Examples of org.apache.lucene.search.postingshighlight.CustomPostingsHighlighter

org.apache.lucene.search.postingshighlight.CustomPostingsHighlighter

Subclass of the {@link XPostingsHighlighter} that works for a single field in a single document.It receives the field values as input and it performs discrete highlighting on each single value calling the highlightDoc method multiple times. It allows to pass in the query terms to avoid calling extract terms multiple times. The use that we make of the postings highlighter is not optimal. It would be much better to highlight multiple docs in a single call, as we actually lose its sequential IO. But that would require: 1) to make our fork more complex and harder to maintain to perform discrete highlighting (needed to return a different snippet per value when number_of_fragments=0 and the field has multiple values) 2) refactoring of the elasticsearch highlight api which currently works per hit

        int numberOfFragments;


        try {
            //we manually load the field values (from source if needed)
            List<Object> textsToHighlight = HighlightUtils.loadFieldValues(field, fieldMapper, context, hitContext);
            CustomPostingsHighlighter highlighter = new CustomPostingsHighlighter(mapperHighlighterEntry.passageFormatter, textsToHighlight, mergeValues, Integer.MAX_VALUE-1, field.fieldOptions().noMatchSize());


             if (field.fieldOptions().numberOfFragments() == 0) {
                highlighter.setBreakIterator(new WholeBreakIterator());
                numberOfFragments = 1; //1 per value since we highlight per value
            } else {
                numberOfFragments = field.fieldOptions().numberOfFragments();
            }


            //we highlight every value separately calling the highlight method multiple times, only if we need to have back a snippet per value (whole value)
            int values = mergeValues ? 1 : textsToHighlight.size();
            for (int i = 0; i < values; i++) {
                Snippet[] fieldSnippets = highlighter.highlightDoc(fieldMapper.names().indexName(), mapperHighlighterEntry.filteredQueryTerms, hitContext.searcher(), hitContext.docId(), numberOfFragments);
                if (fieldSnippets != null) {
                    for (Snippet fieldSnippet : fieldSnippets) {
                        if (Strings.hasText(fieldSnippet.getText())) {
                            snippets.add(fieldSnippet);
                        }

Examples of org.apache.lucene.search.postingshighlight.CustomPostingsHighlighter

Related Classes of org.apache.lucene.search.postingshighlight.CustomPostingsHighlighter