Files
Aaru/Aaru.Filesystems/FATX/File.cs

282 lines
9.3 KiB
C#

// /***************************************************************************
// Aaru Data Preservation Suite
// ----------------------------------------------------------------------------
//
// Filename : File.cs
// Author(s) : Natalia Portillo <claunia@claunia.com>
//
// Component : FATX filesystem plugin.
//
// --[ License ] --------------------------------------------------------------
//
// This library is free software; you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as
// published by the Free Software Foundation; either version 2.1 of the
// License, or (at your option) any later version.
//
// This library 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
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, see <http://www.gnu.org/licenses/>.
//
// ----------------------------------------------------------------------------
// Copyright © 2011-2025 Natalia Portillo
// ****************************************************************************/
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using Aaru.CommonTypes.Enums;
using Aaru.CommonTypes.Interfaces;
using Aaru.CommonTypes.Structs;
using Aaru.Helpers;
using FileAttributes = Aaru.CommonTypes.Structs.FileAttributes;
namespace Aaru.Filesystems;
public sealed partial class XboxFatPlugin
{
uint[] GetClusters(uint startCluster)
{
if(startCluster == 0) return null;
if(_fat16 is null)
{
if(startCluster >= _fat32.Length) return null;
}
else if(startCluster >= _fat16.Length) return null;
List<uint> clusters = [];
uint nextCluster = startCluster;
if(_fat16 is null)
{
while((nextCluster & FAT32_MASK) > 0 && (nextCluster & FAT32_MASK) <= FAT32_RESERVED)
{
clusters.Add(nextCluster);
nextCluster = _fat32[nextCluster];
}
}
else
{
while(nextCluster is > 0 and <= FAT16_RESERVED)
{
clusters.Add(nextCluster);
nextCluster = _fat16[nextCluster];
}
}
return clusters.ToArray();
}
ErrorNumber GetFileEntry(string path, out DirectoryEntry entry)
{
entry = new DirectoryEntry();
string cutPath = path.StartsWith('/') ? path[1..].ToLower(_cultureInfo) : path.ToLower(_cultureInfo);
string[] pieces = cutPath.Split(['/'], StringSplitOptions.RemoveEmptyEntries);
if(pieces.Length == 0) return ErrorNumber.InvalidArgument;
var parentPath = string.Join("/", pieces, 0, pieces.Length - 1);
ErrorNumber err = OpenDir(parentPath, out IDirNode node);
if(err != ErrorNumber.NoError) return err;
CloseDir(node);
Dictionary<string, DirectoryEntry> parent;
if(pieces.Length == 1)
parent = _rootDirectory;
else if(!_directoryCache.TryGetValue(parentPath, out parent)) return ErrorNumber.InvalidArgument;
KeyValuePair<string, DirectoryEntry> dirent =
parent.FirstOrDefault(t => t.Key.ToLower(_cultureInfo) == pieces[^1]);
if(string.IsNullOrEmpty(dirent.Key)) return ErrorNumber.NoSuchFile;
entry = dirent.Value;
return ErrorNumber.NoError;
}
#region IReadOnlyFilesystem Members
/// <inheritdoc />
public ErrorNumber GetAttributes(string path, out FileAttributes attributes)
{
attributes = new FileAttributes();
if(!_mounted) return ErrorNumber.AccessDenied;
ErrorNumber err = Stat(path, out FileEntryInfo stat);
if(err != ErrorNumber.NoError) return err;
attributes = stat.Attributes;
return ErrorNumber.NoError;
}
/// <inheritdoc />
public ErrorNumber OpenFile(string path, out IFileNode node)
{
node = null;
if(!_mounted) return ErrorNumber.AccessDenied;
ErrorNumber err = Stat(path, out FileEntryInfo stat);
if(err != ErrorNumber.NoError) return err;
if(stat.Attributes.HasFlag(FileAttributes.Directory) && !_debug) return ErrorNumber.IsDirectory;
uint[] clusters = GetClusters((uint)stat.Inode);
node = new FatxFileNode
