@Test
public void testGetSortType() {
  SearchImpl search = new SearchImpl(reader);

  assertFalse(search.getSortType("f1", "STRING", false).isPresent());

  assertEquals(new SortField("f2", SortField.Type.STRING, false),
      search.getSortType("f2", "STRING", false).get());
  assertFalse(search.getSortType("f2", "INT", false).isPresent());

  assertEquals(new SortedSetSortField("f3", false),
      search.getSortType("f3", "CUSTOM", false).get());

  assertEquals(new SortField("f4", SortField.Type.LONG, false),
      search.getSortType("f4", "LONG", false).get());
  assertFalse(search.getSortType("f4", "STRING", false).isPresent());

  assertEquals(new SortField("f5", SortField.Type.FLOAT, false),
      search.getSortType("f5", "FLOAT", false).get());
  assertFalse(search.getSortType("f5", "STRING", false).isPresent());

  assertEquals(new SortField("f6", SortField.Type.DOUBLE, false),
      search.getSortType("f6", "DOUBLE", false).get());
  assertFalse(search.getSortType("f6", "STRING", false).isPresent());

  assertEquals(new SortedNumericSortField("f7", SortField.Type.LONG, false),
      search.getSortType("f7", "LONG", false).get());
  assertFalse(search.getSortType("f7", "STRING", false).isPresent());
}
 

public void testWrongSortFieldType() throws Exception {
  Directory dir = newDirectory();
  List<Field> dvs = new ArrayList<>();
  dvs.add(new SortedDocValuesField("field", new BytesRef("")));
  dvs.add(new SortedSetDocValuesField("field", new BytesRef("")));
  dvs.add(new NumericDocValuesField("field", 42));
  dvs.add(new SortedNumericDocValuesField("field", 42));

  List<SortField> sortFields = new ArrayList<>();
  sortFields.add(new SortField("field", SortField.Type.STRING));
  sortFields.add(new SortedSetSortField("field", false));
  sortFields.add(new SortField("field", SortField.Type.INT));
  sortFields.add(new SortedNumericSortField("field", SortField.Type.INT));

  for (int i = 0; i < sortFields.size(); i++) {
    for (int j = 0; j < dvs.size(); j++) {
      if (i == j) {
        continue;
      }
      Sort indexSort = new Sort(sortFields.get(i));
      IndexWriterConfig iwc = new IndexWriterConfig(new MockAnalyzer(random()));
      iwc.setIndexSort(indexSort);
      IndexWriter w = new IndexWriter(dir, iwc);
      Document doc = new Document();
      doc.add(dvs.get(j));
      IllegalArgumentException exc = expectThrows(IllegalArgumentException.class, () -> w.addDocument(doc));
      assertThat(exc.getMessage(), containsString("expected field [field] to be "));
      doc.clear();
      doc.add(dvs.get(i));
      w.addDocument(doc);
      doc.add(dvs.get(j));
      exc = expectThrows(IllegalArgumentException.class, () -> w.addDocument(doc));
      assertThat(exc.getMessage(), containsString("cannot change DocValues type"));
      w.rollback();
      IOUtils.close(w);
    }
  }
  IOUtils.close(dir);
}
 

/**
 * Same as {@link #getSortField} but using {@link SortedSetSortField}
 */
protected static SortField getSortedSetSortField(SchemaField field, SortedSetSelector.Type selector,
                                                 boolean reverse, Object missingLow, Object missingHigh) {
                                                 
  field.checkSortability();
  SortField sf = new SortedSetSortField(field.getName(), reverse, selector);
  applySetMissingValue(field, sf, missingLow, missingHigh);
  
  return sf;
}
 

private static int runQuery(IndexReader indexReader, int count, Query q) throws IOException {
	long start = System.currentTimeMillis();
	IndexSearcher searcher = new IndexSearcher(indexReader);

	Sort sort = new Sort();

	sort.setSort(new SortedSetSortField("category", false));

	TopFieldCollector collector = TopFieldCollector.create(sort, count, null, true, true, true);

	searcher.search(q, collector);

