/// <summary>
/// Allocates a new DirectoryEntry object for the given settings.
/// </summary>
/// <param name="parent">The parent directory entry.</param>
/// <param name="name">The name of the entry to create.</param>
/// <param name="node">The vfs node referenced by the directory entry.</param>
/// <returns>The allocated directory entry.</returns>
/// <exception cref="System.ArgumentNullException">If any one of the parameters is null.</exception>
/// <exception cref="System.ArgumentException">If the name is zero-length.</exception>
/// <remarks>
/// This method is used to control the DirectoryEntry allocation and maintain a cache of them. Also used to
/// prevent infinite name allocations.
/// </remarks>
public static DirectoryEntry Allocate(DirectoryEntry parent, string name, IVfsNode node)
{
//#if VFS_NO_EXCEPTIONS
if (parent == null)
{
throw new System.ArgumentNullException(@"parent");
}
if (name == null)
{
throw new System.ArgumentNullException(@"name");
}
if (node == null)
{
throw new System.ArgumentNullException(@"node");
}
if (name.Length == 0)
{
throw new System.ArgumentException(@"Invalid directory entry name."); // , @"name"
}
// FIXME: Add precondition check for invalid characters
// FIXME: Localize exception messages
//#endif // #if VFS_NO_EXCEPTIONS
DirectoryEntry directory = new DirectoryEntry();
directory.Setup(parent, name, node);
return(directory);
}
/// <summary>
///
/// </summary>
/// <param name="parent"></param>
/// <param name="name"></param>
/// <param name="node"></param>
private void Setup(DirectoryEntry parent, string name, IVfsNode node)
{
if (!System.Object.ReferenceEquals(this, parent))
{
parent.InsertChild(this);
}
this.parent = parent;
this.name = name;
inode = node;
}
/// <summary>
/// Allocates a vfs root directory entry.
/// </summary>
/// <param name="node">The vfs node, which corresponds to the root directory.</param>
/// <returns>The created directory entry.</returns>
/// <exception cref="System.ArgumentNullException">The specified node is invalid.</exception>
/// <remarks>
/// This method creates a directory entry, which has some special properties. The first one is, that
/// its parent is itself. This provides for the ability to cd .. on the root to stay on the root.
/// <para/>
/// The next ability is to create specialized root directories to isolate processes from the remainder
/// of the filesystem. Setting a root directory created using this method effectively limits the process
/// to access inside of the newly created namespace.
/// </remarks>
public static DirectoryEntry AllocateRoot(IVfsNode node)
{
#if VFS_NO_EXCEPTIONS
if (node == null)
{
throw new ArgumentNullException(@"node");
}
#endif // #if VFS_NO_EXCEPTIONS
DirectoryEntry result = new DirectoryEntry();
result.Setup(result, System.String.Empty, node);
return(result);
}
public override void Delete (IVfsNode child, DirectoryEntry dentry)
{
FAT fs = this.FileSystem as FAT;
uint childBlock = (child as VfsDirectory).directoryCluster;
FAT.DirectoryEntryLocation location = fs.FindEntry (new FAT.FatMatchClusterComparer (childBlock), this.directoryCluster);
if (!location.Valid)
throw new System.ArgumentException (); //throw new IOException ("Unable to delete directory because it is not empty");
fs.Delete (childBlock, directoryCluster, location.DirectoryIndex);
}
/// <summary>
/// Called to delete a child from a directory.
/// </summary>
/// <param name="child">The IVfsNode interface of the child.</param>
/// <param name="dentry">The DirectoryEntry of the child.</param>
/// <remarks>
/// This function deletes a child IVfsNode from a directory. If child is a directory, it will be empty
/// before this call is executed. It is recommended to include a debug sanity check though. If the file
/// system needs to know the name of the child to delete, it can retrieve it from <see cref="DirectoryEntry.Name"/>.
