// Copyright (c) 2018-2025 Benoit Chesneau
//
// This file is provided to you under the Apache License,
// Version 2.0 (the "License"); you may not use this file
// except in compliance with the License.  You may obtain
// a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied.  See the License for the
// specific language governing permissions and limitations
// under the License.


#pragma once
#include "rocksdb/merge_operator.h"
#include "rocksdb/slice.h"

// forward declaation
namespace rocksdb {
    class AssociativeMergeOperator;
}

namespace erocksdb {

    class CounterMergeOperator : public rocksdb::AssociativeMergeOperator {

        public:
            explicit CounterMergeOperator();

            virtual bool Merge(
                    const rocksdb::Slice& key,
                    const rocksdb::Slice* existing_value,
                    const rocksdb::Slice& value,
                    std::string* new_value,
                    rocksdb::Logger* logger) const override;

            virtual const char* Name() const override;
    };

    std::shared_ptr<CounterMergeOperator> CreateCounterMergeOperator();

}