package org.apache.solr.search.function;
import org.apache.lucene.index.*;
import org.apache.lucene.search.DocIdSetIterator;
import org.apache.lucene.search.Searcher;
import org.apache.lucene.search.Similarity;
import org.apache.lucene.util.BytesRef;
import org.apache.solr.common.SolrException;
import java.io.IOException;
import java.util.Map;
public class TFValueSource extends TermFreqValueSource {
public TFValueSource(String field, String val, String indexedField, BytesRef indexedBytes) {
super(field, val, indexedField, indexedBytes);
}
@Override
public String name() {
return "tf";
}
@Override
public DocValues getValues(Map context, IndexReader reader) throws IOException {
// use MultiFields, just in case someone did a top() function
Fields fields = MultiFields.getFields(reader);
final Terms terms = fields.terms(field);
final Similarity similarity = ((Searcher)context.get("searcher")).getSimilarity();
return new FloatDocValues(this) {
DocsEnum docs ;
int atDoc;
int lastDocRequested = -1;
{ reset(); }
public void reset() throws IOException {
// no one should call us for deleted docs?
docs = terms.docs(null, indexedBytes, null);
if (docs == null) {
docs = new DocsEnum() {
@Override
public int freq() {
return 0;
}
@Override
public int docID() {
return DocIdSetIterator.NO_MORE_DOCS;
}
@Override
public int nextDoc() throws IOException {
return DocIdSetIterator.NO_MORE_DOCS;
}
@Override
public int advance(int target) throws IOException {
return DocIdSetIterator.NO_MORE_DOCS;
}
};
}
atDoc = -1;
}
@Override
public float floatVal(int doc) {
try {
if (doc < lastDocRequested) {
// out-of-order access.... reset
reset();
}
lastDocRequested = doc;
if (atDoc < doc) {
atDoc = docs.advance(doc);
}
if (atDoc > doc) {
// term doesn't match this document... either because we hit the
// end, or because the next doc is after this doc.
return similarity.tf(0);
}
// a match!
return similarity.tf(docs.freq());
} catch (IOException e) {
throw new SolrException(SolrException.ErrorCode.SERVER_ERROR, "caught exception in function "+description()+" : doc="+doc, e);
}
}
};
}
}