// 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 <gen_cpp/Types_types.h>

#include <stdint.h>

#include <time.h>

#include <map>

#include <memory>

#include <mutex>

#include <string>

#include <utility>

#include "common/status.h"

#include "util/countdown_latch.h"

namespace doris {

class ExecEnv;

class Thread;

struct ScanContext {

public:

    TUniqueId fragment_instance_id;

    TUniqueId query_id;

    int64_t offset;

    // use this access_time to clean zombie context

    time_t last_access_time;

    std::mutex _local_lock;

    std::string context_id;

    short keep_alive_min;

    ScanContext(std::string id) : context_id(std::move(id)) {}

};

class ExternalScanContextMgr {

public:

    ExternalScanContextMgr(ExecEnv* exec_env);

    ~ExternalScanContextMgr() = default;

    void stop();

    Status create_scan_context(std::shared_ptr<ScanContext>* p_context);

    Status get_scan_context(const std::string& context_id, std::shared_ptr<ScanContext>* p_context);

    Status clear_scan_context(const std::string& context_id);

private:

    ExecEnv* _exec_env = nullptr;

    std::map<std::string, std::shared_ptr<ScanContext>> _active_contexts;

    void gc_expired_context();

    CountDownLatch _stop_background_threads_latch;

    std::shared_ptr<Thread> _keep_alive_reaper;

    std::mutex _lock;

};

} // namespace doris