// Licensed to the Apache Software Foundation (ASF) under one

// or more contributor license agreements.  See the NOTICE file

// distributed with this work for additional information

// regarding copyright ownership.  The ASF licenses this file

// 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 <cctz/time_zone.h>

#include <gen_cpp/Types_types.h>

#include <gen_cpp/segment_v2.pb.h>

#include <ctime>

#include <map>

#include <memory>

#include <mutex>

#include <shared_mutex>

#include <unordered_map>

#include <vector>

#include "common/status.h"

#include "exec/sink/writer/varrow_flight_result_writer.h"

#include "util/countdown_latch.h"

#include "util/hash_util.hpp"

namespace arrow {

class RecordBatch;

class Schema;

} // namespace arrow

namespace doris {

class ResultBlockBufferBase;

class PUniqueId;

class RuntimeState;

class MemTrackerLimiter;

class Thread;

class GetArrowResultBatchCtx;

class GetResultBatchCtx;

class Block;

// manage all result buffer control block in one backend. here we use uniform id `unique_id` to identify buffer slots.

// for parallel result sink, it's `instance_id`, for non-parallel sink, it's `query_id`.

class ResultBufferMgr {

public:

    ResultBufferMgr();

    ~ResultBufferMgr() = default;

    // init Result Buffer Mgr, start cancel thread

    Status init();

    void stop();

    // for non-parallel sink, use query_id. but for parallel sink, use instance id.

    Status create_sender(const TUniqueId& unique_id, int buffer_size,

                         std::shared_ptr<ResultBlockBufferBase>* sender, RuntimeState* state,

                         bool arrow_flight, std::shared_ptr<arrow::Schema> schema = nullptr);

    template <typename ResultBlockBufferType>

    Status find_buffer(const TUniqueId& unique_id, std::shared_ptr<ResultBlockBufferType>& buffer);

    // cancel

    bool cancel(const TUniqueId& unique_id, const Status& reason);

    // cancel one query at a future time.

    void cancel_at_time(time_t cancel_time, const TUniqueId& unique_id);

private:

    using BufferMap = std::unordered_map<TUniqueId, std::shared_ptr<ResultBlockBufferBase>>;

    using TimeoutMap = std::map<time_t, std::vector<TUniqueId>>;

    template <typename ResultBlockBufferType>

    std::shared_ptr<ResultBlockBufferType> _find_control_block(const TUniqueId& unique_id);

    // used to erase the buffer that fe not clears

    // when fe crush, this thread clear the buffer avoid memory leak in this backend

    void cancel_thread();

    // lock for buffer map

    std::shared_mutex _buffer_map_lock;

    // buffer block map

    BufferMap _buffer_map;

    // lock for timeout map

    std::mutex _timeout_lock;

    // map (cancel_time : query to be cancelled),

    // cancel time maybe equal, so use one list

    TimeoutMap _timeout_map;

    CountDownLatch _stop_background_threads_latch;

    std::shared_ptr<Thread> _clean_thread;

};

} // namespace doris