Port over Icing c++ code from upstream

Change-Id: Ia3981fed7e0e70589efc027d4123f306cdfbe990

1 files changed, 65 insertions, 0 deletions

diff --git a/icing/scoring/scoring-processor.h b/icing/scoring/scoring-processor.h
new file mode 100644
index 0000000..b472c14
--- /dev/null
+++ b/icing/scoring/scoring-processor.h
@@ -0,0 +1,65 @@
+// Copyright (C) 2019 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_SCORING_SCORING_PROCESSOR_H_
+#define ICING_SCORING_SCORING_PROCESSOR_H_
+
+#include <memory>
+#include <utility>
+#include <vector>
+
+#include "utils/base/statusor.h"
+#include "icing/index/iterator/doc-hit-info-iterator.h"
+#include "icing/proto/scoring.pb.h"
+#include "icing/scoring/scored-document-hit.h"
+#include "icing/scoring/scorer.h"
+#include "icing/store/document-store.h"
+
+namespace icing {
+namespace lib {
+
+// ScoringProcessor is the top-level class that handles scoring.
+class ScoringProcessor {
+ public:
+  // Factory function to create a Scorer with its subcomponents according to the
+  // scoring spec.
+  //
+  // Returns:
+  //   A Scorer on success
+  //   INVALID_ARGUMENT if unable to create what the spec specifies
+  static libtextclassifier3::StatusOr<std::unique_ptr<ScoringProcessor>> Create(
+      const ScoringSpecProto& scoring_spec,
+      const DocumentStore* document_store);
+
+  // Returns a vector of ScoredDocHit sorted by their scores. The size of it is
+  // no more than num_to_return.
+  std::vector<ScoredDocumentHit> ScoreAndRank(
+      std::unique_ptr<DocHitInfoIterator> doc_hit_info_iterator,
+      int num_to_return);
+
+ private:
+  explicit ScoringProcessor(std::unique_ptr<Scorer> scorer, bool is_descending)
+      : scorer_(std::move(scorer)), is_descending_(is_descending) {}
+
+  std::unique_ptr<Scorer> scorer_;
+
+  // If true, the final result will be sorted in a descending order, otherwise
+  // ascending.
+  bool is_descending_;
+};
+
+}  // namespace lib
+}  // namespace icing
+
+#endif  // ICING_SCORING_SCORING_PROCESSOR_H_