Aaru/Aaru.Core/DataFile.cs

// /***************************************************************************
// Aaru Data Preservation Suite
// ----------------------------------------------------------------------------
//
// Filename       : DataFile.cs
// Author(s)      : Natalia Portillo <claunia@claunia.com>
//
// Component      : Core algorithms.
//
// --[ Description ] ----------------------------------------------------------
//
//     Abstracts writing to files.
//
// --[ License ] --------------------------------------------------------------
//
//     This program is free software: you can redistribute it and/or modify
//     it under the terms of the GNU General public License as
//     published by the Free Software Foundation, either version 3 of the
//     License, or (at your option) any later version.
//
//     This program is distributed in the hope that it will be useful,
//     but WITHOUT ANY WARRANTY; without even the implied warranty of
//     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//     GNU General public License for more details.
//
//     You should have received a copy of the GNU General public License
//     along with this program.  If not, see <http://www.gnu.org/licenses/>.
//
// ----------------------------------------------------------------------------
// Copyright © 2011-2023 Natalia Portillo
// ****************************************************************************/

using System.Diagnostics.CodeAnalysis;
using System.IO;
using Aaru.Console;
using Aaru.Helpers;

namespace Aaru.Core;

/// <summary>Abstracts a datafile with a block based interface</summary>
[SuppressMessage("ReSharper", "UnusedMethodReturnValue.Global")]
[SuppressMessage("ReSharper", "UnusedMember.Global")]
public sealed class DataFile
{
    readonly FileStream _dataFs;

    /// <summary>Opens, or create, a new file</summary>
    /// <param name="outputFile">File</param>
    public DataFile(string outputFile) =>
        _dataFs = new FileStream(outputFile, FileMode.OpenOrCreate, FileAccess.ReadWrite);

    /// <summary>Current file position</summary>
    public long Position => _dataFs.Position;

    /// <summary>Closes the file</summary>
    public void Close() => _dataFs?.Close();

    /// <summary>Reads bytes at current position</summary>
    /// <param name="array">Array to place read data within</param>
    /// <param name="offset">Offset of <see cref="array" /> where data will be read</param>
    /// <param name="count">How many bytes to read</param>
    /// <returns>How many bytes were read</returns>
    public int Read(byte[] array, int offset, int count) => _dataFs.EnsureRead(array, offset, count);

    /// <summary>Seeks to the specified block</summary>
    /// <param name="block">Block to seek to</param>
    /// <param name="blockSize">Block size in bytes</param>
    /// <returns>Position</returns>
    public long Seek(ulong block, ulong blockSize) => _dataFs.Seek((long)(block * blockSize), SeekOrigin.Begin);

    /// <summary>Seeks to specified byte position</summary>
    /// <param name="offset">Byte position</param>
    /// <param name="origin">Where to count for position</param>
    /// <returns>Position</returns>
    public long Seek(ulong offset, SeekOrigin origin) => _dataFs.Seek((long)offset, origin);

    /// <summary>Seeks to specified byte position</summary>
    /// <param name="offset">Byte position</param>
    /// <param name="origin">Where to count for position</param>
    /// <returns>Position</returns>
    public long Seek(long offset, SeekOrigin origin) => _dataFs.Seek(offset, origin);

    /// <summary>Writes data at current position</summary>
    /// <param name="data">Data</param>
    public void Write(byte[] data) => Write(data, 0, data.Length);

    /// <summary>Writes data at current position</summary>
    /// <param name="data">Data</param>
    /// <param name="offset">Offset of data from where to start taking data to write</param>
    /// <param name="count">How many bytes to write</param>
    public void Write(byte[] data, int offset, int count) => _dataFs.Write(data, offset, count);

    /// <summary>Writes data at specified block</summary>
    /// <param name="data">Data</param>
    /// <param name="block">Block</param>
    /// <param name="blockSize">Bytes per block</param>
    public void WriteAt(byte[] data, ulong block, uint blockSize) => WriteAt(data, block, blockSize, 0, data.Length);

    /// <summary>Writes data at specified block</summary>
    /// <param name="data">Data</param>
    /// <param name="block">Block</param>
    /// <param name="blockSize">Bytes per block</param>
    /// <param name="offset">Offset of data from where to start taking data to write</param>
    /// <param name="count">How many bytes to write</param>
    public void WriteAt(byte[] data, ulong block, uint blockSize, int offset, int count)
    {
        _dataFs.Seek((long)(block * blockSize), SeekOrigin.Begin);
        _dataFs.Write(data, offset, count);
    }

    /// <summary>Writes data to a newly created file</summary>
    /// <param name="who">Who asked the file to be written (class, plugin, etc.)</param>
    /// <param name="data">Data to write</param>
    /// <param name="outputPrefix">First part of the file name</param>
    /// <param name="outputSuffix">Last part of the file name</param>
    /// <param name="whatWriting">What is the data about?</param>
    public static void WriteTo(string who, string outputPrefix, string outputSuffix, string whatWriting, byte[] data)
    {
        if(!string.IsNullOrEmpty(outputPrefix) && !string.IsNullOrEmpty(outputSuffix))
            WriteTo(who, outputPrefix + outputSuffix, data, whatWriting);
    }

    /// <summary>Writes data to a newly created file</summary>
    /// <param name="who">Who asked the file to be written (class, plugin, etc.)</param>
    /// <param name="filename">Filename to create</param>
    /// <param name="data">Data to write</param>
    /// <param name="whatWriting">What is the data about?</param>
    /// <param name="overwrite">If set to <c>true</c> overwrites the file, does nothing otherwise</param>
    public static void WriteTo(string who, string filename, byte[] data, string whatWriting = null,
                               bool   overwrite = false)
    {
        if(string.IsNullOrEmpty(filename))
            return;

        if(File.Exists(filename))
        {
            if(overwrite)
                File.Delete(filename);
            else
            {
                AaruConsole.ErrorWriteLine(Localization.Core.Not_overwriting_file_0, filename);

                return;
            }
        }

        try
        {
            AaruConsole.DebugWriteLine(who, string.Format(Localization.Core.Writing_0_to_1, whatWriting, filename));
            var outputFs = new FileStream(filename, FileMode.CreateNew);
            outputFs.Write(data, 0, data.Length);
            outputFs.Close();
        }
        catch
        {
            AaruConsole.ErrorWriteLine(Localization.Core.Unable_to_write_file_0, filename);
        }
    }
}