//
// ReadDirectoryHeader:
// reads a directory header from the filesystem. a directory
// header contains information about a directory. mostly this
// is just information about the next and previous blocks in this
// directory
//
// arguments:
// 1) CoreDirectoryHeader *de (OUT): a pointer to an allocated CoreDirectoryHeader
// object. this will be initialized with the data read from the disc
//
// return value:
// true on success, false otherwise
//
public bool ReadDirectoryHeader(ref CoreDirectoryHeader dh)
{
UInt32 bytesRead = 0;
bool ret;
byte[] buffer = new byte[CoreDirectoryHeaderConsts.DirectoryHeaderSize];
GCHandle handle = GCHandle.Alloc(buffer, GCHandleType.Pinned);
ret = _fileReader.Read(handle.AddrOfPinnedObject(), CoreDirectoryHeaderConsts.DirectoryHeaderSize, ref bytesRead);
if (!ret)
{
return(false);
}
dh = (CoreDirectoryHeader)Marshal.PtrToStructure(handle.AddrOfPinnedObject(), typeof(CoreDirectoryHeader));
handle.Free();
//
// make all relevant fields little endian
//
EndianSwap(ref dh.nextBlock);
EndianSwap(ref dh.prevBlock);
EndianSwap(ref dh.flags);
EndianSwap(ref dh.unusedOffset);
EndianSwap(ref dh.directoryOffset);
return(true);
}
internal Directory(UInt32 firstByte, FileSystem fileSystem, CoreDirectoryHeader coreDirectoryHeader, CoreDirectoryEntry?coreDirectoryEntry, Directory parentDirectory)
{
_firstByte = firstByte;
_coreDirectoryHeader = coreDirectoryHeader;
_coreDirectoryEntry = coreDirectoryEntry;
_fileSystem = fileSystem;
_parentDirectory = parentDirectory;
}
private List <IItem> FetchItems()
{
var returnValue = new List <IItem>();
var coreFileSystem = _fileSystem.CoreFileSystem;
var coreDirectoryEntry = new CoreDirectoryEntry();
var coreDirectory = new CoreDirectory(coreFileSystem);
coreDirectory.SetCoreDirectoryHeader(_coreDirectoryHeader);
coreFileSystem.FileReader.SeekToByte(_firstByte, false);
coreFileSystem.FileReader.SeekToByte(_coreDirectoryHeader.directoryOffset, true);
var currentByte = coreFileSystem.FileReader.CurrentByte;
while (coreDirectory.EnumerateDirectory(ref coreDirectoryEntry))
{
IItem newItem;
UInt32 itemType = (coreDirectoryEntry.flags & CoreDirectoryEntryConsts.DirectoryEntryTypeMask);
if (itemType == CoreDirectoryEntryConsts.DirectoryEntryTypeFolder)
{
//////////////////////////
// Seek to and read the folder header now!
var returnByte = coreFileSystem.FileReader.CurrentByte;
coreFileSystem.SeekToBlock(coreDirectoryEntry.FirstCopy, false);
var referencedByte = coreFileSystem.FileReader.CurrentByte;
var coreDirectoryHeader = new CoreDirectoryHeader();
coreFileSystem.ReadDirectoryHeader(ref coreDirectoryHeader);
// Go back into the enumeration position.
coreFileSystem.SeekToByte(returnByte, false);
//////////////////////////
// Now we're ready to create the directory entry.
newItem = new Directory(referencedByte, _fileSystem, coreDirectoryHeader, coreDirectoryEntry, this);
}
else
{
newItem = new File(currentByte, _fileSystem, coreDirectoryEntry, this);
}
returnValue.Add(newItem);
currentByte = coreFileSystem.FileReader.CurrentByte;
}
return(returnValue);
}
public FileSystem(IFileReader fileReader)
{
_fileReader = fileReader;
_fileReader.SeekToByte(0, false);
_coreFileSystem = new CoreFileSystem(_fileReader);
var coreVolumeHeader = new CoreVolumeHeader();
var coreDirectoryHeader = new CoreDirectoryHeader();
_coreFileSystem.ReadVolumeHeader(ref coreVolumeHeader);
_coreFileSystem.SeekToBlock(coreVolumeHeader.FirstCopy, false);
uint directoryHeaderStart = _coreFileSystem.FileReader.CurrentByte;
_coreFileSystem.ReadDirectoryHeader(ref coreDirectoryHeader);
_rootVolumeHeader = new VolumeHeader(coreVolumeHeader);
_rootDirectory = new Directory(directoryHeaderStart, this, coreDirectoryHeader, null, null);
}
public void SetCoreDirectoryHeader(CoreDirectoryHeader header)
{
_coreDirectoryHeader = header;
}
