/// <summary>
/// 创建一个新目录
/// </summary>
/// <param name="vfs"></param>
/// <returns></returns>
public static INodeDirectory Create(VFSCore vfs)
{
INode inode = vfs.AllocateINode(1, 2333);
INodeDirectory t = new INodeDirectory(vfs, inode);
t.AddSelf();
return t;
}
/// <summary>
/// 根据 inode 建立 INodeDirectory
/// </summary>
/// <param name="vfs"></param>
/// <param name="inode"></param>
/// <returns></returns>
public static INodeDirectory Load(VFSCore vfs, INode inode)
{
INodeDirectory t = new INodeDirectory(vfs, inode);
t.Load();
return(t);
}
/// <summary>
/// 创建一个新目录
/// </summary>
/// <param name="vfs"></param>
/// <returns></returns>
public static INodeDirectory Create(VFSCore vfs)
{
INode inode = vfs.AllocateINode(1, 2333);
INodeDirectory t = new INodeDirectory(vfs, inode);
t.AddSelf();
return(t);
}
/// <summary>
/// 格式化存储介质
/// </summary>
/// <param name="inodeCapacity">inode 数量</param>
/// <param name="blockSizeKByte">block 大小（KB），必须为 1，2，4，8 中的一个</param>
public void Format(UInt32 inodeCapacity, UInt16 blockSizeKByte = 4)
{
if (inodeCapacity < 32)
{
throw new Exception("inode 至少为 32 个");
}
if (!new int[] { 1, 2, 4, 8 }.Contains(blockSizeKByte))
{
throw new Exception("block 大小只能为 1KB, 2KB, 4KB 或 8KB");
}
uint offset = 0;
offset += (uint)Utils.GetStructSize <_SuperBlock>();
offset += (inodeCapacity / 32 + 1) * 4;
offset += (uint)Utils.GetStructSize <_INode>() * inodeCapacity;
if (offset > deviceSize)
{
throw new Exception("inode 数量过大，结构超出存储介质最大空间");
}
// 可留给数据块位图和数据块区的大小
uint sizeRemain = deviceSize - offset;
// 全部留给数据块，可以有多少个数据块
uint blockCapacity = sizeRemain / blockSizeKByte >> 10;
if (blockCapacity < 128)
{
throw new Exception("磁盘空间太小，至少要可以容纳 128 个块");
}
// 删除 (blockCapacity / 32 + 1) * 4 大小的数据块，留作数据块位图使用
blockCapacity -= ((blockCapacity / 32 + 1) * 4 / blockSizeKByte) + 1;
// 初始化 superBlock
superBlock = SuperBlock.Create(this, inodeCapacity, (UInt16)(blockSizeKByte << 10), blockCapacity);
// 单个 inode BitVector 可容纳 32 位
inodeBitmaps = new UInt32[inodeCapacity / 32 + 1];
device.WriteArray(superBlock.pInodeBitVectors, inodeBitmaps, 0, inodeBitmaps.Length);
// 单个 block BitVector 可容纳 32 位
blockBitmaps = new UInt32[blockCapacity / 32 + 1];
device.WriteArray(superBlock.pBlockBitVectors, blockBitmaps, 0, blockBitmaps.Length);
// 写入根目录
INodeDirectory.Create(this);
Console.WriteLine("格式化成功。");
Console.WriteLine("SuperBlock: {0}", superBlock.ToString());
}
/// <summary>
/// 删除一个目录项
/// </summary>
/// <param name="name"></param>
/// <returns></returns>
public Boolean Delete(String name)
{
if (!Contains(name))
{
return(false);
}
if (name == "." || name == "..")
{
return(false);
}
var inodeIndex = entries[name];
INode inode = INode.Load(vfs, inodeIndex);
if (inode.IsDirectory())
{
// 删除非空目录项:递归删除
INodeDirectory id = INodeDirectory.Load(vfs, inodeIndex);
if (id.Size() > 2)
{
var l = id.List();
foreach (var pair in l)
{
id.Delete(pair.Key);
}
}
}
inode.data.linkCount--;
if (inode.data.linkCount == 0)
{
inode.Resize(0);
vfs.DeAllocateINode(inode.index);
}
else
{
inode.Save();
}
entries.Remove(name);
Save();
return(true);
}
public Directory(VFSCore vfs, String path)
{
this.vfs = vfs;
if (!path.EndsWith("/"))
{
path += "/";
}
this.path = path;
dir = INodeDirectory.Resolve(vfs, path);
if (dir == null)
{
throw new Exception("无效路径");
}
}
public Directory(VFSCore vfs, String path)
{
this.vfs = vfs;
if (!path.EndsWith("/"))
{
path += "/";
}
this.path = path;
dir = INodeDirectory.Resolve(vfs, path);
if (dir == null)
{
throw new Exception("无效路径");
}
}
/// <summary>
/// 添加一个目录目录项
/// </summary>
/// <param name="name"></param>
/// <param name="dir"></param>
/// <returns></returns>
public Boolean Add(String name, INodeDirectory dir)
{
if (Contains(name))
{
return(false);
}
if (dir.Contains(".."))
