[tahoe-dev] CLI mkdir inverse?

[Ben Hyde]

Thanks.  Gotcha.  I've closed and commented the bug i opened: http://allmydata.org/trac/tahoe/ticket/695

On May 4, 2009, at 4:08 PM, Brian Warner wrote:
> On Mon, 4 May 2009 09:32:17 -0400
> Ben Hyde <bhyde at pobox.com> wrote:
>
>> That was my first guess; but then I created an alias - letting it  
>> do the
>> mkdir for me - and I am unable to rm that alias.
>> ...
>>
>> Hm, now I'm thinking this is, in part, because I created the alias
>> example via 'tahoe create-alias example'; i.e. let it do the mkdir.
>> So there isn't anything to unlink it from.
>
> Bingo. "rm" is used to remove a link: a link from some parent  
> directory to
> some child object (a file or a subdirectory). Your top-level alias  
> isn't a
> child of anything: the only place that remembers it is your aliases  
> table (in
> ~/.tahoe/private/aliases). If you want to forget about it, just edit  
> that
> file and remove the line.
>
> "tahoe mkdir" does two things: create a dircap for a new empty  
> directory, and
> possibly write that dircap into some existing parent directory  
> associated
> with a given child name. If you just do "tahoe mkdir" with no  
> arguments, it
> only does the first part, and returns the dircap. If you do "tahoe  
> mkdir
> alias:subdir" or "tahoe mkdir alias:intermediatedir/subdir", it will  
> do both
> parts (possibly multiple times, if it must create intermediate  
> directories in
> the process).
>
> "tahoe create-alias ALIASNAME" does two things: create a dircap for  
> a new
> empty directory, and add that dircap into ~/.tahoe/private/aliases  
> associated
> with the given aliasname. This alises file is a local (real) file,  
> not stored
> in the tahoe grid, so "rm" doesn't know anything about it.
>
> Remember that Tahoe doesn't have explicit/immediate garbage  
> collection: "rm"
> merely forgets about the reference, it doesn't instantly free up the  
> space
> for the objects that are no longer reachable. If you turn periodic  
> GC on (see
> docs/garbage-collection.txt for details), then the fact that those  
> objects
> are no longer reachable will eventually cause them to be collected,  
> since
> they wouldn't have their leases renewed.
>
> cheers,
> -Brian
>