/// <summary>
/// Calculates the CRC of the channel numbers.
/// </summary>
protected uint CalculateCRC()
{
int dataLength = CnlNums.Length * 4;
byte[] buffer = new byte[dataLength];
Buffer.BlockCopy(CnlNums, 0, buffer, 0, dataLength);
return(ScadaUtils.CRC32(buffer, 0, dataLength));
}
/// <summary>
/// Writes the single slice to a file or stream.
/// </summary>
public void WriteSingleSlice(Slice slice)
{
if (slice == null)
{
throw new ArgumentNullException(nameof(slice));
}
Stream stream;
BinaryWriter writer = null;
try
{
stream = Stream ?? new FileStream(FileName, FileMode.Create, FileAccess.Write, FileShare.ReadWrite);
writer = new BinaryWriter(stream, Encoding.UTF8, Stream != null);
// write header
writer.Write(TableType.SliceTable);
writer.Write(MajorVersion);
writer.Write(MinorVersion);
writer.Write(ReserveBuffer, 0, 14);
// write slice
int cnlCnt = slice.CnlNums.Length;
int sliceSize = cnlCnt > 0 ? cnlCnt * 14 + 18 : 14;
ResizeBuffer(ref sliceBuffer, sliceSize);
byte[] buffer = sliceBuffer;
int index = 0;
CopyUInt16(BlockMarker, buffer, ref index);
CopyTime(slice.Timestamp, buffer, ref index);
CopyInt32(cnlCnt, buffer, ref index);
if (cnlCnt > 0)
{
int dataLength = cnlCnt * 4;
Buffer.BlockCopy(slice.CnlNums, 0, buffer, index, dataLength);
uint crc = ScadaUtils.CRC32(buffer, index, dataLength);
index += dataLength;
CopyInt32((int)crc, buffer, ref index);
foreach (CnlData cnlData in slice.CnlData)
{
CopyCnlData(cnlData, buffer, ref index);
}
}
writer.Write(buffer, 0, index);
}
finally
{
writer?.Close();
}
}
/// <summary>
/// Fills the specified table by reading data from a file or stream.
/// </summary>
public void Fill(DataTable dataTable)
{
if (dataTable == null)
{
throw new ArgumentNullException(nameof(dataTable));
}
Stream stream;
BinaryReader reader = null;
try
{
stream = Stream ?? new FileStream(FileName, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
reader = new BinaryReader(stream, Encoding.UTF8, Stream != null);
// prepare the data table
dataTable.Rows.Clear();
dataTable.BeginLoadData();
dataTable.DefaultView.Sort = "";
// create table columns
if (dataTable.Columns.Count == 0)
{
dataTable.Columns.Add("DateTime", typeof(DateTime));
dataTable.Columns.Add("CnlNum", typeof(int));
dataTable.Columns.Add("Val", typeof(double));
dataTable.Columns.Add("Stat", typeof(int));
}
// read header
byte[] buffer = new byte[HeaderSize];
if (!ReadHeader(reader, buffer))
{
return;
}
// read slices
int[] cnlNums = null;
while (true)
{
if (reader.ReadUInt16() != BlockMarker)
{
throw new ScadaException("Slice marker not found.");
}
DateTime timestamp = ScadaUtils.TicksToTime(reader.ReadInt64());
int cnlCnt = reader.ReadInt32();
if (cnlCnt != 0)
{
int cnlDataSize = cnlCnt * 10;
int cnlNumsSize = cnlCnt * 4;
ResizeBuffer(ref buffer, cnlDataSize);
// read channel numbers
if (cnlCnt > 0)
{
ReadData(reader, buffer, 0, cnlNumsSize + 4, true);
cnlNums = new int[cnlCnt];
Buffer.BlockCopy(buffer, 0, cnlNums, 0, cnlNumsSize);
if (ScadaUtils.CRC32(buffer, 0, cnlNumsSize) != BitConverter.ToUInt32(buffer, cnlNumsSize))
{
throw new ScadaException("CRC error.");
}
}
else if (cnlCnt < 0) // channel numbers are the same
{
cnlCnt = ~cnlCnt;
if (cnlNums == null)
{
throw new ScadaException("Channel numbers are undefined.");
}
if (cnlNums.Length != cnlCnt)
{
throw new ScadaException("Invalid channel count.");
}
}
// read channel data
ReadData(reader, buffer, 0, cnlDataSize, true);
for (int i = 0, index = 0; i < cnlCnt; i++)
{
DataRow row = dataTable.NewRow();
row["DateTime"] = timestamp;
row["CnlNum"] = cnlNums[i];
row["Val"] = GetDouble(buffer, ref index);
row["Stat"] = GetUInt16(buffer, ref index);
dataTable.Rows.Add(row);
}
}
}
}
catch (EndOfStreamException)
{
// normal file ending case
}
finally
{
reader?.Close();
dataTable.EndLoadData();
dataTable.AcceptChanges();
if (dataTable.Columns.Count > 0)
{
dataTable.DefaultView.Sort = "DateTime, CnlNum";
}
}
}
/// <summary>
/// Reads a single slice from a file or stream.
/// </summary>
public Slice ReadSingleSlice()
{
Stream stream;
BinaryReader reader = null;
try
{
stream = Stream ?? new FileStream(FileName, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
reader = new BinaryReader(stream, Encoding.UTF8, Stream != null);
// read header
byte[] buffer = new byte[HeaderSize];
if (!ReadHeader(reader, buffer))
{
return(null);
}
// read the first slice
if (reader.ReadUInt16() != BlockMarker)
{
throw new ScadaException("Slice marker not found.");
}
DateTime timestamp = ScadaUtils.TicksToTime(reader.ReadInt64());
int cnlCnt = reader.ReadInt32();
if (cnlCnt > 0)
{
// read channel numbers
int cnlDataSize = cnlCnt * 10;
int cnlNumsSize = cnlCnt * 4;
buffer = new byte[cnlDataSize];
ReadData(reader, buffer, 0, cnlNumsSize + 4, true);
int[] cnlNums = new int[cnlCnt];
Buffer.BlockCopy(buffer, 0, cnlNums, 0, cnlNumsSize);
if (ScadaUtils.CRC32(buffer, 0, cnlNumsSize) != BitConverter.ToUInt32(buffer, cnlNumsSize))
{
throw new ScadaException("CRC error.");
}
// read channel data
ReadData(reader, buffer, 0, cnlDataSize, true);
CnlData[] cnlData = new CnlData[cnlCnt];
for (int i = 0, index = 0; i < cnlCnt; i++)
{
cnlData[i] = GetCnlData(buffer, ref index);
}
return(new Slice(timestamp, cnlNums, cnlData));
}
else if (cnlCnt == 0)
{
return(new Slice(timestamp, 0));
}
else
{
throw new ScadaException("Invalid channel count.");
}
}
catch (EndOfStreamException)
{
// unable to read slice
return(null);
}
finally
{
reader?.Close();
}
}
