/// <summary>
/// Returns the <see cref="PassageFormatter"/> to use for
/// formatting passages into highlighted snippets. This
/// returns a new <see cref="PassageFormatter"/> by default;
/// subclasses can override to customize.
/// </summary>
protected virtual PassageFormatter GetFormatter(string field)
{
if (defaultFormatter is null)
{
defaultFormatter = new DefaultPassageFormatter();
}
return(defaultFormatter);
}
public PostingsHighlighterAnalyzerAndFormatterHelper(Analyzer analyzer, PassageFormatter formatter)
: base(analyzer)
{
this.formatter = formatter;
}
private IDictionary <int, object> HighlightField(string field, string[] contents, BreakIterator bi, BytesRef[] terms, int[] docids, IList <AtomicReaderContext> leaves, int maxPassages, Query query)
{
IDictionary <int, object> highlights = new Dictionary <int, object>();
PassageFormatter fieldFormatter = GetFormatter(field);
if (fieldFormatter is null)
{
// LUCENENET: Changed from NullPointerException to InvalidOperationException (which isn't caught anywhere outside of tests)
throw IllegalStateException.Create("PassageFormatter cannot be null");
}
// check if we should do any multiterm processing
Analyzer analyzer = GetIndexAnalyzer(field);
CharacterRunAutomaton[] automata = Arrays.Empty <CharacterRunAutomaton>();
if (analyzer != null)
{
automata = MultiTermHighlighting.ExtractAutomata(query, field);
}
// resize 'terms', where the last term is the multiterm matcher
if (automata.Length > 0)
{
BytesRef[] newTerms = new BytesRef[terms.Length + 1];
System.Array.Copy(terms, 0, newTerms, 0, terms.Length);
terms = newTerms;
}
// we are processing in increasing docid order, so we only need to reinitialize stuff on segment changes
// otherwise, we will just advance() existing enums to the new document in the same segment.
DocsAndPositionsEnum[] postings = null;
TermsEnum termsEnum = null;
int lastLeaf = -1;
for (int i = 0; i < docids.Length; i++)
{
string content = contents[i];
if (content.Length == 0)
{
continue; // nothing to do
}
bi.SetText(content);
int doc = docids[i];
int leaf = ReaderUtil.SubIndex(doc, leaves);
AtomicReaderContext subContext = leaves[leaf];
AtomicReader r = subContext.AtomicReader;
if (Debugging.AssertsEnabled)
{
Debugging.Assert(leaf >= lastLeaf); // increasing order
}
// if the segment has changed, we must initialize new enums.
if (leaf != lastLeaf)
{
Terms t = r.GetTerms(field);
if (t != null)
{
termsEnum = t.GetEnumerator();
postings = new DocsAndPositionsEnum[terms.Length];
}
}
if (termsEnum is null)
{
continue; // no terms for this field, nothing to do
}
// if there are multi-term matches, we have to initialize the "fake" enum for each document
if (automata.Length > 0)
{
DocsAndPositionsEnum dp = MultiTermHighlighting.GetDocsEnum(analyzer.GetTokenStream(field, content), automata);
dp.Advance(doc - subContext.DocBase);
postings[terms.Length - 1] = dp; // last term is the multiterm matcher
}
Passage[] passages = HighlightDoc(field, terms, content.Length, bi, doc - subContext.DocBase, termsEnum, postings, maxPassages);
if (passages.Length == 0)
{
// no passages were returned, so ask for a default summary
passages = GetEmptyHighlight(field, bi, maxPassages);
}
if (passages.Length > 0)
{
highlights[doc] = fieldFormatter.Format(passages, content);
}
lastLeaf = leaf;
}
return(highlights);
}
