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// 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).
#include "utilities/merge_operators/sortlist.h"
#include "rocksdb/merge_operator.h"
#include "rocksdb/slice.h"
#include "utilities/merge_operators.h"
using ROCKSDB_NAMESPACE::Logger;
using ROCKSDB_NAMESPACE::MergeOperator;
using ROCKSDB_NAMESPACE::Slice;
namespace ROCKSDB_NAMESPACE {
bool SortList::FullMergeV2(const MergeOperationInput& merge_in,
MergeOperationOutput* merge_out) const {
std::vector<int> left;
for (Slice slice : merge_in.operand_list) {
std::vector<int> right;
MakeVector(right, slice);
left = Merge(left, right);
}
for (int i = 0; i < static_cast<int>(left.size()) - 1; i++) {
merge_out->new_value.append(std::to_string(left[i])).append(",");
}
merge_out->new_value.append(std::to_string(left.back()));
return true;
}
bool SortList::PartialMerge(const Slice& /*key*/, const Slice& left_operand,
const Slice& right_operand, std::string* new_value,
Logger* /*logger*/) const {
std::vector<int> left;
std::vector<int> right;
MakeVector(left, left_operand);
MakeVector(right, right_operand);
left = Merge(left, right);
for (int i = 0; i < static_cast<int>(left.size()) - 1; i++) {
new_value->append(std::to_string(left[i])).append(",");
}
new_value->append(std::to_string(left.back()));
return true;
}
bool SortList::PartialMergeMulti(const Slice& /*key*/,
const std::deque<Slice>& operand_list,
std::string* new_value,
Logger* /*logger*/) const {
(void)operand_list;
(void)new_value;
return true;
}
const char* SortList::Name() const { return "MergeSortOperator"; }
void SortList::MakeVector(std::vector<int>& operand, Slice slice) const {
do {
const char* begin = slice.data_;
while (*slice.data_ != ',' && *slice.data_) slice.data_++;
operand.push_back(std::stoi(std::string(begin, slice.data_)));
} while (0 != *slice.data_++);
}
std::vector<int> SortList::Merge(std::vector<int>& left,
std::vector<int>& right) const {
// Fill the resultant vector with sorted results from both vectors
std::vector<int> result;
unsigned left_it = 0, right_it = 0;
while (left_it < left.size() && right_it < right.size()) {
// If the left value is smaller than the right it goes next
// into the resultant vector
if (left[left_it] < right[right_it]) {
result.push_back(left[left_it]);
left_it++;
} else {
result.push_back(right[right_it]);
right_it++;
}
}
// Push the remaining data from both vectors onto the resultant
while (left_it < left.size()) {
result.push_back(left[left_it]);
left_it++;
}
while (right_it < right.size()) {
result.push_back(right[right_it]);
right_it++;
}
return result;
}
std::shared_ptr<MergeOperator> MergeOperators::CreateSortOperator() {
return std::make_shared<SortList>();
}
} // namespace ROCKSDB_NAMESPACE
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