remotes/hook.mdwn;h=9a7dbf7a1909e8460e8acc5eddc83bcc99665a27;hb=e72c1c33ae60f7fe544acd0a1f1331138b880e22

Okay, it appears to me that the tahoe-store-hook shown above creates a
two-level-deep directory structure and then doesn't use it, but
instead plonks the data into a file in the root dir (named "tahoe:")
under a file who filename equals $ANNEX_KEY.

This is extremely inefficient, because "tahoe mkdir" is a regrettably
slow operation (it might take around 1 second), and also because the
tahoe: directory will grow to be quite large and all reads or writes
of it are O(N) currently, so it will get slower and slower.

Hm, also it looks to me like tahoe-retrieve-hook will fail to find the
data that it was asked for since it is looking inside those
directories and that's not where the file was written to. Have you
tried it? :-)

Once it works, you should probably add Tahoe-LAFS to this list of back ends:

http://git-annex.branchable.com/special_remotes/

Regards,

Zooko