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