// 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 <stddef.h>

#include <atomic>

#include <memory>

#include <string>

#include "common/status.h"

#include "io/fs/file_handle_cache.h"

#include "io/fs/file_reader.h"

#include "io/fs/file_system.h"

#include "io/fs/hdfs.h"

#include "io/fs/hdfs_file_system.h"

#include "io/fs/path.h"

#include "util/slice.h"

namespace doris::io {

struct IOContext;

class HdfsFileReader final : public FileReader {

public:

    // Accepted path format:

    // - fs_name/path_to_file

    // - /path_to_file

    // TODO(plat1ko): Support related path for cloud mode

    static Result<FileReaderSPtr> create(Path path, const hdfsFS& fs, std::string fs_name,

                                         const FileReaderOptions& opts, RuntimeProfile* profile);

    HdfsFileReader(Path path, std::string fs_name, FileHandleCache::Accessor accessor,

                   RuntimeProfile* profile, int64_t mtime = 0);

    ~HdfsFileReader() override;

    Status close() override;

    const Path& path() const override { return _path; }

    size_t size() const override { return _handle->file_size(); }

    bool closed() const override { return _closed.load(std::memory_order_acquire); }

    int64_t mtime() const override { return _mtime; }

protected:

    Status read_at_impl(size_t offset, Slice result, size_t* bytes_read,

                        const IOContext* io_ctx) override;

    void _collect_profile_before_close() override;

    Status do_read_at_impl(size_t offset, Slice result, size_t* bytes_read,

                           const IOContext* io_ctx);

private:

#ifdef USE_HADOOP_HDFS

    struct HDFSProfile {

        RuntimeProfile::Counter* total_bytes_read = nullptr;

        RuntimeProfile::Counter* total_local_bytes_read = nullptr;

        RuntimeProfile::Counter* total_short_circuit_bytes_read = nullptr;

        RuntimeProfile::Counter* total_total_zero_copy_bytes_read = nullptr;

        RuntimeProfile::Counter* total_hedged_read = nullptr;

        RuntimeProfile::Counter* hedged_read_in_cur_thread = nullptr;

        RuntimeProfile::Counter* hedged_read_wins = nullptr;

    };

#endif

    Path _path;

    std::string _fs_name;

    FileHandleCache::Accessor _accessor;

    CachedHdfsFileHandle* _handle = nullptr; // owned by _cached_file_handle

    std::atomic<bool> _closed = false;

    RuntimeProfile* _profile = nullptr;

    int64_t _mtime;

#ifdef USE_HADOOP_HDFS

    HDFSProfile _hdfs_profile;

#endif

};

} // namespace doris::io