rocksdb/table/iter_heap.h

43 lines
1.3 KiB
C
Raw Permalink Normal View History

// 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 "db/dbformat.h"
#include "table/iterator_wrapper.h"
namespace ROCKSDB_NAMESPACE {
// When used with std::priority_queue, this comparison functor puts the
// iterator with the max/largest key on top.
class MaxIteratorComparator {
public:
MaxIteratorComparator(const InternalKeyComparator* comparator)
: comparator_(comparator) {}
bool operator()(IteratorWrapper* a, IteratorWrapper* b) const {
return comparator_->Compare(a->key(), b->key()) < 0;
}
private:
const InternalKeyComparator* 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 InternalKeyComparator* comparator)
: comparator_(comparator) {}
bool operator()(IteratorWrapper* a, IteratorWrapper* b) const {
return comparator_->Compare(a->key(), b->key()) > 0;
}
private:
const InternalKeyComparator* comparator_;
};
} // namespace ROCKSDB_NAMESPACE