rocksdb/utilities/merge_operators/cassandra/merge_operator.cc
Chen Shen cbd825deea Create a MergeOperator for Cassandra Row Value
Summary:
This PR implements the MergeOperator for Cassandra Row Values.
Closes https://github.com/facebook/rocksdb/pull/2289

Differential Revision: D5055464

Pulled By: scv119

fbshipit-source-id: 45f276ef8cbc4704279202f6a20c64889bc1adef
2017-06-16 14:27:00 -07:00

104 lines
3.5 KiB
C++

// Copyright (c) 2017-present, Facebook, Inc. All rights reserved.
// This source code is licensed under the BSD-style license found in the
// LICENSE file in the root directory of this source tree. An additional grant
// of patent rights can be found in the PATENTS file in the same directory.
// This source code is also licensed under the GPLv2 license found in the
// COPYING file in the root directory of this source tree.
#include "merge_operator.h"
#include <memory>
#include <assert.h>
#include "rocksdb/slice.h"
#include "rocksdb/merge_operator.h"
#include "utilities/merge_operators.h"
#include "utilities/merge_operators/cassandra/format.h"
namespace rocksdb {
namespace cassandra {
// Implementation for the merge operation (merges two Cassandra values)
bool CassandraValueMergeOperator::FullMergeV2(
const MergeOperationInput& merge_in,
MergeOperationOutput* merge_out) const {
// Clear the *new_value for writing.
merge_out->new_value.clear();
if (merge_in.existing_value == nullptr && merge_in.operand_list.size() == 1) {
// Only one operand
merge_out->existing_operand = merge_in.operand_list.back();
return true;
}
std::vector<RowValue> row_values;
if (merge_in.existing_value) {
row_values.push_back(
RowValue::Deserialize(merge_in.existing_value->data(),
merge_in.existing_value->size()));
}
for (auto& operand : merge_in.operand_list) {
row_values.push_back(RowValue::Deserialize(operand.data(), operand.size()));
}
RowValue merged = RowValue::Merge(std::move(row_values));
merge_out->new_value.reserve(merged.Size());
merged.Serialize(&(merge_out->new_value));
return true;
}
// Implementation for the merge operation (merges two Cassandra values)
bool CassandraValueMergeOperator::PartialMerge(const Slice& key,
const Slice& left_operand,
const Slice& right_operand,
std::string* new_value,
Logger* logger) const {
// Clear the *new_value for writing.
assert(new_value);
new_value->clear();
std::vector<RowValue> row_values;
row_values.push_back(RowValue::Deserialize(left_operand.data(),
left_operand.size()));
row_values.push_back(RowValue::Deserialize(right_operand.data(),
right_operand.size()));
RowValue merged = RowValue::Merge(std::move(row_values));
new_value->reserve(merged.Size());
merged.Serialize(new_value);
return true;
}
bool CassandraValueMergeOperator::PartialMergeMulti(
const Slice& key,
const std::deque<Slice>& operand_list,
std::string* new_value,
Logger* logger) const {
// Clear the *new_value for writing.
assert(new_value);
new_value->clear();
std::vector<RowValue> row_values;
for (auto& operand : operand_list) {
row_values.push_back(RowValue::Deserialize(operand.data(), operand.size()));
}
RowValue merged = RowValue::Merge(std::move(row_values));
new_value->reserve(merged.Size());
merged.Serialize(new_value);
return true;
}
const char* CassandraValueMergeOperator::Name() const {
return "CassandraValueMergeOperator";
}
} // namespace cassandra
std::shared_ptr<MergeOperator>
MergeOperators::CreateCassandraMergeOperator() {
return std::make_shared<rocksdb::cassandra::CassandraValueMergeOperator>();
}
} // namespace rocksdb