// 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 <sys/types.h>

#include <map>

#include <set>

#include <string>

#include <vector>

#include "common/logging.h"

#include "common/status.h"

namespace doris {

// DiskInfo is an interface to query for the disk information at runtime.  This

// contains information about the system as well as the specific data node

// configuration.

// This information is pulled from /proc/partitions.

// TODO: datanode information not implemented

class DiskInfo {

public:

    // Initialize DiskInfo.  Just be called before any other functions.

    static void init();

    // Returns the number of (logical) disks on the system

    static int num_disks() {

        DCHECK(_s_initialized);

        return _s_disks.size();

    }

    // Returns the 0-based disk index for 'path' (path must be a FS path, not

    // hdfs path).

    static int disk_id(const char* path);

    // Returns the device name (e.g. sda) for disk_id

    static const std::string& device_name(int disk_id) {

        DCHECK_GE(disk_id, 0);

        DCHECK_LT(disk_id, _s_disks.size());

        return _s_disks[disk_id].name;

    }

    static bool is_rotational(int disk_id) {

        DCHECK_GE(disk_id, 0);

        DCHECK_LT(disk_id, _s_disks.size());

        return _s_disks[disk_id].is_rotational;

    }

    static std::string debug_string();

    // get disk devices of given path

    static Status get_disk_devices(const std::vector<std::string>& paths,

                                   std::set<std::string>* devices);

private:

    static bool _s_initialized;

    struct Disk {

        // Name of the disk (e.g. sda)

        std::string name;

        // 0 based index.  Does not map to anything in the system, useful to index into

        // our structures

        int id;

        bool is_rotational;

        Disk() : name(""), id(0) {}

        Disk(const std::string& name) : name(name), id(0), is_rotational(true) {}

        Disk(const std::string& name, int id) : name(name), id(id), is_rotational(true) {}

        Disk(const std::string& name, int id, bool is_rotational)

                : name(name), id(id), is_rotational(is_rotational) {}

    };

    // All disks

    static std::vector<Disk> _s_disks;

    // mapping of dev_ts to disk ids

    static std::map<dev_t, int> _s_device_id_to_disk_id;

    // mapping of devices names to disk ids

    static std::map<std::string, int> _s_disk_name_to_disk_id;

    static int _s_num_datanode_dirs;

    static void get_device_names();

};

} // namespace doris