Fix bug: override the compare function of SearchResultPair (#6628)

Signed-off-by: Ndragondriver <jiquan.long@zilliz.com>

internal/core/src/segcore/ReduceStructure.h

+// Copyright (C) 2019-2020 Zilliz. All rights reserved.
+//
+// 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
+
+#include <cmath>  // std::isnan
+#include <common/Types.h>
+#include "segcore/Reduce.h"
+
+struct SearchResultPair {
+    float distance_;
+    milvus::SearchResult* search_result_;
+    int64_t offset_;
+    int64_t index_;
+
+    SearchResultPair(float distance, milvus::SearchResult* search_result, int64_t offset, int64_t index)
+        : distance_(distance), search_result_(search_result), offset_(offset), index_(index) {
+    }
+
+    bool
+    operator<(const SearchResultPair& pair) const {
+        return std::isnan(pair.distance_) || (!std::isnan(distance_) && (distance_ < pair.distance_));
+    }
+
+    bool
+    operator>(const SearchResultPair& pair) const {
+        return std::isnan(pair.distance_) || (!std::isnan(distance_) && (distance_ > pair.distance_));
+    }
+
+    void
+    reset_distance() {
+        distance_ = search_result_->result_distances_[offset_];
+    }
+};

internal/core/src/segcore/reduce_c.cpp

@@ -14,6 +14,7 @@
 #include "segcore/reduce_c.h"
 
 #include "segcore/Reduce.h"
+#include "segcore/ReduceStructure.h"
 #include "common/Types.h"
 #include "pb/milvus.pb.h"
 
@@ -49,32 +50,6 @@ DeleteMarshaledHits(CMarshaledHits c_marshaled_hits) {
     delete hits;
 }
 
-struct SearchResultPair {
-    float distance_;
-    SearchResult* search_result_;
-    int64_t offset_;
-    int64_t index_;
-
-    SearchResultPair(float distance, SearchResult* search_result, int64_t offset, int64_t index)
-        : distance_(distance), search_result_(search_result), offset_(offset), index_(index) {
-    }
-
-    bool
-    operator<(const SearchResultPair& pair) const {
-        return (distance_ < pair.distance_);
-    }
-
-    bool
-    operator>(const SearchResultPair& pair) const {
-        return (distance_ > pair.distance_);
-    }
-
-    void
-    reset_distance() {
-        distance_ = search_result_->result_distances_[offset_];
-    }
-};
-
 void
 GetResultData(std::vector<std::vector<int64_t>>& search_records,
               std::vector<SearchResult*>& search_results,

internal/core/unittest/CMakeLists.txt

@@ -37,6 +37,7 @@ set(MILVUS_TEST_FILES
         test_segcore.cpp
         test_span.cpp
         test_timestamp_index.cpp
+        test_reduce_c.cpp
         )
 
 add_executable(all_tests

internal/core/unittest/test_reduce_c.cpp

+// Copyright (C) 2019-2020 Zilliz. All rights reserved.
+//
+// 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
+
+#include <gtest/gtest.h>
+#include "segcore/ReduceStructure.h"
+
+TEST(SearchResultPair, Less) {
+    auto pair1 = SearchResultPair(1.0, nullptr, 0, 0);
+    auto pair2 = SearchResultPair(1.0, nullptr, 0, 0);
+    ASSERT_EQ(pair1 < pair2, false);
+    ASSERT_EQ(pair1.operator<(pair2), false);
+
+    pair1.distance_ = 1.0;
+    pair2.distance_ = 2.0;
+    ASSERT_EQ(pair1 < pair2, true);
+    ASSERT_EQ(pair1.operator<(pair2), true);
+
+    pair1.distance_ = 1.0;
+    pair2.distance_ = NAN;
+    ASSERT_EQ(pair1 < pair2, true);
+    ASSERT_EQ(pair1.operator<(pair2), true);
+
+    pair1.distance_ = 2.0;
+    pair2.distance_ = 1.0;
+    ASSERT_EQ(pair1 < pair2, false);
+    ASSERT_EQ(pair1.operator<(pair2), false);
+
+    pair1.distance_ = 2.0;
+    pair2.distance_ = 2.0;
+    ASSERT_EQ(pair1 < pair2, false);
+    ASSERT_EQ(pair1.operator<(pair2), false);
+
+    pair1.distance_ = 2.0;
+    pair2.distance_ = NAN;
+    ASSERT_EQ(pair1 < pair2, true);
+    ASSERT_EQ(pair1.operator<(pair2), true);
+
+    pair1.distance_ = NAN;
+    pair2.distance_ = 1.0;
+    ASSERT_EQ(pair1 < pair2, false);
+    ASSERT_EQ(pair1.operator<(pair2), false);
+
+    pair1.distance_ = NAN;
+    pair2.distance_ = 2.0;
+    ASSERT_EQ(pair1 < pair2, false);
+    ASSERT_EQ(pair1.operator<(pair2), false);
+
+    pair1.distance_ = NAN;
+    pair2.distance_ = NAN;
+    ASSERT_EQ(pair1 < pair2, true);
+    ASSERT_EQ(pair1.operator<(pair2), true);
+}
+
+TEST(SearchResultPair, Greater) {
+    auto pair1 = SearchResultPair(1.0, nullptr, 0, 0);
+    auto pair2 = SearchResultPair(1.0, nullptr, 0, 0);
+    ASSERT_EQ(pair1 > pair2, false);
+    ASSERT_EQ(pair1.operator>(pair2), false);
+
+    pair1.distance_ = 1.0;
+    pair2.distance_ = 2.0;
+    ASSERT_EQ(pair1 > pair2, false);
+    ASSERT_EQ(pair1.operator>(pair2), false);
+
+    pair1.distance_ = 1.0;
+    pair2.distance_ = NAN;
+    ASSERT_EQ(pair1 > pair2, true);
+    ASSERT_EQ(pair1.operator>(pair2), true);
+
+    pair1.distance_ = 2.0;
+    pair2.distance_ = 1.0;
+    ASSERT_EQ(pair1 > pair2, true);
+    ASSERT_EQ(pair1.operator>(pair2), true);
+
+    pair1.distance_ = 2.0;
+    pair2.distance_ = 2.0;
+    ASSERT_EQ(pair1 > pair2, false);
+    ASSERT_EQ(pair1.operator>(pair2), false);
+
+    pair1.distance_ = 2.0;
+    pair2.distance_ = NAN;
+    ASSERT_EQ(pair1 > pair2, true);
+    ASSERT_EQ(pair1.operator>(pair2), true);
+
+    pair1.distance_ = NAN;
+    pair2.distance_ = 1.0;
+    ASSERT_EQ(pair1 > pair2, false);
+    ASSERT_EQ(pair1.operator>(pair2), false);
+
+    pair1.distance_ = NAN;
+    pair2.distance_ = 2.0;
+    ASSERT_EQ(pair1 > pair2, false);
+    ASSERT_EQ(pair1.operator>(pair2), false);
+
+    pair1.distance_ = NAN;
+    pair2.distance_ = NAN;
+    ASSERT_EQ(pair1 > pair2, true);
+    ASSERT_EQ(pair1.operator>(pair2), true);
+}