rocksdb/utilities/agg_merge/agg_merge.h

50 lines
1.8 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).
#pragma once
#include <algorithm>
#include <cstddef>
#include <memory>
#include <unordered_map>
#include "rocksdb/merge_operator.h"
#include "rocksdb/slice.h"
#include "rocksdb/utilities/agg_merge.h"
#include "utilities/cassandra/cassandra_options.h"
namespace ROCKSDB_NAMESPACE {
class AggMergeOperator : public MergeOperator {
public:
explicit AggMergeOperator();
bool FullMergeV2(const MergeOperationInput& merge_in,
MergeOperationOutput* merge_out) const override;
bool PartialMergeMulti(const Slice& key,
const std::deque<Slice>& operand_list,
std::string* new_value, Logger* logger) const override;
const char* Name() const override { return kClassName(); }
static const char* kClassName() { return "AggMergeOperator.v1"; }
bool AllowSingleOperand() const override { return true; }
bool ShouldMerge(const std::vector<Slice>&) const override { return false; }
private:
class Accumulator;
// Pack all merge operands into one value. This is called when aggregation
// fails. The existing values are preserved and returned so that users can
// debug the problem.
static void PackAllMergeOperands(const MergeOperationInput& merge_in,
MergeOperationOutput& merge_out);
static Accumulator& GetTLSAccumulator();
};
extern std::string EncodeAggFuncAndPayloadNoCheck(const Slice& function_name,
const Slice& value);
} // namespace ROCKSDB_NAMESPACE