private DfsDirectoryEntry FindDirectory(DfsDirectoryEntry baseDir, string name, uint flags)
{
if (baseDir.FilePointer == 0)
{
return(null);
}
DfsDirectoryEntry currentDir = new DfsDirectoryEntry(FindSector(baseDir.FilePointer));
do
{
// check flags and path
if (((currentDir.Flags & DfsDirectoryEntry.FLAG_MASK) == flags) && (currentDir.Path.Equals(name)))
{
return(currentDir);
}
// no next enty? -> done
if (currentDir.NextEntry == 0)
{
break;
}
currentDir = new DfsDirectoryEntry(FindSector(currentDir.NextEntry));
} while (true);
// not found
return(null);
}
private void WalkDirectory(DfsDirectoryEntry dir, List <DfsSector> sectors)
{
do
{
var sector = FindSector(dir.Offset);
sectors.Remove(sector);
if (dir.FilePointer != 0)
{
sector = FindSector(dir.FilePointer);
var entry = new DfsDirectoryEntry(sector);
if ((entry.Flags & DfsDirectoryEntry.FLAG_DIR) != 0)
{
WalkDirectory(entry, sectors);
}
else
//if ((entry.Flags & DfsDirectoryEntry.FLAG_FILE) != 0)
{
sectors.Remove(sector);
WalkFile(entry, sectors);
}
}
if (dir.NextEntry == 0)
{
break;
}
dir = new DfsDirectoryEntry(FindSector(dir.NextEntry));
} while (true);
}
public DfsFileStream(DragonFs fs, DfsDirectoryEntry root, FileAccess access)
{
_Fs = fs;
_Root = root;
if (root.FilePointer != 0)
{
if ((access == FileAccess.Write) || (access == FileAccess.ReadWrite))
{
throw new NotSupportedException("Writing an existing file is not supported");
}
// Create MemoryStream from existing data
_MemStream = new MemoryStream((int)(_Root.Flags & ~DfsDirectoryEntry.FLAG_MASK));
int remainingBytes = (int)Length;
uint offset = root.FilePointer;
while (remainingBytes > 0)
{
// Fetch a sector and write to the stream
DfsSector sector = _Fs.FindSector(offset);
int sectorBytes = (int)DfsSector.SECTOR_SIZE;
if (sectorBytes >= remainingBytes)
{
sectorBytes = remainingBytes;
}
_MemStream.Write(sector.Buffer, 0, sectorBytes);
remainingBytes -= sectorBytes;
offset += DfsSector.SECTOR_SIZE;
}
_MemStream.Seek(0, SeekOrigin.Begin);
}
else
{
if (access == FileAccess.Read)
{
throw new NotSupportedException("Cannot read file without content");
}
// Create MemoryStream for all file operations
_MemStream = new MemoryStream();
}
switch (access)
{
case FileAccess.Read:
_CanRead = true;
break;
case FileAccess.ReadWrite:
_CanRead = true;
_CanWrite = true;
break;
case FileAccess.Write:
_CanWrite = true;
break;
}
}
void AppendDirectoryEntry(DfsDirectoryEntry directoryEntry, uint offset)
{
while (directoryEntry.NextEntry != 0)
{
directoryEntry = new DfsDirectoryEntry(FindSector(directoryEntry.NextEntry));
}
directoryEntry.NextEntry = offset;
}
private DfsDirectoryEntry CreateFileEntry(string path)
{
DfsDirectoryEntry currentDir;
if (path[0] == '/')
{
currentDir = _RootDirectory;
}
else
{
currentDir = _CurrentDirectory;
}
string[] dirs = path.Split(new char[] { '/' }, StringSplitOptions.RemoveEmptyEntries);
for (int i = 0; i < dirs.Length; i++)
{
string searchDir = dirs[i];
DfsDirectoryEntry foundDir;
if (i == dirs.Length - 1)
{
foundDir = FindDirectory(currentDir, searchDir, DfsDirectoryEntry.FLAG_FILE);
}
else
{
foundDir = FindDirectory(currentDir, searchDir, DfsDirectoryEntry.FLAG_DIR);
}
if (foundDir == null)
{
// Create the new Directory and put it at the end
