[haiku] Re: Need Some GSoC Advice

  • From: Ingo Weinhold <ingo_weinhold@xxxxxx>
  • To: haiku@xxxxxxxxxxxxx
  • Date: Tue, 24 Mar 2009 02:06:21 +0100

On 2009-03-23 at 23:54:25 [+0100], Cyan <cyanh256@xxxxxxxxxxxx> wrote:
> Humdinger <humdingerb@xxxxxxxxxxxxxx> wrote:
> > > A correct read/write implementation would have to update the
> > > indexes regardless.
> > IC. Then let's hope for correct implementations. :)
> 
> Would it be technically feasible (with modifications to the file
> system driver if necessary) to perform a query for all files which
> *lack* a particular attribute?

Not really. At least not efficiently with BFS. An index only contains the 
nodes that have the respective attribute, so it doesn't know about the 
others. That is as main index for the query one would have to use an index 
that contains all nodes/entries (name, size, last_modified), which will be 
quite inefficient.

[...]
> As for the indexer itself, it sounds like a great idea! I think the
> index data would need to be stored as BFS attributes as others have
> suggested -- a separate database would be a kludge IMO, and likely
> to lead to sync problems.

I don't think BFS is particularly well suited for this task and other file 
systems will need a database anyway. So a database per volume tailored to 
that purpose is the way to go IMHO.

CU, Ingo

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