/// <summary>
/// reads an OnDiscAdress from the index.
/// </summary>
/// <param name="NumberOfAdress">is the number of the OnDiscAdress to be read</param>
/// <returns></returns>
public OnDiscAdress ReadOnDiscAdress(long NumberOfAdress)
{
//byte[] Readin;
lock (DatabaseIndexFile)
{
// check if this is even possible...
if (DatabaseIndexFile.Length <= NumberOfAdress * 33)
{
return(null);
}
// seek to the multiple of NumberOfAdress
DatabaseIndexFile.Seek(NumberOfAdress * 33, SeekOrigin.Begin);
byte[] _SerializedData;
OnDiscAdress _deserializedAdress;
try
{
_SerializedData = new byte[33];
// todo: maybe a read cache might be great, to read more bytes sequential
DatabaseIndexFile.Read(_SerializedData, 0, 33);
_deserializedAdress = new OnDiscAdress();
_reader.Data = _SerializedData;
_deserializedAdress.Deserialize(ref _reader);
return(_deserializedAdress);
}
catch (Exception)
{
return(null);
}
}
}
/// <summary>
/// writes a new chunk of data to the disk (and index)
/// </summary>
/// <param name="Data">the byte array with the data</param>
public void Write(byte[] Data)
{
// write the data to the database file
OnDiscAdress adress = WriteToDatabase(Data);
// and the adress to the index
WriteToIndex(adress);
}
public byte[] ReadData(OnDiscAdress Adress)
{
byte[] Readin;
lock (DatabaseFile)
{
// seek to the position
DatabaseFile.Seek(Adress.Start, SeekOrigin.Begin);
Readin = new byte[Adress.End - Adress.Start];
// read it in
DatabaseFile.Read(Readin, 0, Readin.Length);
}
return Readin;
}
public byte[] ReadData(OnDiscAdress Adress)
{
byte[] Readin;
lock (DatabaseFile)
{
// seek to the position
DatabaseFile.Seek(Adress.Start, SeekOrigin.Begin);
Readin = new byte[Adress.End - Adress.Start];
// read it in
DatabaseFile.Read(Readin, 0, Readin.Length);
}
return(Readin);
}
private void WriteToIndex(OnDiscAdress Adresspattern)
{
lock (DatabaseIndexFile)
{
// seek to the end...
DatabaseIndexFile.Seek(DatabaseIndexFile.Length, SeekOrigin.Begin);
// re-use the writer
_writer.ResetBuffer();
// serialize the index...
byte[] ToWrite = Adresspattern.SerializeAligned(ref _writer);
DatabaseIndexFile.Write(ToWrite, 0, ToWrite.Length);
if (FlushOnWrite)
{
DatabaseIndexFile.Flush();
}
}
}
private OnDiscAdress WriteToDatabase(byte[] ToWrite)
{
OnDiscAdress OutputAdress = new OnDiscAdress();
lock (DatabaseFile)
{
// seek to the end...
DatabaseFile.Seek(DatabaseFile.Length, SeekOrigin.Begin);
OutputAdress.Start = DatabaseFile.Position;
DatabaseFile.Write(ToWrite, 0, ToWrite.Length);
OutputAdress.End = DatabaseFile.Position;
if (FlushOnWrite)
{
DatabaseFile.Flush();
}
}
return(OutputAdress);
}
private void WriteToIndex(OnDiscAdress Adresspattern)
{
lock (DatabaseIndexFile)
{
// seek to the end...
DatabaseIndexFile.Seek(DatabaseIndexFile.Length, SeekOrigin.Begin);
// re-use the writer
_writer.ResetBuffer();
// serialize the index...
byte[] ToWrite = Adresspattern.SerializeAligned(ref _writer);
DatabaseIndexFile.Write(ToWrite, 0, ToWrite.Length);
if (FlushOnWrite)
DatabaseIndexFile.Flush();
}
}
private OnDiscAdress WriteToDatabase(byte[] ToWrite)
{
OnDiscAdress OutputAdress = new OnDiscAdress();
lock (DatabaseFile)
{
// seek to the end...
DatabaseFile.Seek(DatabaseFile.Length, SeekOrigin.Begin);
OutputAdress.Start = DatabaseFile.Position;
DatabaseFile.Write(ToWrite, 0, ToWrite.Length);
OutputAdress.End = DatabaseFile.Position;
if (FlushOnWrite)
DatabaseFile.Flush();
}
return OutputAdress;
}
/// <summary>
/// reads an OnDiscAdress from the index.
/// </summary>
/// <param name="NumberOfAdress">is the number of the OnDiscAdress to be read</param>
/// <returns></returns>
public OnDiscAdress ReadOnDiscAdress(long NumberOfAdress)
{
byte[] Readin;
lock (DatabaseIndexFile)
{
// check if this is even possible...
if (DatabaseIndexFile.Length <= NumberOfAdress * 33)
return null;
// seek to the multiple of NumberOfAdress
DatabaseIndexFile.Seek(NumberOfAdress * 33, SeekOrigin.Begin);
byte[] _SerializedData;
OnDiscAdress _deserializedAdress;
try
{
_SerializedData = new byte[33];
// todo: maybe a read cache might be great, to read more bytes sequential
DatabaseIndexFile.Read(_SerializedData, 0, 33);
_deserializedAdress = new OnDiscAdress();
_reader.Data = _SerializedData;
_deserializedAdress.Deserialize(ref _reader);
return _deserializedAdress;
}
catch (Exception)
{
return null;
}
}
}
