1 // Copyright (C) 2019 Google LLC 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 #ifndef ICING_SCORING_RANKER_H_ 16 #define ICING_SCORING_RANKER_H_ 17 18 #include <vector> 19 20 #include "icing/scoring/scored-document-hit.h" 21 22 // Provides functionality to get the top N results from an unsorted vector. 23 namespace icing { 24 namespace lib { 25 26 // Builds a heap of scored document hits. The same vector is used to store the 27 // heap structure. 28 // 29 // REQUIRED: scored_document_hits is not null. 30 void BuildHeapInPlace( 31 std::vector<ScoredDocumentHit>* scored_document_hits, 32 const ScoredDocumentHitComparator& scored_document_hit_comparator); 33 34 // Returns the top num_results results from the given heap and remove those 35 // results from the heap. An empty vector will be returned if heap is empty. 36 // 37 // REQUIRED: scored_document_hits_heap is not null. 38 std::vector<ScoredDocumentHit> PopTopResultsFromHeap( 39 std::vector<ScoredDocumentHit>* scored_document_hits_heap, int num_results, 40 const ScoredDocumentHitComparator& scored_document_hit_comparator); 41 42 } // namespace lib 43 } // namespace icing 44 45 #endif // ICING_SCORING_RANKER_H_ 46