Thanks Michael,
if I understand correctly the DoubleValuesSource is stateful.
When getValues is called if scores is null an internal state true/false is
saved.
This state should be returned by needsScores method.
Is this correct?
As far as I understood, the same thing happens to the DoubleValue object
returned by the getValues() method.
DoubleValue object has an internal state which depends from advanceExact()
method.
In other words, DoubleValue.doubleValue() returns a value produced after
the call of advanceExact(int docId).
Now the problem I have is understanding if DoubleValuesSource has to be
stateful or has to store an state that should be available later.
Or, on the other hand, understand if there is an order in the methods calls
(first getValues then needsScores, first advanceExact then doubleValue).
Don't you agree?
On Mon, Jul 6, 2020 at 4:58 PM Michael Sokolov <msoko...@gmail.com> wrote:
> That controls whether getValues(LeafReaderContext ctx, DoubleValues
> scores) gets a null scores parameter or not. You should say true only
> if you need the text relevance scores computed by the Query's Scorer.
>
> On Mon, Jul 6, 2020 at 10:22 AM Vincenzo D'Amore <v.dam...@gmail.com>
> wrote:
> >
> > Hi Michael, thanks for answering my questions.
> > Yes, I read, but I think that it not is enough.
> >
> > For make the things clearer, this is taken from the javadocs:
> >
> > abstract boolean needsScores() - Return true if document scores are
> needed
> > to calculate values
> >
> > So, I thought return true, because yes, I need to calculate the scores
> for
> > my custom implementations.
> > Anyway, I should remember that the wrong way always seems more reasonable
> > :) , and googling around for:
> >
> > "boolean needsScores" "DoubleValuesSource" site:github.com
> >
> > I found that when there is explicit code many implementations returns
> > directly: false.
> >
> > What does this mean? why and when should I return true or false?
> >
> >
> > On Mon, Jul 6, 2020 at 2:50 PM Michael Sokolov <msoko...@gmail.com>
> wrote:
> >
> > > Did you read the DoubleValuesSource javadocs, and find they weren't
> enough?
> > >
> > > On Sun, Jul 5, 2020 at 7:54 AM Vincenzo D'Amore <v.dam...@gmail.com>
> > > wrote:
> > > >
> > > > Hi all,
> > > >
> > > > Finally I have a custom DoubleValuesSource that gives the expected
> > > results,
> > > > but I'm a little worried about the lack of documentation.
> > > >
> > > > When you extend DoubleValuesSource there are a number of methods to
> > > write,
> > > > for some of them it is not clear what they do and why they need to be
> > > > implemented.
> > > > Here I've listed the mandatory methods:
> > > >
> > > > public abstract DoubleValues getValues(LeafReaderContext var1,
> > > > DoubleValues var2) throws IOException;
> > > > public abstract boolean needsScores()
> > > > public abstract DoubleValuesSource rewrite(IndexSearcher var1)
> throws
> > > > IOException;
> > > > public boolean isCacheable(LeafReaderContext ctx);
> > > > public abstract int hashCode();
> > > > public abstract boolean equals(Object var1);
> > > >
> > > > for some of them I could imagine why (hashCode() or equals()) but
> what
> > > > about the others?
> > > > As said, I wrote an implementation of getValues that returns the
> expected
> > > > results (I've compared the results with the old version), but for
> many
> > > > methods I've just mimed (copied) the code found in other
> implementations.
> > > > So why does needsScores() always return false, how to implement
> > > > correctly isCacheable() ?
> > > > Anyone could write a short description of these methods and how they
> > > > have to be implemented?
> > > >
> > > > Best regards,
> > > > Vincenzo
> > > >
> > > > On Sat, Jul 4, 2020 at 3:29 AM Vincenzo D'Amore <v.dam...@gmail.com>
> > > wrote:
> > > >
> > > > > Hi all, I did few steps forward but still struggling in how read
> the
> > > field
> > > > > value inside my custom DoubleValuesSource
> > > > >
> > > > > final CustomValuesSource valuesSource = new
> > > > > CustomValuesSource(data, req.getSchema().getField(field));
> > > > > return FunctionScoreQuery.boostByValue(query,
> > > > > valuesSource);
> > > > >
> > > > > CustomValuesSource extends DoubleValuesSource
> > > > >
> > > > > But, if I did right, I'm struggling with the getValues code.
> > > > >
> > > > > public DoubleValues getValues(LeafReaderContext ctx, DoubleValues
> > > scores)
> > > > > throws IOException {
> > > > >
> > > > > The field I have to read is a binary field, and I can't find an
> example
> > > > > how to read a binary field from LeafReaderContext
> > > > >
> > > > > Any help appreciated.
> > > > >
> > > > > Best regards,
> > > > > Vincenzo
> > > > >
> > > > > On Thu, Jul 2, 2020 at 1:19 PM Vincenzo D'Amore <
> v.dam...@gmail.com>
> > > > > wrote:
> > > > >
> > > > >> Hi Mikhail, I was just trying to understand how to extend
> > > > >> DoubleValuesSource class, now I'm looking around to find an
> inspiring
> > > > >> example...
> > > > >>
> > > > >> On Thu, Jul 2, 2020 at 12:55 PM Mikhail Khludnev <m...@apache.org
> >
> > > wrote:
> > > > >>
> > > > >>> Hi, Vincenzo.
> > > > >>>
> > > > >>> Have you tried to implement DoubleValuesSource ?
> > > > >>>
> > > > >>> On Thu, Jul 2, 2020 at 9:58 AM Vincenzo D'Amore <
> v.dam...@gmail.com>
> > > > >>> wrote:
> > > > >>>
> > > > >>> > Again, @Federico Pici or anybody, did you figure out how to
> > > > >>> > port CustomScoreQuery in Solr8?
> > > > >>> >
> > > > >>> > On Tue, Jul 23, 2019 at 1:05 AM Xiaofei <m...@xiaofei.ca> wrote:
> > > > >>> >
> > > > >>> > > @Federico Pici, did you figure out on how to produce
> customized
> > > > >>> score in
> > > > >>> > > Solr
> > > > >>> > > 8?
> > > > >>> > >
> > > > >>> > >
> > > > >>> > >
> > > > >>> > > --
> > > > >>> > > Sent from:
> > > > >>> > >
> > > http://lucene.472066.n3.nabble.com/Lucene-Java-Users-f532864.html
> > > > >>> > >
> > > > >>> > >
> > > ---------------------------------------------------------------------
> > > > >>> > > To unsubscribe, e-mail:
> java-user-unsubscr...@lucene.apache.org
> > > > >>> > > For additional commands, e-mail:
> > > java-user-h...@lucene.apache.org
> > > > >>> > >
> > > > >>> > >
> > > > >>> >
> > > > >>> > --
> > > > >>> > Vincenzo D'Amore
> > > > >>> >
> > > > >>>
> > > > >>>
> > > > >>> --
> > > > >>> Sincerely yours
> > > > >>> Mikhail Khludnev
> > > > >>>
> > > > >>
> > > > >>
> > > > >> --
> > > > >> Vincenzo D'Amore
> > > > >>
> > > > >>
> > > > >
> > > > > --
> > > > > Vincenzo D'Amore
> > > > >
> > > > >
> > > >
> > > > --
> > > > Vincenzo D'Amore
> > >
> > > ---------------------------------------------------------------------
> > > To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org
> > > For additional commands, e-mail: java-user-h...@lucene.apache.org
> > >
> > >
> >
> > --
> > Vincenzo D'Amore
>
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>
>
--
Vincenzo D'Amore
