icing/index/string-section-indexing-handler.h

// Copyright (C) 2022 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#ifndef ICING_INDEX_STRING_SECTION_INDEXING_HANDLER_H_
#define ICING_INDEX_STRING_SECTION_INDEXING_HANDLER_H_

#include <memory>

#include "icing/text_classifier/lib3/utils/base/status.h"
#include "icing/text_classifier/lib3/utils/base/statusor.h"
#include "icing/index/index.h"
#include "icing/proto/logging.pb.h"
#include "icing/store/document-id.h"
#include "icing/transform/normalizer.h"
#include "icing/util/tokenized-document.h"

namespace icing {
namespace lib {

// This class is meant to be owned by TermIndexingHandler. Instead of using this
// handler directly, callers should use TermIndexingHandler to index documents.
//
// This handler will not check or set last_added_document_id of the index, and
// it will not merge or sort the lite index either.
class StringSectionIndexingHandler {
 public:
  // Creates a StringSectionIndexingHandler instance which does not take
  // ownership of any input components. All pointers must refer to valid objects
  // that outlive the created StringSectionIndexingHandler instance.
  //
  // Returns:
  //   - A StringSectionIndexingHandler instance on success
  //   - FAILED_PRECONDITION_ERROR if any of the input pointer is null
  static libtextclassifier3::StatusOr<
      std::unique_ptr<StringSectionIndexingHandler>>
  Create(const Normalizer* normalizer, Index* index);

  ~StringSectionIndexingHandler() = default;

  // Handles the string term indexing process: add hits into the lite index for
  // all contents in tokenized_document.tokenized_string_sections and merge lite
  // index into main index if necessary.
  //
  /// Returns:
  //   - OK on success
  //   - RESOURCE_EXHAUSTED_ERROR if the index is full and can't add anymore
  //     content.
  //   - INTERNAL_ERROR if any other errors occur.
  //   - Any main/lite index errors.
  libtextclassifier3::Status Handle(const TokenizedDocument& tokenized_document,
                                    DocumentId document_id,
                                    PutDocumentStatsProto* put_document_stats);

 private:
  explicit StringSectionIndexingHandler(const Normalizer* normalizer,
                                        Index* index)
      : normalizer_(*normalizer), index_(*index) {}

  const Normalizer& normalizer_;  // Does not own.
  Index& index_;                  // Does not own.
};

}  // namespace lib
}  // namespace icing

#endif  // ICING_INDEX_STRING_SECTION_INDEXING_HANDLER_H_