60 lines
1.7 KiB
C++
60 lines
1.7 KiB
C++
|
// 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 <algorithm>
|
||
|
|
#include <string>
|
||
|
|
|
||
|
|
#include "utilities/merge_operators/bytesxor.h"
|
||
|
|
|
||
|
|
namespace rocksdb {
|
||
|
|
|
||
|
|
std::shared_ptr<MergeOperator> MergeOperators::CreateBytesXOROperator() {
|
||
|
|
return std::make_shared<BytesXOROperator>();
|
||
|
|
}
|
||
|
|
|
||
|
|
bool BytesXOROperator::Merge(const Slice& key,
|
||
|
|
const Slice* existing_value,
|
||
|
|
const Slice& value,
|
||
|
|
std::string* new_value,
|
||
|
|
Logger* logger) const {
|
||
|
|
XOR(existing_value, value, new_value);
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
|
||
|
|
void BytesXOROperator::XOR(const Slice* existing_value,
|
||
|
|
const Slice& value, std::string* new_value) const {
|
||
|
|
if (!existing_value) {
|
||
|
|
new_value->clear();
|
||
|
|
new_value->assign(value.data(), value.size());
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
size_t min_size = std::min(existing_value->size(), value.size());
|
||
|
|
size_t max_size = std::max(existing_value->size(), value.size());
|
||
|
|
|
||
|
|
new_value->clear();
|
||
|
|
new_value->reserve(max_size);
|
||
|
|
|
||
|
|
const char* existing_value_data = existing_value->data();
|
||
|
|
const char* value_data = value.data();
|
||
|
|
|
||
|
|
for (size_t i = 0; i < min_size; i++) {
|
||
|
|
new_value->push_back(existing_value_data[i] ^ value_data[i]);
|
||
|
|
}
|
||
|
|
|
||
|
|
if (existing_value->size() == max_size) {
|
||
|
|
for (size_t i = min_size; i < max_size; i++) {
|
||
|
|
new_value->push_back(existing_value_data[i]);
|
||
|
|
}
|
||
|
|
} else {
|
||
|
|
assert(value.size() == max_size);
|
||
|
|
for (size_t i = min_size; i < max_size; i++) {
|
||
|
|
new_value->push_back(value_data[i]);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
} // namespace rocksdb
|