/// <summary>
/// Write a sector containing file data to the disk
/// </summary>
/// <param name="sector"></param>
/// <param name="fileSector"></param>
public override void WriteFileSector(int sector, FileSector fileSector)
{
var sectorData = new byte[128];
Array.Clear(sectorData, 0, 128);
Array.Copy(fileSector.Data, sectorData, fileSector.ByteCount);
sectorData[125] = (byte)((fileSector.NextSector & 0xff00) >> 8);
sectorData[126] = (byte)(fileSector.NextSector & 0xff);
sectorData[127] = (byte)fileSector.ByteCount;
WriteSector(sector, sectorData);
}
/// <summary>
/// Read a sector containing file data from the disk
/// </summary>
/// <param name="sector"></param>
/// <returns></returns>
public override FileSector ReadFileSector(int sector)
{
var fileSector = new FileSector();
fileSector.Data = new byte[125];
var sec = ReadSector(sector);
fileSector.FileHandle = -1;
fileSector.NextSector = (sec[125] << 8) + sec[126];
fileSector.ByteCount = sec[127] & 0x7F;
fileSector.Sector = sector;
for (int i = 0; i < 125; i++) fileSector.Data[i] = sec[i];
return fileSector;
}
/// <summary>
/// Read a sector containing file data from the disk
/// </summary>
/// <param name="sector"></param>
/// <returns></returns>
public virtual FileSector ReadFileSector(int sector)
{
var fileSector = new FileSector();
fileSector.Data = new byte[125];
var sec = ReadSector(sector);
fileSector.Sector = sector;
fileSector.FileHandle = (sec[125] & 0xfc) >> 2;
fileSector.NextSector = ((sec[125] & 0x3) << 8) + sec[126];
fileSector.ByteCount = sec[127] & 0x7F;
for (int i = 0; i < 125; i++) fileSector.Data[i] = sec[i];
return fileSector;
}
/// -----------------------------------------------------------------------------
/// <summary>
/// Adds a file to the disk
/// </summary>
/// <param name="Filename">Name of file being added</param>
/// <param name="data">File data</param>
/// <remarks>
/// </remarks>
/// -----------------------------------------------------------------------------
public override void AddFile(string Filename, byte[] data)
{
DirectoryEntry entry;
int curSector;
int nextSector;
int len;
Attach();
//Be sure filename is valid
if (!ValidFileName(Filename))
{
throw new InvalidFileNameException();
}
//If file already exists, delete it
entry = FindDirectoryEntry(Filename);
if (entry != null)
{
DeleteFile(Filename);
}
// Check for disk space
int dataLength = 0;
if (data != null) dataLength = data.Length;
int requiredSectors = (dataLength / 125);
if (dataLength % 125 > 0) requiredSectors += 1;
if (requiredSectors == 0) requiredSectors = 1; // Files are always at least one sector
if (requiredSectors > UnusedSectors()) throw new InsufficientDiskSpaceException();
// Find open directory entry
entry = GetOpenEntry();
if (entry == null) throw new DirectoryFullException();
entry.FileName = Filename;
entry.Deleted = false;
entry.EntryInUse = true;
entry.Locked = false;
entry.OpenForOutput = false;
entry.StartSector = sectorMap.GetNextAvailableSector();
entry.NumSectors = requiredSectors;
curSector = entry.StartSector;
for (int i = 0; i <= requiredSectors - 1; i++)
{
if ((dataLength - (i * 125)) <= 125)
{
len = dataLength - (i * 125);
nextSector = 0;
}
else
{
len = 125;
nextSector = sectorMap.GetNextAvailableSector();
}
var fileSec = new FileSector();
fileSec.FileHandle = entry.FileNumber;
fileSec.NextSector = nextSector;
fileSec.ByteCount = len;
fileSec.Data = new byte[125];
if (data != null) Array.Copy(data, i * 125, fileSec.Data, 0, len);
WriteFileSector(curSector, fileSec);
curSector = nextSector;
}
WriteDirectoryEntry(entry);
WriteSectorMap();
//Refresh the directory
ReadDirectory();
UpdateUnusedSectors();
}
/// <summary>
/// Write a sector containing file data to the disk
/// </summary>
/// <param name="sector"></param>
/// <param name="fileSector"></param>
public virtual void WriteFileSector(int sector, FileSector fileSector)
{
var sectorData = new byte[128];
Array.Clear(sectorData, 0, 128);
Array.Copy(fileSector.Data, sectorData, fileSector.ByteCount);
var b = (byte)(fileSector.FileHandle << 2);
b |= (byte)((fileSector.NextSector & 0x300) >> 8);
sectorData[125] = b;
sectorData[126] = (byte)(fileSector.NextSector & 0xff);
sectorData[127] = (byte)fileSector.ByteCount;
WriteSector(sector, sectorData);
}