{
Path = path,
Length = stat.Length,
Offset = 0,
Clusters = clusters
};
return ErrorNumber.NoError;
}
/// <inheritdoc />
public ErrorNumber CloseFile(IFileNode node)
{
if(!_mounted) return ErrorNumber.AccessDenied;
if(node is not FatxFileNode mynode) return ErrorNumber.InvalidArgument;
mynode.Clusters = null;
return ErrorNumber.NoError;
}
/// <inheritdoc />
public ErrorNumber ReadFile(IFileNode node, long length, byte[] buffer, out long read)
{
read = 0;
if(!_mounted) return ErrorNumber.AccessDenied;
if(buffer is null || buffer.Length < length) return ErrorNumber.InvalidArgument;
if(node is not FatxFileNode mynode) return ErrorNumber.InvalidArgument;
read = length;
if(length + mynode.Offset >= mynode.Length) read = mynode.Length - mynode.Offset;
long firstCluster = mynode.Offset / _bytesPerCluster;
long offsetInCluster = mynode.Offset % _bytesPerCluster;
long sizeInClusters = (read + offsetInCluster) / _bytesPerCluster;
if((read + offsetInCluster) % _bytesPerCluster > 0) sizeInClusters++;
var ms = new MemoryStream();
for(var i = 0; i < sizeInClusters; i++)
{
if(i + firstCluster >= mynode.Clusters.Length) return ErrorNumber.InvalidArgument;
ErrorNumber errno =
_imagePlugin.ReadSectors(_firstClusterSector +
(mynode.Clusters[i + firstCluster] - 1) * _sectorsPerCluster,
false,
_sectorsPerCluster,
out byte[] buf,
out _);
if(errno != ErrorNumber.NoError) return errno;
ms.Write(buf, 0, buf.Length);
}
ms.Position = offsetInCluster;
ms.EnsureRead(buffer, 0, (int)read);
mynode.Offset += read;
return ErrorNumber.NoError;
}
/// <inheritdoc />
public ErrorNumber Stat(string path, out FileEntryInfo stat)
{
stat = null;
if(!_mounted) return ErrorNumber.AccessDenied;
if(_debug && (string.IsNullOrEmpty(path) || path is "$" or "/"))
{
stat = new FileEntryInfo
{
Attributes = FileAttributes.Directory | FileAttributes.System | FileAttributes.Hidden,
Blocks = GetClusters(_superblock.rootDirectoryCluster).Length,
BlockSize = _bytesPerCluster,
Length = GetClusters(_superblock.rootDirectoryCluster).Length * _bytesPerCluster,
Inode = _superblock.rootDirectoryCluster,
Links = 1
};
return ErrorNumber.NoError;
}
ErrorNumber err = GetFileEntry(path, out DirectoryEntry entry);
if(err != ErrorNumber.NoError) return err;
stat = new FileEntryInfo
{
Attributes = new FileAttributes(),
Blocks = entry.length / _bytesPerCluster,
BlockSize = _bytesPerCluster,
Length = entry.length,
Inode = entry.firstCluster,
Links = 1,
CreationTime =
_littleEndian
? DateHandlers.DosToDateTime(entry.creationDate, entry.creationTime).AddYears(20)
: DateHandlers.DosToDateTime(entry.creationTime, entry.creationDate),
AccessTime =
_littleEndian
? DateHandlers.DosToDateTime(entry.lastAccessDate, entry.lastAccessTime).AddYears(20)
: DateHandlers.DosToDateTime(entry.lastAccessTime, entry.lastAccessDate),
LastWriteTime = _littleEndian
? DateHandlers.DosToDateTime(entry.lastWrittenDate, entry.lastWrittenTime).AddYears(20)
: DateHandlers.DosToDateTime(entry.lastWrittenTime, entry.lastWrittenDate)
};
if(entry.length % _bytesPerCluster > 0) stat.Blocks++;
if(entry.attributes.HasFlag(Attributes.Directory))
{
stat.Attributes |= FileAttributes.Directory;
stat.Blocks = GetClusters(entry.firstCluster).Length;
stat.Length = stat.Blocks * stat.BlockSize;
}
if(entry.attributes.HasFlag(Attributes.ReadOnly)) stat.Attributes |= FileAttributes.ReadOnly;
if(entry.attributes.HasFlag(Attributes.Hidden)) stat.Attributes |= FileAttributes.Hidden;
if(entry.attributes.HasFlag(Attributes.System)) stat.Attributes |= FileAttributes.System;
if(entry.attributes.HasFlag(Attributes.Archive)) stat.Attributes |= FileAttributes.Archive;
return ErrorNumber.NoError;
}
#endregion
}