/// </remarks>
/// <exception cref="System.NotSupportedException">The object does not support removal this way. There's most likely an object specific API to remove this IVfsNode.</exception>
public override void Delete(IVfsNode child, DirectoryEntry dentry)
{
var fs = FileSystem as FatFileSystem;
uint targetCluster = (child as VfsDirectory).directoryCluster;
var location = fs.FindEntry(new Find.ByCluster(targetCluster), directoryCluster);
if (!location.IsValid)
throw new System.ArgumentException(); //throw new IOException ("Unable to delete directory because it is not empty");
fs.Delete(targetCluster, location.DirectorySector, location.DirectorySectorIndex);
}
/// <summary>
/// Releases the DirectoryEntry from the parent DirectoryEntry. This is *not* a delete operation.
/// </summary>
/// <remarks>
/// This function is used to remove a DirectoryEntry from the cache. Some (networked) file systems may want to use
/// this function to remove "known" directories from the lookup cache when they loose server connection.
/// </remarks>
public void Release()
{
// FIXME: Remove the entry from the parent and release it to the
// entry cache in the vfs service.
if (!System.Object.ReferenceEquals(this, Parent))
{
parent.RemoveChild(this);
}
inode = null;
name = null;
parent = null;
}
/// <summary>
/// Called to delete a child from a directory.
/// </summary>
/// <param name="child">The IVfsNode interface of the child.</param>
/// <param name="dentry">The DirectoryEntry of the child.</param>
/// <remarks>
/// This function deletes a child IVfsNode from a directory. If child is a directory, it will be empty
/// before this call is executed. It is recommended to include a debug sanity check though. If the file
/// system needs to know the name of the child to delete, it can retrieve it from <see cref="DirectoryEntry.Name"/>.
/// </remarks>
/// <exception cref="System.NotSupportedException">The object does not support removal this way. There's most likely an object specific API to remove this IVfsNode.</exception>
public override void Delete(IVfsNode child, DirectoryEntry dentry)
{
FatFileSystem fs = this.FileSystem as FatFileSystem;
uint targetCluster = (child as VfsDirectory).directoryCluster;
FatFileLocation location = fs.FindEntry(new Find.ByCluster(targetCluster), this.directoryCluster);
if (!location.Valid)
{
throw new System.ArgumentException(); //throw new IOException ("Unable to delete directory because it is not empty");
}
fs.Delete(targetCluster, location.DirectorySector, location.DirectorySectorIndex);
}
public override void Delete(IVfsNode child, DirectoryEntry dentry)
{
FAT fs = this.FileSystem as FAT;
uint childBlock = (child as VfsDirectory).directoryCluster;
FAT.DirectoryEntryLocation location = fs.FindEntry(new FAT.FatMatchClusterComparer(childBlock), this.directoryCluster);
if (!location.Valid)
{
throw new System.ArgumentException(); //throw new IOException ("Unable to delete directory because it is not empty");
}
fs.Delete(childBlock, directoryCluster, location.DirectoryIndex);
}
/// <summary>
/// Creates a new node in the (virtual) filesystem.
/// </summary>
/// <param name="path">The path to create.</param>
/// <param name="type">The type of the node to create.</param>
/// <param name="settings">Settings used to initialize the node.</param>
/// <param name="access">Requests the specified access modes on the created object.</param>
/// <param name="share">Requests the specified sharing settings on the object.</param>
/// <returns>The created filesystem object.</returns>
/// <remarks>
/// This function creates new nodes in the virtual filesystem. In contrast to *nix this call
/// creates all node types, e.g. files, directories, devices and more. Specific types may
/// require additional settings, which are specified in a settings object passed as the third
/// parameter.
/// </remarks>
public static object Create(string path, VfsNodeType type, object settings, FileAccess access, FileShare share)
{
// Retrieve the parent directory
DirectoryEntry parent = PathResolver.Resolve(rootNode, ref path, PathResolutionFlags.RetrieveParent);
// Check if the caller has write access in the directory
AccessCheck.Perform(parent, AccessMode.Write, AccessCheckFlags.None);
// Yes, we do have write access. Create the new vfs node
IVfsNode node = parent.Node.Create(path, type, settings);
// FIXME: Assert(null != node);
DirectoryEntry entry = DirectoryEntry.Allocate(parent, path, node);
// FIXME: Fix the permissions for this call. *nix does this using its bitmasks, Win32 through its huge CreateFile API.
return(node.Open(access, share));
}
/// <summary>
/// Called to delete a child from a directory.
