rocksdb/utilities/merge_operators/put.cc
Yanqin Jin 0376869f05 Remove using namespace (#9369)
Summary:
As title.
This is part of an fb-internal task.
First, remove all `using namespace` statements if applicable.
Next, utilize multiple build platforms and see if anything is broken.
Should anything become broken, fix the compilation errors with as little extra change as possible.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9369

Test Plan:
internal build and make check
make clean && make static_lib && cd examples && make all

Reviewed By: pdillinger

Differential Revision: D33517260

Pulled By: riversand963

fbshipit-source-id: 3fc4ce6402a073421dfd9a9b2d1c79441dca7a40
2022-01-12 09:31:12 -08:00

92 lines
3.3 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 <memory>
#include "rocksdb/slice.h"
#include "rocksdb/merge_operator.h"
#include "utilities/merge_operators.h"
namespace { // anonymous namespace
using ROCKSDB_NAMESPACE::Logger;
using ROCKSDB_NAMESPACE::MergeOperator;
using ROCKSDB_NAMESPACE::Slice;
// A merge operator that mimics Put semantics
// Since this merge-operator will not be used in production,
// it is implemented as a non-associative merge operator to illustrate the
// new interface and for testing purposes. (That is, we inherit from
// the MergeOperator class rather than the AssociativeMergeOperator
// which would be simpler in this case).
//
// From the client-perspective, semantics are the same.
class PutOperator : public MergeOperator {
public:
bool FullMerge(const Slice& /*key*/, const Slice* /*existing_value*/,
const std::deque<std::string>& operand_sequence,
std::string* new_value, Logger* /*logger*/) const override {
// Put basically only looks at the current/latest value
assert(!operand_sequence.empty());
assert(new_value != nullptr);
new_value->assign(operand_sequence.back());
return true;
}
bool PartialMerge(const Slice& /*key*/, const Slice& /*left_operand*/,
const Slice& right_operand, std::string* new_value,
Logger* /*logger*/) const override {
new_value->assign(right_operand.data(), right_operand.size());
return true;
}
using MergeOperator::PartialMergeMulti;
bool PartialMergeMulti(const Slice& /*key*/,
const std::deque<Slice>& operand_list,
std::string* new_value,
Logger* /*logger*/) const override {
new_value->assign(operand_list.back().data(), operand_list.back().size());
return true;
}
static const char* kClassName() { return "PutOperator"; }
static const char* kNickName() { return "put_v1"; }
const char* Name() const override { return kClassName(); }
const char* NickName() const override { return kNickName(); }
};
class PutOperatorV2 : public PutOperator {
bool FullMerge(const Slice& /*key*/, const Slice* /*existing_value*/,
const std::deque<std::string>& /*operand_sequence*/,
std::string* /*new_value*/,
Logger* /*logger*/) const override {
assert(false);
return false;
}
bool FullMergeV2(const MergeOperationInput& merge_in,
MergeOperationOutput* merge_out) const override {
// Put basically only looks at the current/latest value
assert(!merge_in.operand_list.empty());
merge_out->existing_operand = merge_in.operand_list.back();
return true;
}
static const char* kNickName() { return "put"; }
const char* NickName() const override { return kNickName(); }
};
} // end of anonymous namespace
namespace ROCKSDB_NAMESPACE {
std::shared_ptr<MergeOperator> MergeOperators::CreateDeprecatedPutOperator() {
return std::make_shared<PutOperator>();
}
std::shared_ptr<MergeOperator> MergeOperators::CreatePutOperator() {
return std::make_shared<PutOperatorV2>();
}
} // namespace ROCKSDB_NAMESPACE