new IndexReader on empty Index

Hi,

Is there a reason it isn't possible to create a new
IndexReader on an
empty index? I get a Carp::confess() from
/usr/lib/perl5/vendor_perl/5.8.4/i686-linux/KinoSearch/Index
/IndexReader.pm
line 106.
This is with KinoSearch-0.20_04. Here is a snippet of code I
am using:
    my $hostname = hostname();
    die "Can't get unique hostname" unless
$hostname;

    my $invindex =
GT::Maildir::KinoSearch::Schema->open($path);
    my $lock_factory =
KinoSearch::Store::LockFactory->new(
        folder    => $invindex->get_folder,
        agent_id  => $hostname,
    );
    my $reader = KinoSearch::Index::IndexReader->open(
        invindex     => $invindex,
        lock_factory => $lock_factory,
    );
    return KinoSearch::Searcher->new(
        invindex => $invindex,
        reader   => $reader
    );

Am I doing something wrong?

Also, on a side note, the docs here:
http://www.rectangular.com/kin
osearch/docs/devel/KinoSearch/Store/LockFactory.html
say to use KinoSearch::Index::IndexReader->new(), not
->open(), but
that gives an error.

Thanks,

Scott

_______________________________________________
KinoSearch mailing list
KinoSearchrectangular.com
http://www.rectangular.com/mailman/listinfo/kinosearch

On Aug 17, 2007, at 10:14 AM, Scott Beck wrote:

> Is there a reason it isn't possible to create a new
IndexReader on an
> empty index?

There are two scenarios that could be described as
"empty index".

The first is the one that is likely to be an incorrectly
specified  
filepath: either the directory exists but there aren't any
index  
files in it, or the index directory doesn't exist.  Trying
to create  
an IndexReader against such a filepath should throw an
exception, in  
keeping with the anti-typo parameter validation strategy
deployed  
throughout the KS code base.

The second is that index files are present, but no documents
have  
been added.  In this case, the behavior ought to be an empty
but  
valid IndexReader.  However, that is not currently the case.
 This  
code produces an error:

     my $invindexer = KinoSearch::InvIndexer->new(
         invindex =>
USConSchema->clobber('dummy_index') );
     $invindexer->finish;

     my $reader = KinoSearch::Index::IndexReader->open(
         invindex => USConSchema->open('dummy_index')
);
     print "Max doc: " . $reader->max_doc .
"n";

The problem is that InvIndexer->finish declines to change
the index  
if nothing has happened, so we end up with only the starter
file and  
not a complete set of index files.  I believe this is the
error you  
encountered, based on the line number you reported.

If that were fixed, would it solve your current problem?

> Also, on a side note, the docs here:
> http://www.rectangular.com/kinosearch/docs/dev
el/KinoSearch/Store/ 
> LockFactory.html
> say to use KinoSearch::Index::IndexReader->new(),
not ->open(), but
> that gives an error.

Thank you for catching that.  Fixed by revision 2494.

Marvin Humphrey
Rectangular Research
http://www.rectangular.co
m/



_______________________________________________
KinoSearch mailing list
KinoSearchrectangular.com
http://www.rectangular.com/mailman/listinfo/kinosearch

Hi Marvin,

On 8/19/07, Marvin Humphrey <marvinrectangular.com> wrote:
>
> On Aug 17, 2007, at 10:14 AM, Scott Beck wrote:
>
> > Is there a reason it isn't possible to create a
new IndexReader on an
> > empty index?
>
> The problem is that InvIndexer->finish declines to
change the index
> if nothing has happened, so we end up with only the
starter file and
> not a complete set of index files.  I believe this is
the error you
> encountered, based on the line number you reported.
>

I believe this is the case. The only file that exists in the
index directory is:
segments_1.yaml

> If that were fixed, would it solve your current
problem?
>

I tried commenting out the error checking in IndexReader.pm
line 106
and it did fix the issue I'm having.

Thanks,

Scott

_______________________________________________
KinoSearch mailing list
KinoSearchrectangular.com
http://www.rectangular.com/mailman/listinfo/kinosearch