/// </summary>
/// <param name="child">The IVfsNode interface of the child.</param>
/// <param name="dentry">The DirectoryEntry of the child.</param>
/// <remarks>
/// This function deletes a child IVfsNode from a directory. If child is a directory, it will be empty
/// before this call is executed. It is recommended to include a debug sanity check though. If the file
/// system needs to know the name of the child to delete, it can retrieve it from <see cref="DirectoryEntry.Name"/>.
/// </remarks>
/// <exception cref="System.NotSupportedException">The object does not support removal this way. There's most likely an object specific API to remove this IVfsNode.</exception>
public override void Delete(IVfsNode child, DirectoryEntry dentry)
{
// FIXME: throw new NotImplementedException();
}
/// <summary>
/// Called to delete a child from a directory.
/// </summary>
/// <param name="child">The IVfsNode interface of the child.</param>
/// <param name="dentry">The DirectoryEntry of the child.</param>
/// <remarks>
/// This function deletes a child IVfsNode from a directory. If child is a directory, it will be empty
/// before this call is executed. It is recommended to include a debug sanity check though. If the file
/// system needs to know the name of the child to delete, it can retrieve it from <see cref="DirectoryEntry.Name"/>.
/// </remarks>
/// <exception cref="System.NotSupportedException">The object does not support removal this way. There's most likely an object specific API to remove this IVfsNode.</exception>
public override void Delete(IVfsNode child, DirectoryEntry dentry)
{
// FIXME: throw new NotImplementedException();
}
/// <summary> /// Deletes the specified child. /// </summary> /// <param name="child">The child.</param> /// <param name="entry">The entry.</param> public abstract void Delete(IVfsNode child, DirectoryEntry entry);
/// <summary>
/// Called to delete a child from a directory.
/// </summary>
/// <param name="child">The IVfsNode interface of the child.</param>
/// <param name="dentry">The DirectoryEntry of the child.</param>
/// <remarks>
/// This function deletes a child IVfsNode from a directory. If child is a directory, it will be empty
/// before this call is executed. It is recommended to include a debug sanity check though. If the file
/// system needs to know the name of the child to delete, it can retrieve it from <see cref="DirectoryEntry.Name"/>.
/// </remarks>
/// <exception cref="System.NotSupportedException">The object does not support removal this way. There's most likely an object specific API to remove this IVfsNode.</exception>
public override void Delete(IVfsNode child, DirectoryEntry dentry)
{
throw new System.ArgumentException(); // Delete() method doesn't make sense here
}
/// <summary>
/// Allocates a vfs root directory entry.
/// </summary>
/// <param name="node">The vfs node, which corresponds to the root directory.</param>
/// <returns>The created directory entry.</returns>
/// <exception cref="System.ArgumentNullException">The specified node is invalid.</exception>
/// <remarks>
/// This method creates a directory entry, which has some special properties. The first one is, that
/// its parent is itself. This provides for the ability to cd .. on the root to stay on the root.
/// <para/>
/// The next ability is to create specialized root directories to isolate processes from the remainder
/// of the filesystem. Setting a root directory created using this method effectively limits the process
/// to access inside of the newly created namespace.
/// </remarks>
public static DirectoryEntry AllocateRoot(IVfsNode node)
{
#if VFS_NO_EXCEPTIONS
if (node == null)
throw new ArgumentNullException(@"node");
#endif // #if VFS_NO_EXCEPTIONS
DirectoryEntry result = new DirectoryEntry();
result.Setup(result, System.String.Empty, node);
return result;
}
/// <summary>
/// Allocates a new DirectoryEntry object for the given settings.
