1 // Copyright (c) 2011-present, Facebook, Inc. All rights reserved. 2 // This source code is licensed under both the GPLv2 (found in the 3 // COPYING file in the root directory) and Apache 2.0 License 4 // (found in the LICENSE.Apache file in the root directory). 5 // Copyright (c) 2011 The LevelDB Authors. All rights reserved. 6 // Use of this source code is governed by a BSD-style license that can be 7 // found in the LICENSE file. See the AUTHORS file for names of contributors. 8 9 #pragma once 10 11 #include "monitoring/perf_context_imp.h" 12 #include "rocksdb/comparator.h" 13 14 namespace ROCKSDB_NAMESPACE { 15 16 // Wrapper of user comparator, with auto increment to 17 // perf_context.user_key_comparison_count. 18 class UserComparatorWrapper final : public Comparator { 19 public: UserComparatorWrapper(const Comparator * const user_cmp)20 explicit UserComparatorWrapper(const Comparator* const user_cmp) 21 : user_comparator_(user_cmp) {} 22 23 ~UserComparatorWrapper() = default; 24 user_comparator()25 const Comparator* user_comparator() const { return user_comparator_; } 26 Compare(const Slice & a,const Slice & b)27 int Compare(const Slice& a, const Slice& b) const override { 28 PERF_COUNTER_ADD(user_key_comparison_count, 1); 29 return user_comparator_->Compare(a, b); 30 } 31 Equal(const Slice & a,const Slice & b)32 bool Equal(const Slice& a, const Slice& b) const override { 33 PERF_COUNTER_ADD(user_key_comparison_count, 1); 34 return user_comparator_->Equal(a, b); 35 } 36 Name()37 const char* Name() const override { return user_comparator_->Name(); } 38 FindShortestSeparator(std::string * start,const Slice & limit)39 void FindShortestSeparator(std::string* start, 40 const Slice& limit) const override { 41 return user_comparator_->FindShortestSeparator(start, limit); 42 } 43 FindShortSuccessor(std::string * key)44 void FindShortSuccessor(std::string* key) const override { 45 return user_comparator_->FindShortSuccessor(key); 46 } 47 GetRootComparator()48 const Comparator* GetRootComparator() const override { 49 return user_comparator_->GetRootComparator(); 50 } 51 IsSameLengthImmediateSuccessor(const Slice & s,const Slice & t)52 bool IsSameLengthImmediateSuccessor(const Slice& s, 53 const Slice& t) const override { 54 return user_comparator_->IsSameLengthImmediateSuccessor(s, t); 55 } 56 CanKeysWithDifferentByteContentsBeEqual()57 bool CanKeysWithDifferentByteContentsBeEqual() const override { 58 return user_comparator_->CanKeysWithDifferentByteContentsBeEqual(); 59 } 60 61 private: 62 const Comparator* user_comparator_; 63 }; 64 65 } // namespace ROCKSDB_NAMESPACE 66