filesystem.h

/*
 * 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 <memory>
#include <optional>
#include <string>
#include <vector>
 
#include "graphar/result.h"
#include "graphar/status.h"
#include "graphar/types.h"
#include "graphar/util.h"
 
#include "graphar/reader_util.h"
 
// forward declarations
namespace arrow {
class Buffer;
class Table;
}  // namespace arrow
 
namespace arrow::fs {
class FileSystem;
}  // namespace arrow::fs
 
namespace arrow::io {
class RandomAccessFile;
}  // namespace arrow::io
 
namespace arrow::dataset {
class FileFormat;
}  // namespace arrow::dataset
 
namespace graphar {
 
class FileSystem {
 public:
  explicit FileSystem(std::shared_ptr<arrow::fs::FileSystem> arrow_fs)
      : arrow_fs_(arrow_fs) {}
 
  ~FileSystem();
 
  Result<std::shared_ptr<arrow::Table>> ReadFileToTable(
      const std::string& path, FileType file_type,
      const util::FilterOptions& options = {}) const noexcept;
 
  template <typename T>
  Result<T> ReadFileToValue(const std::string& path) const noexcept;
 
  template <typename T>
  Status WriteValueToFile(const T& value, const std::string& path) const
      noexcept;
 
  Status WriteTableToFile(const std::shared_ptr<arrow::Table>& table,
                          FileType file_type, const std::string& path) const
      noexcept;
 
  Status CopyFile(const std::string& src_path,
                  const std::string& dst_path) const noexcept;
 
  Result<IdType> GetFileNumOfDir(const std::string& dir_path,
                                 bool recursive = false) const noexcept;
 
 private:
  std::shared_ptr<arrow::dataset::FileFormat> GetFileFormat(
      const FileType file_type) const;
 
 private:
  std::shared_ptr<arrow::fs::FileSystem> arrow_fs_;
};
 
Result<std::shared_ptr<FileSystem>> FileSystemFromUriOrPath(
    const std::string& uri, std::string* out_path = nullptr);
 
Status InitializeS3();
 
Status FinalizeS3();
 
}  // namespace graphar