public Directory CreateIndex() { if (IsLoaded) { throw new InvalidOperationException(); } IsLoading = true; var index = new RAMDirectory(); IReadOnlyList <(string UserField, string Language)> tasks = _adapter.GetUserFields() .Where(_adapter.IsIndexedInSpellchecker) .SelectMany(f => _adapter.GetFieldLanguages(f).Select(l => (f, l))) .ToList(); TotalFields = tasks.Count; var indexedWordsByField = new Dictionary <string, HashSet <string> >(Str.Comparer); void getContentToIndex((string UserField, string Language) task) { var values = _adapter.IsStoredInSpellchecker(task.UserField, task.Language) ? GetObjectsToIndex().SelectMany(c => _adapter.GetSpellcheckerValues(c, task.UserField, task.Language)) : GetValuesCache(task.UserField, task.Language); var spellcheckerField = _adapter.GetSpellcheckerFieldIn(task.UserField, task.Language); HashSet <string> indexedWords; lock (indexedWordsByField) { if (!indexedWordsByField.TryGetValue(spellcheckerField, out indexedWords)) { indexedWords = new HashSet <string>(Str.Comparer); indexedWordsByField.Add(spellcheckerField, indexedWords); } } lock (indexedWords) foreach (string value in values) { indexedWords.Add(value); } } IndexUtils.ForEach(tasks, getContentToIndex); TotalFields = indexedWordsByField.Count; _indexedFields = 0; _spellchecker.BeginIndex(index); IndexUtils.ForEach( indexedWordsByField, indexField, suppressParallelism: true); if (_abort) { return(null); } _spellchecker.EndIndex(); IsLoading = false; IndexingProgress?.Invoke(); IsLoaded = true; return(index); }