Re: new 2.9 search API

[Artem Chereisky]

Of course, thanks for spotting it Michael. What was I thinking?!

Art

On 09/03/2010, at 15:55, Michael Garski <mgar...@myspace-inc.com> wrote:

Artem,

You're on the right track, except for step 5. The score comes directly from the Scorer.Score() method, docBase is added to the document id passed into Collect to get the overall index document number. The number passed into Collect is the number of the document in the current segment being searched.

Michael

On Mar 8, 2010, at 8:44 PM, "Artem Chereisky" <a.cherei...@gmail.com> wrote:

Thanks Michael, you pointed me in the right direction.

To answer my own question and to close the thread, I didn't need to worry about passing an instance of Scorer to MyCollector instance. The SetScorer method is called by the Searcher, so to enable scoring I needed to do 5

things:

1. have an instance of Scorer in MyCollector class
2. have an int member _docBase

      private int _docBase;
      private Scorer _scorer;

3. implement SetNextReader

      public override void SetNextReader(Lucene.Net.Index.IndexReader
reader, int docBase)
      {
          _docBase = docBase;
      }

4. Implement SetScorer

      public override void SetScorer(Scorer scorer)
      {
          _scorer = scorer;
      }

5. and finally call _scorer.Score() in Collect method adding _docBase to the

result of _scorer.Score().

Thanks,
Art

On Tue, Mar 9, 2010 at 3:11 AM, Michael Garski <mgar...@myspace-inc.com >wrote:

Artem,

The four methods on the Collector abstract class are invoked by the

searcher that is performing the search, and are up to you to implement

in your collector as is necessary.

With the change to segment-by-segment searching in 2.9, SetScorer and

SetNextReader allow the searcher to pass the current Scorer and
IndexReader to the collector.

The javadocs have the same content as the .NET documentation comments,

and the one for Collector is:
http://lucene.apache.org/java/2_9_2/api/all/org/apache/lucene/search/Col

lector.html<http://lucene.apache.org/java/2_9_2/api/all/org/apache/lucene/search/Col%0Alector.html >

Additionally, take a look at the Test project file Search \QueryUtils.cs

- there are two Collector implementations in it -
AnonymousClassCollector & AnonymousClassCollector1 that are good
examples of how to implement a concrete Collector.

Michael




-----Original Message-----
From: Artem Chereisky [mailto:a.cherei...@gmail.com]
Sent: Sunday, March 07, 2010 8:27 PM
To: lucene-net-user@lucene.apache.org
Subject: new 2.9 search API

Hi,

I'm migrating my code to 2.9 and I'm having trouble understanding the

new
search API

Here is a sample 2.4 code:

var searcher = new IndexSearcher(someReader);
searcher.SetSimilarity(new MySimilarity());

var hitCollector = new MyHitCollector();
var query = MyBuildQueryMethod();

searcher.Search(query, hitCollector);

The Collect method of MyHitCollector gets called for every matching
document
with a docId and a score based on MySimilarity implementation.

In 2.9 HitCollector is replaced with Collector with 4 abstract methods

to

implement. One of them is SetScorer(Scorer). This is where I'm getting

lost.

Where do I get an instance of scorer from? There are many, one for each query type. I think I'm missing something fundamental. Please clarify.

Regards,
Art