/// </summary>
/// <param name="parent">The parent directory entry.</param>
/// <param name="name">The name of the entry to create.</param>
/// <param name="node">The vfs node referenced by the directory entry.</param>
/// <returns>The allocated directory entry.</returns>
/// <exception cref="System.ArgumentNullException">If any one of the parameters is null.</exception>
/// <exception cref="System.ArgumentException">If the name is zero-length.</exception>
/// <remarks>
/// This method is used to control the DirectoryEntry allocation and maintain a cache of them. Also used to
/// prevent infinite name allocations.
/// </remarks>
public static DirectoryEntry Allocate(DirectoryEntry parent, string name, IVfsNode node)
{
//#if VFS_NO_EXCEPTIONS
if (parent == null)
throw new System.ArgumentNullException(@"parent");
if (name == null)
throw new System.ArgumentNullException(@"name");
if (node == null)
throw new System.ArgumentNullException(@"node");
if (name.Length == 0)
throw new System.ArgumentException(@"Invalid directory entry name."); // , @"name"
// FIXME: Add precondition check for invalid characters
// FIXME: Localize exception messages
//#endif // #if VFS_NO_EXCEPTIONS
DirectoryEntry directory = new DirectoryEntry();
directory.Setup(parent, name, node);
return directory;
}
/// <summary> /// Deletes the specified child. /// </summary> /// <param name="child">The child.</param> /// <param name="entry">The entry.</param> public abstract void Delete(IVfsNode child, DirectoryEntry entry);
public override void Delete(IVfsNode child, DirectoryEntry dentry)
{
// FIXME: Delete the symbolic link from the filesystem, after all names have been dropped.
throw new NotSupportedException();
}
/// <summary>
/// Releases the DirectoryEntry from the parent DirectoryEntry. This is *not* a delete operation.
/// </summary>
/// <remarks>
/// This function is used to remove a DirectoryEntry from the cache. Some (networked) file systems may want to use
/// this function to remove "known" directories from the lookup cache when they loose server connection.
/// </remarks>
public void Release()
{
// FIXME: Remove the entry from the parent and release it to the
// entry cache in the vfs service.
if (!System.Object.ReferenceEquals(this, Parent))
parent.RemoveChild(this);
inode = null;
name = null;
parent = null;
}
/// <summary>
/// Called to delete a child from a directory.
/// </summary>
/// <param name="child">The IVfsNode interface of the child.</param>
/// <param name="dentry">The DirectoryEntry of the child.</param>
/// <remarks>
/// This function deletes a child IVfsNode from a directory. If child is a directory, it will be empty
/// before this call is executed. It is recommended to include a debug sanity check though. If the file
/// system needs to know the name of the child to delete, it can retrieve it from <see cref="DirectoryEntry.Name"/>.
/// </remarks>
/// <exception cref="System.NotSupportedException">The object does not support removal this way. There's most likely an object specific API to remove this IVfsNode.</exception>
public override void Delete(IVfsNode child, DirectoryEntry dentry)
{
throw new System.ArgumentException(); // Delete() method doesn't make sense here
}
/// <summary>
///
/// </summary>
/// <param name="parent"></param>
/// <param name="name"></param>
/// <param name="node"></param>
private void Setup(DirectoryEntry parent, string name, IVfsNode node)
{
if (!System.Object.ReferenceEquals(this, parent))
parent.InsertChild(this);
this.parent = parent;
this.name = name;
inode = node;
}
/// <summary>
/// Performs an iterative lookup of the given path starting from the root and obeying to the specified flags.
