So for posterity, this what I ended up doing is below. But I have a
problem I don't understand; when I use fl=*,hitcount(), I get the
results I expect, but when I use fl=*,hitcount(),hitcount('fulltext_t'),
I get an NPE in Solr. This is with Solr 4.2.0. Is there a known bug? I
googled a bit but couldn't find any reference to it.
Caused by: java.lang.RuntimeException: java.lang.NullPointerException
at
org.apache.solr.response.BinaryResponseWriter.getParsedResponse(BinaryResponseWriter.java:252)
at
org.apache.solr.client.solrj.embedded.EmbeddedSolrServer.getParsedResponse(EmbeddedSolrServer.java:241)
at
org.apache.solr.client.solrj.embedded.EmbeddedSolrServer.request(EmbeddedSolrServer.java:213)
... 37 more
Caused by: java.lang.NullPointerException
at
org.apache.lucene.queries.function.valuesource.MultiFloatFunction.createWeight(MultiFloatFunction.java:95)
at
org.apache.solr.response.transform.ValueSourceAugmenter.setContext(ValueSourceAugmenter.java:71)
at
org.apache.solr.response.transform.DocTransformers.setContext(DocTransformers.java:70)
at
org.apache.solr.response.BinaryResponseWriter$Resolver.writeResultsBody(BinaryResponseWriter.java:139)
at
org.apache.solr.response.BinaryResponseWriter$Resolver.writeResults(BinaryResponseWriter.java:173)
at
org.apache.solr.response.BinaryResponseWriter$Resolver.resolve(BinaryResponseWriter.java:86)
at
org.apache.solr.common.util.JavaBinCodec.writeVal(JavaBinCodec.java:154)
at
org.apache.solr.common.util.JavaBinCodec.writeNamedList(JavaBinCodec.java:144)
at
org.apache.solr.common.util.JavaBinCodec.writeKnownType(JavaBinCodec.java:234)
at
org.apache.solr.common.util.JavaBinCodec.writeVal(JavaBinCodec.java:149)
at
org.apache.solr.common.util.JavaBinCodec.marshal(JavaBinCodec.java:92)
at
org.apache.solr.response.BinaryResponseWriter.getParsedResponse(BinaryResponseWriter.java:246)
... 39 more
/**
* Defines the Solr function hitcount([field, ...]) which returns the
total
* of termfreq(term) for all terms in the query. The argument specify
* fields whose terms are to be counted. If no arguments are passed, terms
* from every field are counted.
*/
public class HitCount extends ValueSourceParser {
@Override
public ValueSource parse(FunctionQParser fp) throws SyntaxError {
HashSet<String> fields = new HashSet<String>();
while (fp.hasMoreArguments()) {
fields.add(fp.parseArg());
}
Query q = fp.subQuery(fp.getParams().get("q"),
"lucene").getQuery();
HashSet<Term> terms = new HashSet<Term>();
q.extractTerms(terms);
ValueSource[] termcounts = new ValueSource[terms.size()];
int i = 0;
for (Term t : terms) {
if (fields.isEmpty() || fields.contains (t.field())) {
termcounts[i++] = new TermFreqValueSource(t.field(),
t.text(), t.field(), t.bytes());
}
}
return new SumFloatFunction(termcounts);
}
}
On 11/18/13 2:19 PM, Michael Sokolov wrote:
OK -- I did find SOLR-1298
<https://issues.apache.org/jira/browse/SOLR-1298>which explains how to
request the function as a field value. Still looking for a function
that does what I asked for ...
On 11/18/2013 11:55 AM, Michael Sokolov wrote:
Some of our customers want to display a "number of matches" score
next to each search result. I think what they want is to list the
number of matches that will be displayed when the entire document is
highlighted. But this can be slow to do for every search result
(some documents can be very large), so what we'd like to do is to
count the number of terms that match the query for each document, and
display that.
It looks like Solr's function query has some support for this - I see
the termfreq function, for example. My question is:
1. Is it possible to execute the query as usual, retrieving document
stored field values, and also to run a function, and return the
result as the value of a computed "pseudo-field"?
2. Is there an existing function known to the function query parser
that counts the total number of occurrences of all terms in the query
(for the current hit document)?
-Mike
