public DirectoryEntry(FileSystemFAT fileSystem, long offset)
{
byte[] data = fileSystem.Store.GetBytes((ulong)offset, DIR_ENTRY_SIZE);
DIR_Name = ASCIIEncoding.ASCII.GetString(data, 0, 11);
DIR_Attr = (FATDirectoryAttributes)data[11];
DIR_NTRes = data[12];
DIR_CrtTimeTenth = data[13];
DIR_CrtTime = BitConverter.ToUInt16(data, 14);
DIR_CrtDate = BitConverter.ToUInt16(data, 16);
DIR_LstAccDate = BitConverter.ToUInt16(data, 18);
DIR_FstClusHI = BitConverter.ToUInt16(data, 20);
DIR_WrtTime = BitConverter.ToUInt16(data, 22);
DIR_WrtDate = BitConverter.ToUInt16(data, 24);
DIR_FstClusLO = BitConverter.ToUInt16(data, 26);
DIR_FileSize = BitConverter.ToUInt32(data, 28);
Free = data[0] == 0x0 || data[0] == 0x05 || data[0] == 0xE5;
Last = data[0] == 0x0;
string filename = DIR_Name.Substring(0, 8).Trim().ToLower();
string ext = DIR_Name.Substring(8).Trim().ToLower();
FileName = filename;
if (ext != "")
{
if ((Attributes & FATDirectoryAttributes.ATTR_VOLUME_ID) == 0)
{
FileName += ".";
}
FileName += ext;
}
Offset = fileSystem.GetDiskOffsetOfFATCluster(ClusterNum);
if (LongNameEntry)
{
LongName = string.Concat(Encoding.Unicode.GetString(data, 1, 10),
Encoding.Unicode.GetString(data, 14, 12),
Encoding.Unicode.GetString(data, 28, 4));
}
}
public override byte[] GetBytes(ulong _offset, ulong _length)
{
long offset = (long)_offset;
long length = (long)_length;
long currentCluster = FirstCluster;
lock (_clusterCache) {
byte[] res = new byte[length];
long resindex = 0;
// Find the first cluster we want to read.
while (offset >= FileSystem.BytesPerCluster && currentCluster >= 0)
{
currentCluster = GetNextCluster(currentCluster);
offset -= FileSystem.BytesPerCluster;
}
// Cache and retrieve the data for each cluster until we get all we need.
while (length > 0 && currentCluster >= 0)
{
// Cache the current cluster.
if (!_clusterCache.ContainsKey(currentCluster))
{
_clusterCache[currentCluster] = FileSystem.Store.GetBytes(
(ulong)FileSystem.GetDiskOffsetOfFATCluster(currentCluster),
(ulong)FileSystem.BytesPerCluster);
}
// Read the cached data.
long read = Math.Min(length, FileSystem.BytesPerCluster - offset);
Array.Copy(_clusterCache[currentCluster], offset, res, resindex, read);
offset = 0;
length -= read;
resindex += read;
currentCluster = GetNextCluster(currentCluster);
}
return(res);
}
}
private IEnumerable <DirectoryEntry> GetDirectoryEntries()
{
// read all directory entries
long pos = Offset;
long clusterStart = Offset;
long currentCluster = FirstCluster;
string longName = "";
List <DirectoryEntry> res = new List <DirectoryEntry>();
// check if this is pointing at the root dir and is obviously not supposed to be
if (_root || FirstCluster != FileSystem.RootCluster)
{
DirectoryEntry current = new DirectoryEntry(FileSystem, pos);
while (!current.Last)
{
if (current.LongNameEntry)
{
longName = current.LongName + longName;
}
else
{
if (!(_root && FileSystem.Type == PartitionType.FAT16) && current.Invalid)
{
// this is an invalid entry, so the whole directory is probably invalid
break;
}
if (longName.Contains("\0"))
{
longName = longName.Remove(longName.IndexOf("\0"));
}
if (longName != "")
{
current.FileName = longName;
}
//yield return current;
res.Add(current);
longName = "";
}
if (_root && FileSystem.Type == PartitionType.FAT16 &&
pos - clusterStart >= FileSystem.RootEntryCount * DIR_ENTRY_SIZE)
{
break;
}
else if ((_root && FileSystem.Type == PartitionType.FAT16) ||
pos - clusterStart < FileSystem.BytesPerCluster)
{
pos += DIR_ENTRY_SIZE;
}
else
{
// check the FAT
currentCluster = GetNextCluster(currentCluster);
if (currentCluster < 0)
{
break;
}
pos = clusterStart = FileSystem.GetDiskOffsetOfFATCluster(currentCluster);
}
current = new DirectoryEntry(FileSystem, pos);
}
}
return(res);
}