/// </summary>
/// <param name="path">The path to lookup. This can be a relative or absolute path. Path.DirectorySeparatorChar or Path.AltDirectorySeparatorChar are valid delimiters.</param>
/// <param name="root">The root directory to start lookup from.</param>
/// <param name="flags">The lookup flags, which control the lookup process.</param>
/// <returns>The directory entry of the resolved path.</returns>
/// <exception cref="System.Security.SecurityException">The caller does not have access to the path or a component. For example the caller does not have the right to traverse the path.</exception>
/// <exception cref="System.IO.PathTooLongException">The path is too long to traverse. This can be the result of circular symbolic links in the path.</exception>
/// <exception cref="System.IO.FileNotFoundException">The path or a component was not found. This exception can be prevented by specifying PathResolutionFlags.DoNotThrowNotFoundException.</exception>
/// <exception cref="System.IO.DirectoryNotFoundException">A path component was not found. This exception can be prevented by specifying PathResolutionFlags.DoNotThrowNotFoundException.</exception>
/// <remarks>
/// This call may result in other exceptions not specified in the above list. Other exceptions can be thrown by IVfsNode implementations, which are visited during the traversal
/// process. For example a network file system node may throw an exception, if the server is unreachable.
/// </remarks>
private DirectoryEntry Resolve(ref string path, PathResolutionFlags flags)
{
// DirectoryNode entry found by stepping through the path
DirectoryEntry entry = null;
// Split the given path to its components
PathSplitter dirs = new PathSplitter(path);
// Determine the number of path components
int max = dirs.Length;
// Current path component
string item;
// Loop index
int index = 0;
// Perform an access check on the root directory
AccessCheck.Perform(currentDirectory, AccessMode.Traverse, AccessCheckFlags.None);
// Do not resolve the last name, if we want the parent directory.
if (PathResolutionFlags.RetrieveParent == (flags & PathResolutionFlags.RetrieveParent))
{
path = dirs[dirs.Length - 1];
max--;
}
// Check if this is an absolute path?
if (dirs[0].Length == 0)
{
// Yes, replace the current directory
currentDirectory = rootDirectory;
index++;
}
// Iterate over the remaining path components
while ((currentDirectory != null) && (index < max))
{
item = dirs[index];
entry = null;
if (currentDirectory.Node.NodeType == VfsNodeType.SymbolicLink)
{
SymbolicLinkNode link = (SymbolicLinkNode)currentDirectory.Node;
if (0 != depth--)
{
// The symlink stores a relative path, use it for a current relative lookup.
string target = link.Target;
// Build a new flags set for symlink lookups, as we do not want all of them.
PathResolutionFlags symflags = (flags & PathResolutionFlags.SymLinkLookupSafe);
entry = Resolve(ref target, symflags);
}
else
{
if (PathResolutionFlags.DoNotThrowNotFoundException != (PathResolutionFlags.DoNotThrowNotFoundException & flags))
{
// FIXME: Provide a MUI resource string for the exception
#if VFS_EXCEPTIONS
throw new PathTooLongException();
#endif // #if !VFS_EXCEPTIONS
}
}
}
else
{
// Pass the lookup to the DirectoryEntry (and ultimately to the inode itself.)
entry = currentDirectory.Lookup(item);
// If lookup in the directory entry failed, ask the real INode to perform the lookup.
if (entry == null)
{
IVfsNode node = currentDirectory.Node.Lookup(item);
if (node != null)
{
entry = DirectoryEntry.Allocate(currentDirectory, item, node);
}
}
}
// Increment the path component index
index++;
// Check if we have a new path component?
if ((entry == null) && (PathResolutionFlags.DoNotThrowNotFoundException != (PathResolutionFlags.DoNotThrowNotFoundException & flags)))
{
// FIXME: Move exception messages to MUI resources
#if VFS_EXCEPTIONS
if (index == max)
{
throw new FileNotFoundException(@"Failed to resolve the path.", path);
}
else
{
throw new DirectoryNotFoundException(@"Failed to resolve the path.");
}
#endif // #if VFS_EXCEPTIONS
}
// Set the current resolution directory
currentDirectory = entry;
// Check if the caller has traverse access to the directory
AccessCheck.Perform(currentDirectory, AccessMode.Traverse, AccessCheckFlags.None);
}
return(currentDirectory);
}
/// <summary>
///
/// </summary>
/// <param name="child"></param>
/// <param name="dentry"></param>
public override void Delete(IVfsNode child, DirectoryEntry dentry)
{
// FIXME: Delete the symbolic link from the filesystem, after all names have been dropped.
throw new System.NotSupportedException();
}
