Port over Icing c++ code from upstream

Change-Id: Ia3981fed7e0e70589efc027d4123f306cdfbe990

1 files changed, 67 insertions, 0 deletions

diff --git a/icing/index/iterator/doc-hit-info-iterator-section-restrict.h b/icing/index/iterator/doc-hit-info-iterator-section-restrict.h
new file mode 100644
index 0000000..f9b9b04
--- /dev/null
+++ b/icing/index/iterator/doc-hit-info-iterator-section-restrict.h
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+// 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_INDEX_ITERATOR_DOC_HIT_INFO_ITERATOR_SECTION_RESTRICT_H_
+#define ICING_INDEX_ITERATOR_DOC_HIT_INFO_ITERATOR_SECTION_RESTRICT_H_
+
+#include <cstdint>
+#include <memory>
+#include <string>
+#include <string_view>
+
+#include "utils/base/status.h"
+#include "icing/index/iterator/doc-hit-info-iterator.h"
+#include "icing/schema/schema-store.h"
+#include "icing/store/document-store.h"
+
+namespace icing {
+namespace lib {
+
+// A iterator that helps filter for DocHitInfos whose term was in a section
+// named target_section.
+//
+// NOTE: This is a little different from the DocHitInfoIteratorFilter class.
+// That class is meant to be applied to the root of a query tree and filter over
+// all results at the end. This class is more used in the limited scope of a
+// term or a small group of terms.
+class DocHitInfoIteratorSectionRestrict : public DocHitInfoIterator {
+ public:
+  // Does not take any ownership, and all pointers must refer to valid objects
+  // that outlive the one constructed.
+  explicit DocHitInfoIteratorSectionRestrict(
+      std::unique_ptr<DocHitInfoIterator> delegate,
+      const DocumentStore* document_store, const SchemaStore* schema_store,
+      std::string_view target_section);
+
+  libtextclassifier3::Status Advance() override;
+
+  int32_t GetNumBlocksInspected() const override;
+
+  int32_t GetNumLeafAdvanceCalls() const override;
+
+  std::string ToString() const override;
+
+ private:
+  std::unique_ptr<DocHitInfoIterator> delegate_;
+  const DocumentStore& document_store_;
+  const SchemaStore& schema_store_;
+
+  // Ensure that this does not outlive the underlying string value.
+  std::string_view target_section_;
+};
+
+}  // namespace lib
+}  // namespace icing
+
+#endif  // ICING_INDEX_ITERATOR_DOC_HIT_INFO_ITERATOR_SECTION_RESTRICT_H_