rocksdb/table/iter_heap.h
Dhruba Borthakur 1186192ed1 Replace include/leveldb with include/rocksdb.
Summary: Replace include/leveldb with include/rocksdb.

Test Plan:
make clean; make check
make clean; make release

Differential Revision: https://reviews.facebook.net/D12489
2013-08-23 10:51:00 -07:00

64 lines
1.7 KiB
C++

// Copyright 2008-present Facebook. All Rights Reserved.
#ifndef STORAGE_LEVELDB_ITER_HEAP_H_
#define STORAGE_LEVELDB_ITER_HEAP_H_
#include <queue>
#include "rocksdb/comparator.h"
#include "table/iterator_wrapper.h"
namespace leveldb {
// Return the max of two keys.
class MaxIteratorComparator {
public:
MaxIteratorComparator(const Comparator* comparator) :
comparator_(comparator) {}
bool operator()(IteratorWrapper* a, IteratorWrapper* b) {
return comparator_->Compare(a->key(), b->key()) <= 0;
}
private:
const Comparator* comparator_;
};
// Return the max of two keys.
class MinIteratorComparator {
public:
// if maxHeap is set comparator returns the max value.
// else returns the min Value.
// Can use to create a minHeap or a maxHeap.
MinIteratorComparator(const Comparator* comparator) :
comparator_(comparator) {}
bool operator()(IteratorWrapper* a, IteratorWrapper* b) {
return comparator_->Compare(a->key(), b->key()) > 0;
}
private:
const Comparator* comparator_;
};
typedef std::priority_queue<
IteratorWrapper*,
std::vector<IteratorWrapper*>,
MaxIteratorComparator> MaxIterHeap;
typedef std::priority_queue<
IteratorWrapper*,
std::vector<IteratorWrapper*>,
MinIteratorComparator> MinIterHeap;
// Return's a new MaxHeap of IteratorWrapper's using the provided Comparator.
MaxIterHeap NewMaxIterHeap(const Comparator* comparator) {
return MaxIterHeap(MaxIteratorComparator(comparator));
}
// Return's a new MinHeap of IteratorWrapper's using the provided Comparator.
MinIterHeap NewMinIterHeap(const Comparator* comparator) {
return MinIterHeap(MinIteratorComparator(comparator));
}
} // namespace leveldb
#endif // STORAGE_LEVELDB_ITER_HEAP_H_