foundDir = NewDirectoryEntry();
if (i == dirs.Length - 1)
{
foundDir.Flags = DfsDirectoryEntry.FLAG_FILE;
}
else
{
foundDir.Flags = DfsDirectoryEntry.FLAG_DIR;
}
foundDir.Path = searchDir;
if (currentDir.FilePointer == 0)
{
currentDir.FilePointer = foundDir.Offset;
}
else
{
currentDir = new DfsDirectoryEntry(FindSector(currentDir.FilePointer));
AppendDirectoryEntry(currentDir, foundDir.Offset);
}
}
currentDir = foundDir;
}
return(currentDir);
}
private void WalkFile(DfsDirectoryEntry fileEntry, List <DfsSector> sectors)
{
int fileSize = (int)(fileEntry.Flags & ~DfsDirectoryEntry.FLAG_MASK);
uint offset = 0;
do
{
var sector = FindSector(fileEntry.FilePointer + offset);
sectors.Remove(sector);
offset += DfsSector.SECTOR_SIZE;
} while (offset < fileSize);
}
public DragonFs()
{
DfsDirectoryEntry fsRoot = new DfsDirectoryEntry(NewSector())
{
Flags = ROOT_FLAGS,
NextEntry = ROOT_NEXTENTRY,
Path = ROOT_PATH
};
// build a dummy root with a valid file pointer
// the real first sectors file pointer is always 0
// but this one can be modified
_RootDirectory = new DfsDirectoryEntry(new DfsSector(0));
_RootDirectory.Flags = DfsDirectoryEntry.FLAG_DIR;
_CurrentDirectory = _RootDirectory;
}
public DfsFileStream OpenFile(string path, FileAccess access)
{
DfsDirectoryEntry directoryEntry = FindDirectory(path, DfsDirectoryEntry.FLAG_FILE);
if (directoryEntry == null)
{
if (access == FileAccess.Read)
{
throw new FileNotFoundException();
}
else
{
directoryEntry = CreateFileEntry(path);
}
}
return(new DfsFileStream(this, directoryEntry, access));
}
public static DragonFs CreateFromStream(Stream source)
{
DragonFs newFs = new DragonFs();
DfsSector sector = new DfsSector(0);
source.Read(sector.Buffer, 0, (int)DfsSector.SECTOR_SIZE);
DfsDirectoryEntry root = new DfsDirectoryEntry(sector);
bool checkValid = true;
if ((root.Flags != ROOT_FLAGS) || (root.NextEntry != ROOT_NEXTENTRY))
{
checkValid = false;
}
else
{
// Check DFS version string
if (!root.Path.Equals(DragonFs.ROOT_PATH))
{
checkValid = false;
}
}
if (checkValid == false)
{
throw new ArgumentException("source", "The stream does not contain a valid DFS 2.0 image");
}
while (source.Position != source.Length)
{
sector = newFs.NewSector();
source.Read(sector.Buffer, 0, (int)DfsSector.SECTOR_SIZE);
}
// The virtual root directory entry needs to point to the first sector
// TODO: Can this be done better?
newFs._RootDirectory.FilePointer = DfsSector.SECTOR_SIZE;
return(newFs);
}
public void CreateDirectory(string path)
{
DfsDirectoryEntry currentDir;
if (path[0] == '/')
{
currentDir = _RootDirectory;
}
else
{
currentDir = _CurrentDirectory;
}
string[] dirs = path.Split(new char[] { '/' }, StringSplitOptions.RemoveEmptyEntries);
foreach (string searchDir in dirs)
{
DfsDirectoryEntry foundDir = FindDirectory(currentDir, searchDir, DfsDirectoryEntry.FLAG_DIR);
if (foundDir == null)
{
// Create the new Directory and put it at the end
foundDir = NewDirectoryEntry();
foundDir.Flags = DfsDirectoryEntry.FLAG_DIR;
foundDir.Path = searchDir;
if (currentDir.FilePointer == 0)
{
currentDir.FilePointer = foundDir.Offset;
}
else
{
currentDir = new DfsDirectoryEntry(FindSector(currentDir.FilePointer));
AppendDirectoryEntry(currentDir, foundDir.Offset);
}
}
currentDir = foundDir;
}
}
