| // Copyright (c) 2011-present, Facebook, Inc. All rights reserved. |
| // This source code is licensed under both the GPLv2 (found in the |
| // COPYING file in the root directory) and Apache 2.0 License |
| // (found in the LICENSE.Apache file in the root directory). |
| // |
| |
| #pragma once |
| |
| #include "rocksdb/comparator.h" |
| #include "table/iterator_wrapper.h" |
| |
| namespace rocksdb { |
| |
| // When used with std::priority_queue, this comparison functor puts the |
| // iterator with the max/largest key on top. |
| class MaxIteratorComparator { |
| public: |
| MaxIteratorComparator(const Comparator* comparator) : |
| comparator_(comparator) {} |
| |
| bool operator()(IteratorWrapper* a, IteratorWrapper* b) const { |
| return comparator_->Compare(a->key(), b->key()) < 0; |
| } |
| private: |
| const Comparator* comparator_; |
| }; |
| |
| // When used with std::priority_queue, this comparison functor puts the |
| // iterator with the min/smallest key on top. |
| class MinIteratorComparator { |
| public: |
| MinIteratorComparator(const Comparator* comparator) : |
| comparator_(comparator) {} |
| |
| bool operator()(IteratorWrapper* a, IteratorWrapper* b) const { |
| return comparator_->Compare(a->key(), b->key()) > 0; |
| } |
| private: |
| const Comparator* comparator_; |
| }; |
| |
| } // namespace rocksdb |