IFileSystem

IFileSystemMount is for mounting filesystems to virtual filesystem.

/// <summary>FileSystem that can mount other filesystems into its directory tree.</summary>
public interface IFileSystemMount : IFileSystem, IMountOption
{
    /// <summary>
    /// Mounts zero, one or many <see cref="IFileSystem"/> with optional <see cref="IOption"/> in the parent filesystem.
    /// 
    /// If no mounts are provided, then creates empty virtual directory.
    /// If one mount is provided, then mounts that to parent filesystem, with possible mount option.
    /// If multiple mounts are provided, then mounts a composition of all the filesystem, with the precedence of the order in the provided array.
    /// 
    /// If previous mounts exist at the <paramref name="path"/>, then replaces them with new configuration.
    /// 
    /// If parent filesystem had observers monitoring the <paramref name="path"/>, then observers are notified with new emerged files from the mounted filesystems.
    /// 
    /// The <paramref name="path"/> parameter must end with directory separator character '/', unless root directory "" is mounted.
    /// 
    /// If there is an open stream to a mounted filesystem, then the file is unlinked from the parent filesystem, but stream maintains open.
    /// </summary>
    /// <param name="path"></param>
    /// <param name="mounts">(optional) filesystem and option infos</param>
    /// <param name="option">(optional) operation specific option; capability constraint, a session, security token or credential. Used for authenticating, authorizing or restricting the operation.</param>
    /// <returns>this (parent filesystem)</returns>
    /// <exception cref="NotSupportedException">If operation is not supported</exception>
    IFileSystem Mount(string path, FileSystemAssignment[] mounts, IOption? option = null);

    /// <summary>
    /// Unmount a filesystem at <paramref name="path"/>.
    /// 
    /// If there is no mount at <paramref name="path"/>, then does nothing.
    /// If there is an open stream to previously mounted filesystem, that the file is unlinked, but stream remains open.
    /// If there are observers monitoring <paramref name="path"/> in the parent filesystem, then the unmounted files are notified as being deleted.
    /// </summary>
    /// <param name="path"></param>
    /// <param name="option">(optional) operation specific option; capability constraint, a session, security token or credential. Used for authenticating, authorizing or restricting the operation.</param>
    /// <returns>this (parent filesystem)</returns>
    /// <exception cref="NotSupportedException">If operation is not supported</exception>
    IFileSystem Unmount(string path, IOption? option = null);

    /// <summary>List all mounts.</summary>
    /// <param name="option">operation specific option; capability constraint, a session, security token or credential. Used for authenticating, authorizing or restricting the operation.</param>
    /// <exception cref="NotSupportedException">If operation is not supported</exception>
    IMountEntry[] ListMountPoints(IOption? option = null);
}

IFileSystemMountAsync is async for mounting filesystems to virtual filesystem.

/// <summary>FileSystem that can mount other filesystems into its directory tree.</summary>
public interface IFileSystemMountAsync : IFileSystem, IMountOption
{
    /// <summary>
    /// Mounts zero, one or many <see cref="IFileSystem"/> with optional <see cref="IOption"/> in the parent filesystem.
    /// 
    /// If no mounts are provided, then creates empty virtual directory.
    /// If one mount is provided, then mounts that to parent filesystem, with possible mount option.
    /// If multiple mounts are provided, then mounts a composition of all the filesystem, with the precedence of the order in the provided array.
    /// 
    /// If previous mounts exist at the <paramref name="path"/>, then replaces them with new configuration.
    /// 
    /// If parent filesystem had observers monitoring the <paramref name="path"/>, then observers are notified with new emerged files from the mounted filesystems.
    /// 
    /// The <paramref name="path"/> parameter must end with directory separator character '/', unless root directory "" is mounted.
    /// 
    /// If there is an open stream to a mounted filesystem, then the file is unlinked from the parent filesystem, but stream maintains open.
    /// </summary>
    /// <param name="path"></param>
    /// <param name="mounts">(optional) filesystem and option infos</param>
    /// <param name="option">(optional) operation specific option; capability constraint, a session, security token or credential. Used for authenticating, authorizing or restricting the operation.</param>
    /// <returns>this (parent filesystem)</returns>
    /// <exception cref="NotSupportedException">If operation is not supported</exception>
    Task<IFileSystem> MountAsync(string path, FileSystemAssignment[] mounts, IOption? option = null);

    /// <summary>
    /// Unmount a filesystem at <paramref name="path"/>.
    /// 
    /// If there is no mount at <paramref name="path"/>, then does nothing.
    /// If there is an open stream to previously mounted filesystem, that the file is unlinked, but stream remains open.
    /// If there are observers monitoring <paramref name="path"/> in the parent filesystem, then the unmounted files are notified as being deleted.
    /// </summary>
    /// <param name="path"></param>
    /// <param name="option">(optional) operation specific option; capability constraint, a session, security token or credential. Used for authenticating, authorizing or restricting the operation.</param>
    /// <returns>this (parent filesystem)</returns>
    /// <exception cref="NotSupportedException">If operation is not supported</exception>
    Task<IFileSystem> UnmountAsync(string path, IOption? option = null);

    /// <summary>List all mounts.</summary>
    /// <param name="option">operation specific option; capability constraint, a session, security token or credential. Used for authenticating, authorizing or restricting the operation.</param>
    /// <exception cref="NotSupportedException">If operation is not supported</exception>
    Task<IMountEntry[]> ListMountPointsAsync(IOption? option = null);
}