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// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
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//
//   http://www.apache.org/licenses/LICENSE-2.0
//
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// software distributed under the License is distributed on an
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// specific language governing permissions and limitations
// under the License.

#ifndef DORIS_BE_SRC_RUNTIME_SNAPSHOT_LOADER_H
#define DORIS_BE_SRC_RUNTIME_SNAPSHOT_LOADER_H

#include <stdint.h>

#include <map>
#include <string>
#include <vector>

#include "common/status.h"
#include "gen_cpp/Types_types.h"
#include "olap/tablet.h"
#include "runtime/client_cache.h"

namespace doris {

class ExecEnv;
class StorageBackend;
struct FileStat;

/*
 * Upload:
 * upload() will upload the specified snapshot
 * to remote storage via broker.
 * Each call of upload() is responsible for several tablet snapshots.
 *
 * It will try to get the existing files in remote storage,
 * and only upload the incremental part of files.
 *
 * Download:
 * download() will download the remote tablet snapshot files
 * to local snapshot dir via broker.
 * It will also only download files which does not exist in local dir.
 *
 * Move:
 * move() is the final step of restore process. it will replace the 
 * old tablet data dir with the newly downloaded snapshot dir.
 * and reload the tablet header to take this tablet on line.
 * 
 */
class SnapshotLoader {
public:
    SnapshotLoader(ExecEnv* env, int64_t job_id, int64_t task_id);
    SnapshotLoader(ExecEnv* env, int64_t job_id, int64_t task_id,
                   const TNetworkAddress& broker_addr,
                   const std::map<std::string, std::string>& broker_prop);
    SnapshotLoader(ExecEnv* env, int64_t job_id, int64_t task_id,
                   const std::map<std::string, std::string>& broker_prop);

    ~SnapshotLoader();

    Status upload(const std::map<std::string, std::string>& src_to_dest_path,
                  std::map<int64_t, std::vector<std::string>>* tablet_files);

    Status download(const std::map<std::string, std::string>& src_to_dest_path,
                    std::vector<int64_t>* downloaded_tablet_ids);

    Status move(const std::string& snapshot_path, TabletSharedPtr tablet, bool overwrite);

private:
    Status _get_tablet_id_and_schema_hash_from_file_path(const std::string& src_path,
                                                         int64_t* tablet_id, int32_t* schema_hash);

    Status _check_local_snapshot_paths(const std::map<std::string, std::string>& src_to_dest_path,
                                       bool check_src);

    Status _get_existing_files_from_local(const std::string& local_path,
                                          std::vector<std::string>* local_files);

    bool _end_with(const std::string& str, const std::string& match);

    Status _replace_tablet_id(const std::string& file_name, int64_t tablet_id,
                              std::string* new_file_name);

    Status _get_tablet_id_from_remote_path(const std::string& remote_path, int64_t* tablet_id);

    Status _report_every(int report_threshold, int* counter, int finished_num, int total_num,
                         TTaskType::type type);

private:
    ExecEnv* _env;
    int64_t _job_id;
    int64_t _task_id;
    const TNetworkAddress _broker_addr;
    const std::map<std::string, std::string> _prop;
    std::unique_ptr<StorageBackend> _storage_backend;
};

} // end namespace doris

#endif // DORIS_BE_SRC_RUNTIME_SNAPSHOT_LOADER_H