	ScoreDoc[] hits = collector.topDocs().scoreDocs;
	int totalHits = collector.getTotalHits();
	@SuppressWarnings("unused") long searchTime = System.currentTimeMillis() - start;

	start = System.currentTimeMillis();

	List<String> ids = new ArrayList<>();
	for (ScoreDoc hit : hits) {
		int docId = hit.doc;
		Document d = searcher.doc(docId);
		ids.add(d.get("uid"));

	}
	@SuppressWarnings("unused") long fetchTime = System.currentTimeMillis() - start;

	return totalHits;
}
 

@Override
public List<SortField> guessSortTypes(String name) {
  FieldInfo finfo = IndexUtils.getFieldInfo(reader, name);
  if (finfo == null) {
    throw new LukeException("No such field: " + name, new IllegalArgumentException());
  }

  DocValuesType dvType = finfo.getDocValuesType();

  switch (dvType) {
    case NONE:
      return Collections.emptyList();

    case NUMERIC:
      return Arrays.stream(new SortField[]{
          new SortField(name, SortField.Type.INT),
          new SortField(name, SortField.Type.LONG),
          new SortField(name, SortField.Type.FLOAT),
          new SortField(name, SortField.Type.DOUBLE)
      }).collect(Collectors.toList());

    case SORTED_NUMERIC:
      return Arrays.stream(new SortField[]{
          new SortedNumericSortField(name, SortField.Type.INT),
          new SortedNumericSortField(name, SortField.Type.LONG),
          new SortedNumericSortField(name, SortField.Type.FLOAT),
          new SortedNumericSortField(name, SortField.Type.DOUBLE)
      }).collect(Collectors.toList());

    case SORTED:
      return Arrays.stream(new SortField[] {
          new SortField(name, SortField.Type.STRING),
          new SortField(name, SortField.Type.STRING_VAL)
      }).collect(Collectors.toList());

    case SORTED_SET:
      return Collections.singletonList(new SortedSetSortField(name, false));

    default:
      return Collections.singletonList(new SortField(name, SortField.Type.DOC));
  }

}
 

@Test
public void testGuessSortTypes() {
  SearchImpl search = new SearchImpl(reader);

  assertTrue(search.guessSortTypes("f1").isEmpty());

  assertArrayEquals(
      new SortField[]{
          new SortField("f2", SortField.Type.STRING),
          new SortField("f2", SortField.Type.STRING_VAL)},
      search.guessSortTypes("f2").toArray());

  assertArrayEquals(
      new SortField[]{new SortedSetSortField("f3", false)},
      search.guessSortTypes("f3").toArray());

  assertArrayEquals(
      new SortField[]{
          new SortField("f4", SortField.Type.INT),
          new SortField("f4", SortField.Type.LONG),
          new SortField("f4", SortField.Type.FLOAT),
          new SortField("f4", SortField.Type.DOUBLE)},
      search.guessSortTypes("f4").toArray());

  assertArrayEquals(
      new SortField[]{
          new SortField("f5", SortField.Type.INT),
          new SortField("f5", SortField.Type.LONG),
          new SortField("f5", SortField.Type.FLOAT),
          new SortField("f5", SortField.Type.DOUBLE)},
      search.guessSortTypes("f5").toArray());

  assertArrayEquals(
      new SortField[]{
          new SortField("f6", SortField.Type.INT),
          new SortField("f6", SortField.Type.LONG),
          new SortField("f6", SortField.Type.FLOAT),
          new SortField("f6", SortField.Type.DOUBLE)},
      search.guessSortTypes("f6").toArray());

  assertArrayEquals(
      new SortField[]{
          new SortedNumericSortField("f7", SortField.Type.INT),
          new SortedNumericSortField("f7", SortField.Type.LONG),
          new SortedNumericSortField("f7", SortField.Type.FLOAT),
          new SortedNumericSortField("f7", SortField.Type.DOUBLE)},
      search.guessSortTypes("f7").toArray());
}
 

@Override
public SortField getSortField(boolean reverse) {
  return new SortedSetSortField(this.field, reverse, this.selector);
}