mirror of
https://github.com/facebook/rocksdb.git
synced 2024-11-30 13:41:46 +00:00
132306fbf0
Summary: `PartialMergeMulti` implementation is enough for Cassandra, and `PartialMerge` is not required. Implementing both will just duplicate the code. As per https://github.com/facebook/rocksdb/blob/master/include/rocksdb/merge_operator.h#L130-L135 : ``` // The default implementation of PartialMergeMulti will use this function // as a helper, for backward compatibility. Any successor class of // MergeOperator should either implement PartialMerge or PartialMergeMulti, // although implementing PartialMergeMulti is suggested as it is in general // more effective to merge multiple operands at a time instead of two // operands at a time. ``` Closes https://github.com/facebook/rocksdb/pull/2737 Reviewed By: scv119 Differential Revision: D5633073 Pulled By: sagar0 fbshipit-source-id: ef4fa102c22fec6a0175ed12f5c44c15afe3c8ca
81 lines
2.3 KiB
C++
81 lines
2.3 KiB
C++
// Copyright (c) 2017-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 "merge_operator.h"
|
|
|
|
#include <memory>
|
|
#include <assert.h>
|
|
|
|
#include "rocksdb/slice.h"
|
|
#include "rocksdb/merge_operator.h"
|
|
#include "utilities/merge_operators.h"
|
|
#include "utilities/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;
|
|
}
|
|
|
|
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
|