private static string GetSectionLabel(TapDataBlock dataBlock)
{
string sectionLabel = null;
switch (dataBlock.Type)
{
case TapDataBlockType.StandardHeader:
TapHeader header = (TapHeader)dataBlock;
switch (header.HeaderType)
{
case TapHeaderType.ProgramHeader:
ProgramHeader programHeader = (ProgramHeader)header;
sectionLabel = "Program header : " + programHeader.GetProperties();
break;
case TapHeaderType.ByteArrayHeader:
ByteArrayHeader byteArrayHeader = (ByteArrayHeader)header;
sectionLabel = "Byte array header : " + byteArrayHeader.GetProperties();
break;
case TapHeaderType.StringArrayHeader:
AlphanumArrayHeader stringArrayHeader = (AlphanumArrayHeader)header;
sectionLabel = "String array header : " + stringArrayHeader.GetProperties();
break;
case TapHeaderType.NumberArrayHeader:
AlphanumArrayHeader numberArrayHeader = (AlphanumArrayHeader)header;
sectionLabel = "Number array header : " + numberArrayHeader.GetProperties();
break;
}
break;
case TapDataBlockType.StandardDataBlock:
sectionLabel = "Standard data block : " + dataBlock.DataLength + " bytes";
break;
case TapDataBlockType.CustomDataBlock:
sectionLabel = "Custom data block : " + dataBlock.DataLength + " bytes";
break;
case TapDataBlockType.FragmentedDataBlock:
sectionLabel = "Fragmented data block : " + dataBlock.DataLength + " bytes";
break;
}
if (dataBlock.HasInvalidChecksum)
{
sectionLabel += " [invalid checksum]";
}
return(sectionLabel);
}
internal static TapDataBlock ReadTapDataBlock(BinaryReader fileReader, int dataLengthBytesCount)
{
// Data block length
int dataLength = fileReader.ReadUInt16();
if (dataLengthBytesCount == 3)
{
dataLength += (fileReader.ReadByte() * 256 * 256);
}
// Read tape data block
byte[] tapeData = null;
if (dataLength > 0)
{
tapeData = fileReader.ReadBytes(dataLength);
}
TapDataBlock tapDataBlock = null;
if (dataLength > 0)
{
byte flag = tapeData[0];
// Standard header
if (flag == 0 && dataLength == 19)
{
using (BinaryReader headerReader = new BinaryReader(new MemoryStream(tapeData)))
{
headerReader.ReadByte(); // flag
byte dataType = headerReader.ReadByte();
TapHeaderType headerType = TapHeader.GetTapHeaderTypeFromDataType(dataType);
switch (headerType)
{
case TapHeaderType.ProgramHeader:
tapDataBlock = new ProgramHeader();
break;
case TapHeaderType.NumberArrayHeader:
case TapHeaderType.StringArrayHeader:
tapDataBlock = new AlphanumArrayHeader(dataType);
break;
default:
//case TapHeaderType.ByteArrayHeader:
tapDataBlock = new ByteArrayHeader();
break;
}
TapHeader tapHeader = (TapHeader)tapDataBlock;
tapHeader.FileName = Encoding.GetEncoding("ISO-8859-1").GetString(headerReader.ReadBytes(10));
tapHeader.FollowingDataLength = headerReader.ReadUInt16();
switch (headerType)
{
case TapHeaderType.ProgramHeader:
ReadProgramHeader(headerReader, (ProgramHeader)tapDataBlock);
break;
case TapHeaderType.NumberArrayHeader:
case TapHeaderType.StringArrayHeader:
ReadAlphanumArrayHeader(headerReader, (AlphanumArrayHeader)tapDataBlock);
break;
default:
//case TapHeaderType.ByteArrayHeader:
ReadByteArrayHeader(headerReader, (ByteArrayHeader)tapDataBlock);
break;
}
}
}
// Anonymous data block
else
{
tapDataBlock = new TapDataBlock();
tapDataBlock.Flag = flag;
}
tapDataBlock.DataLength = dataLength;
tapDataBlock.TapeData = tapeData;
if (dataLength >= 2)
{
tapDataBlock.CheckSum = tapeData[dataLength - 1];
tapDataBlock.HasInvalidChecksum = !CheckIfChecksumIsValid(tapDataBlock);
}
}
return(tapDataBlock);
}