file_io.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 <cstddef>
#include <cstdint>
#include <memory>
#include <optional>
#include <span>
#include <string>
#include <string_view>
#include <vector>
 
#include "iceberg/iceberg_export.h"
#include "iceberg/result.h"
#include "iceberg/storage_credential.h"
 
namespace iceberg {
 
class SupportsStorageCredentials;
 
class ICEBERG_EXPORT SeekableInputStream {
 public:
  virtual ~SeekableInputStream() = default;
 
  virtual Result<int64_t> Position() const = 0;
 
  virtual Status Seek(int64_t position) = 0;
 
  virtual Result<int64_t> Read(std::span<std::byte> out) = 0;
 
  virtual Status ReadFully(int64_t position, std::span<std::byte> out) = 0;
 
  virtual Status Close() = 0;
};
 
class ICEBERG_EXPORT PositionOutputStream {
 public:
  virtual ~PositionOutputStream() = default;
 
  virtual Result<int64_t> Position() const = 0;
 
  virtual Result<int64_t> StoredLength() const { return Position(); }
 
  virtual Status Write(std::span<const std::byte> data) = 0;
 
  virtual Status Flush() = 0;
 
  virtual Status Close() = 0;
};
 
class ICEBERG_EXPORT InputFile {
 public:
  virtual ~InputFile() = default;
 
  virtual std::string_view location() const = 0;
 
  virtual Result<int64_t> Size() const = 0;
 
  virtual Result<std::unique_ptr<SeekableInputStream>> Open() = 0;
};
 
class ICEBERG_EXPORT OutputFile {
 public:
  virtual ~OutputFile() = default;
 
  virtual std::string_view location() const = 0;
 
  virtual Result<std::unique_ptr<PositionOutputStream>> Create() = 0;
 
  virtual Result<std::unique_ptr<PositionOutputStream>> CreateOrOverwrite() = 0;
};
 
class ICEBERG_EXPORT FileIO {
 public:
  FileIO() = default;
  virtual ~FileIO() = default;
 
  virtual Result<std::unique_ptr<InputFile>> NewInputFile(std::string file_location);
 
  virtual Result<std::unique_ptr<InputFile>> NewInputFile(std::string file_location,
                                                          size_t length);
 
  virtual Result<std::unique_ptr<OutputFile>> NewOutputFile(std::string file_location);
 
  virtual Result<std::string> ReadFile(const std::string& file_location,
                                       std::optional<size_t> length);
 
  virtual Status WriteFile(const std::string& file_location, std::string_view content);
 
  virtual Status DeleteFile(const std::string& file_location) {
    return NotImplemented("DeleteFile not implemented");
  }
 
  virtual Status DeleteFiles(const std::vector<std::string>& file_locations);
 
  virtual SupportsStorageCredentials* AsSupportsStorageCredentials() { return nullptr; }
};
 
class ICEBERG_EXPORT SupportsStorageCredentials {
 public:
  virtual ~SupportsStorageCredentials() = default;
 
  virtual Status SetStorageCredentials(
      const std::vector<StorageCredential>& storage_credentials) = 0;
 
  virtual const std::vector<StorageCredential>& credentials() const = 0;
};
 
}  // namespace iceberg