public void CreateDir(ResourcePath path)
{
if (!path.IsRooted)
{
throw new ArgumentException("Path must be rooted", nameof(path));
}
path = path.Clean();
var directory = _rootDirectoryNode;
foreach (var segment in path.EnumerateSegments())
{
if (directory.Children.TryGetValue(segment, out var child))
{
if (!(child is DirectoryNode childDir))
{
throw new ArgumentException("A file already exists at that location.");
}
directory = childDir;
continue;
}
var newDir = new DirectoryNode();
directory.Children.Add(segment, newDir);
}
}
private static string GetFullPath(string root, ResourcePath path)
{
var relPath = path.Clean().ToRelativeSystemPath();
if (relPath.Contains("\\..") || relPath.Contains("/.."))
{
// Hard cap on any exploit smuggling a .. in there.
// Since that could allow leaving sandbox.
throw new InvalidOperationException("This branch should never be reached.");
}
return(Path.GetFullPath(Path.Combine(root, relPath)));
}
public void Delete(ResourcePath path)
{
if (!path.IsRooted)
{
throw new ArgumentException("Path must be rooted", nameof(path));
}
path = path.Clean();
var pathParent = path.Directory;
if (!TryGetNodeAt(pathParent, out var parent) || !(parent is DirectoryNode directory))
{
return;
}
directory.Children.Remove(path.Filename);
}
private bool TryGetNodeAt(ResourcePath path, out INode node)
{
if (!path.IsRooted)
{
throw new ArgumentException("Path must be rooted", nameof(path));
}
path = path.Clean();
if (path == ResourcePath.Root)
{
node = _rootDirectoryNode;
return(true);
}
var directory = _rootDirectoryNode;
var segments = path.EnumerateSegments().ToArray();
for (var i = 0; i < segments.Length; i++)
{
var segment = segments[i];
if (!directory.Children.TryGetValue(segment, out var child))
{
node = default;
return(false);
}
if (i == segments.Length - 1)
{
node = child;
return(true);
}
directory = (DirectoryNode)child;
}
throw new InvalidOperationException("Unreachable.");
}
private static string GetFullPath(string root, ResourcePath path)
{
var relPath = path.Clean().ToRelativePath().ToString();
return(Path.GetFullPath(Path.Combine(root, relPath)));
}
public Stream Open(ResourcePath path, FileMode fileMode)
{
if (!path.IsRooted)
{
throw new ArgumentException("Path must be rooted", nameof(path));
}
path = path.Clean();
var parentPath = path.Directory;
if (!TryGetNodeAt(parentPath, out var parent) || !(parent is DirectoryNode parentDir))
{
throw new ArgumentException("Parent directory does not exist.");
}
var fileName = path.Filename;
if (parentDir.Children.TryGetValue(fileName, out var maybeFileNode) && maybeFileNode is DirectoryNode)
{
throw new ArgumentException("There is a directory at that location.");
}
var fileNode = (FileNode)maybeFileNode;
switch (fileMode)
{
case FileMode.Append:
{
if (fileNode == null)
{
fileNode = new FileNode();
parentDir.Children.Add(fileName, fileNode);
}
return(new VirtualFileStream(fileNode.Contents, false, true, fileNode.Contents.Length));
}
case FileMode.Create:
{
if (fileNode == null)
{
fileNode = new FileNode();
parentDir.Children.Add(fileName, fileNode);
}
else
{
// Clear contents if it already exists.
fileNode.Contents.SetLength(0);
}
return(new VirtualFileStream(fileNode.Contents, true, true, 0));
}
case FileMode.CreateNew:
{
if (fileNode != null)
{
throw new IOException("File already exists.");
}
fileNode = new FileNode();
parentDir.Children.Add(fileName, fileNode);
return(new VirtualFileStream(fileNode.Contents, true, true, 0));
}
case FileMode.Open:
{
if (fileNode == null)
{
throw new FileNotFoundException();
}
return(new VirtualFileStream(fileNode.Contents, true, true, 0));
}
case FileMode.OpenOrCreate:
{
if (fileNode == null)
{
fileNode = new FileNode();
parentDir.Children.Add(fileName, fileNode);
}
return(new VirtualFileStream(fileNode.Contents, true, true, 0));
}
case FileMode.Truncate:
{
if (fileNode == null)
{
throw new FileNotFoundException();
}
fileNode.Contents.SetLength(0);
return(new VirtualFileStream(fileNode.Contents, true, true, 0));
}
default:
throw new ArgumentOutOfRangeException(nameof(fileMode), fileMode, null);
}
}