{
return(false);
}
entries[name] = dir.inode.index;
dir.inode.data.linkCount++;
dir.inode.Save();
dir.AddParent(inode.index);
Save();
return(true);
}
/// <summary>
/// 根据路径解析目录，路径必须以 / 结尾
/// </summary>
/// <param name="path"></param>
/// <returns></returns>
public static INodeDirectory Resolve(VFSCore vfs, String path)
{
INodeDirectory root = Load(vfs, 0);
var pathCom = path.Split('/');
var node = root;
for (var i = 1; i < pathCom.Length - 1; ++i)
{
if (node.Contains(pathCom[i]) && INode.Load(vfs, node.Find(pathCom[i])).IsDirectory())
{
node = Load(vfs, node.Find(pathCom[i]));
}
else
{
return(null);
}
}
return(node);
}
/// <summary>
/// 根据 inode 建立 INodeDirectory
/// </summary>
/// <param name="vfs"></param>
/// <param name="inode"></param>
/// <returns></returns>
public static INodeDirectory Load(VFSCore vfs, INode inode)
{
INodeDirectory t = new INodeDirectory(vfs, inode);
t.Load();
return t;
}
/// <summary>
/// 添加一个目录目录项
/// </summary>
/// <param name="name"></param>
/// <param name="dir"></param>
/// <returns></returns>
public Boolean Add(String name, INodeDirectory dir)
{
if (Contains(name))
{
return false;
}
if (dir.Contains(".."))
{
return false;
}
entries[name] = dir.inode.index;
dir.inode.data.linkCount++;
dir.inode.Save();
dir.AddParent(inode.index);
Save();
return true;
}
public File(VFSCore vfs, String path, FileMode fileMode)
{
this.vfs = vfs;
var directory = VFS.GetPathDirectory(path);
var name = VFS.GetPathName(path);
VFS.AssertNameValid(name);
INodeDirectory dir = INodeDirectory.Resolve(vfs, directory);
if (dir == null)
{
throw new Exception("无法访问目录");
}
switch (fileMode)
{
case FileMode.CreateNew:
if (dir.Contains(name))
{
throw new Exception("文件已存在");
}
CreateFile(dir, name);
break;
case FileMode.Create:
if (dir.Contains(name))
{
OpenFile(dir, name);
inode.Resize(0);
}
else
{
CreateFile(dir, name);
}
break;
case FileMode.Open:
if (!dir.Contains(name))
{
throw new Exception("文件未找到");
}
OpenFile(dir, name);
break;
case FileMode.OpenOrCreate:
if (dir.Contains(name))
{
OpenFile(dir, name);
}
else
{
CreateFile(dir, name);
}
break;
case FileMode.Truncate:
if (!dir.Contains(name))
{
throw new Exception("文件未找到");
}
OpenFile(dir, name);
inode.Resize(0);
break;
case FileMode.Append:
if (!dir.Contains(name))
{
CreateFile(dir, name);
}
else
{
OpenFile(dir, name);
position = inode.data.sizeByte;
}
break;
default:
throw new ArgumentException();
}
}
/// <summary>
/// 通过打开现有文件来初始化该类
/// </summary>
/// <param name="dir"></param>
/// <param name="name"></param>
private void OpenFile(INodeDirectory dir, String name)
{
inode = INode.Load(vfs, dir.Find(name));
}
/// <summary>
/// 通过创建一个新文件来初始化该类
/// </summary>
/// <param name="vfs"></param>
/// <param name="name"></param>
/// <param name="dir"></param>
private void CreateFile(INodeDirectory dir, String name)
{
inode = vfs.AllocateINode(0, 2333);
dir.Add(name, inode);
}
/// <summary>
/// 通过打开现有文件来初始化该类
/// </summary>
/// <param name="dir"></param>
/// <param name="name"></param>
private void OpenFile(INodeDirectory dir, String name)
{
inode = INode.Load(vfs, dir.Find(name));
}
/// <summary>
/// 通过创建一个新文件来初始化该类
/// </summary>
/// <param name="vfs"></param>
/// <param name="name"></param>
/// <param name="dir"></param>
private void CreateFile(INodeDirectory dir, String name)
{
inode = vfs.AllocateINode(0, 2333);
dir.Add(name, inode);
}