/// <summary>
/// Reads field definitions.
/// </summary>
protected FieldDef[] ReadFieldDefs(BinaryReader reader, byte[] buffer, int fieldCount)
{
FieldDef[] fieldDefs = new FieldDef[fieldCount];
for (int i = 0; i < fieldCount; i++)
{
ReadData(reader, buffer, 0, FieldDefSize, true);
if (ScadaUtils.CRC16(buffer, 0, FieldDefSize - 2) != BitConverter.ToUInt16(buffer, FieldDefSize - 2))
{
throw new ScadaException("Field definition CRC error.");
}
int index = 0;
int nameLength = buffer[index++];
string fieldName = Encoding.ASCII.GetString(buffer, index, nameLength);
index += MaxFieldNameLength;
fieldDefs[i] = new FieldDef(
fieldName,
GetByte(buffer, ref index),
GetBool(buffer, ref index));
}
return(fieldDefs);
}
/// <summary>
/// Copies the event to the buffer.
/// </summary>
protected void CopyEvent(Event ev, bool textExists, bool dataExists,
byte[] buffer, out int textSize, out int dataSize)
{
textSize = ev.Text == null ? 0 : Math.Min(ev.Text.Length, MaxTextSize);
dataSize = ev.Data == null ? 0 : Math.Min(ev.Data.Length, MaxDataSize);
int index = 0;
CopyUInt16(BlockMarker, buffer, ref index);
CopyInt64(ev.EventID, buffer, ref index);
CopyTime(ev.Timestamp, buffer, ref index);
CopyBool(ev.Hidden, buffer, ref index);
CopyInt32(ev.CnlNum, buffer, ref index);
CopyInt32(ev.OutCnlNum, buffer, ref index);
CopyInt32(ev.ObjNum, buffer, ref index);
CopyInt32(ev.DeviceNum, buffer, ref index);
CopyDouble(ev.PrevCnlVal, buffer, ref index);
CopyUInt16((ushort)ev.PrevCnlStat, buffer, ref index);
CopyDouble(ev.CnlVal, buffer, ref index);
CopyUInt16((ushort)ev.CnlStat, buffer, ref index);
CopyInt32(ev.Severity, buffer, ref index);
CopyBool(ev.AckRequired, buffer, ref index);
CopyBool(ev.Ack, buffer, ref index);
CopyTime(ev.AckTimestamp, buffer, ref index);
CopyInt32(ev.AckUserID, buffer, ref index);
CopyByte((byte)ev.TextFormat, buffer, ref index);
CopyBool(textExists, buffer, ref index);
CopyByte((byte)textSize, buffer, ref index);
CopyBool(dataExists, buffer, ref index);
CopyByte((byte)dataSize, buffer, ref index);
Array.Clear(buffer, index, EventSize - index - 2);
ushort crc = ScadaUtils.CRC16(buffer, 0, EventSize - 2);
CopyUInt16(crc, buffer, EventSize - 2);
}
/// <summary>
/// Writes the field definintion using the specified writer.
/// </summary>
protected void WriteFieldDef(BinaryWriter writer, FieldDef fieldDef, byte[] buffer)
{
Array.Clear(buffer, 0, FieldDefSize);
int nameLength = fieldDef.Name.Length;
buffer[0] = (byte)nameLength;
Encoding.ASCII.GetBytes(fieldDef.Name).CopyTo(buffer, 1);
buffer[MaxFieldNameLength + 1] = (byte)fieldDef.DataType;
buffer[MaxFieldNameLength + 2] = (byte)(fieldDef.AllowNull ? 1 : 0);
ushort crc = ScadaUtils.CRC16(buffer, 0, FieldDefSize - 2);
CopyUInt16(crc, buffer, FieldDefSize - 2);
writer.Write(buffer, 0, FieldDefSize);
}
/// <summary>
/// Writes the event acknowledgement information in a file or stream.
/// </summary>
public void WriteEventAck(Event ev)
{
if (ev == null)
{
throw new ArgumentNullException(nameof(ev));
}
if (ev.Position < 0)
{
throw new ScadaException("Event position is undefined.");
}
Stream stream = null;
BinaryReader reader = null;
BinaryWriter writer = null;
try
{
stream = Stream ?? new FileStream(FileName, FileMode.OpenOrCreate, FileAccess.ReadWrite, FileShare.ReadWrite);
reader = new BinaryReader(stream, Encoding.UTF8, Stream != null);
writer = new BinaryWriter(stream, Encoding.UTF8, Stream != null);
// read the existing event into the buffer
byte[] buffer = new byte[EventSize];
if (stream.Seek(ev.Position, SeekOrigin.Begin) == ev.Position &&
ReadEvent(reader, buffer, out int index) &&
GetInt64(buffer, ref index) == ev.EventID)
{
// update the event in the buffer
index = 58;
CopyBool(ev.Ack, buffer, ref index);
CopyTime(ev.AckTimestamp, buffer, ref index);
CopyInt32(ev.AckUserID, buffer, ref index);
ushort crc = ScadaUtils.CRC16(buffer, 0, EventSize - 2);
CopyUInt16(crc, buffer, EventSize - 2);
// write the updated buffer
stream.Seek(ev.Position, SeekOrigin.Begin);
writer.Write(buffer);
}
}
finally
{
reader?.Close();
writer?.Close();
}
}
/// <summary>
/// Reads a row to the buffer.
/// </summary>
protected void ReadRowToBuffer(BinaryReader reader, ref byte[] buffer)
{
if (reader.ReadUInt16() != BlockMarker)
{
throw new ScadaException("Row marker not found.");
}
int rowDataSize = reader.ReadInt32();
int fullRowSize = rowDataSize + 6;
ResizeBuffer(ref buffer, fullRowSize, 2);
ReadData(reader, buffer, 6, rowDataSize, true);
// copy values to the buffer to calculate CRC
CopyUInt16(BlockMarker, buffer, 0);
CopyInt32(rowDataSize, buffer, 2);
if (ScadaUtils.CRC16(buffer, 0, fullRowSize - 2) != BitConverter.ToUInt16(buffer, fullRowSize - 2))
{
throw new ScadaException("Row CRC error.");
}
}
/// <summary>
/// Reads an event into the buffer and validates the event.
/// </summary>
protected bool ReadEvent(BinaryReader reader, byte[] buffer, out int index)
{
index = 0;
if (reader.Read(buffer, 0, EventSize) == EventSize)
{
if (GetUInt16(buffer, ref index) != BlockMarker)
{
throw new ScadaException("Event marker not found.");
}
if (ScadaUtils.CRC16(buffer, 0, EventSize - 2) != BitConverter.ToUInt16(buffer, EventSize - 2))
{
throw new ScadaException("Event CRC error.");
}
return(true);
}
else
{
return(false);
}
}
/// <summary>
/// Updates the configuration database by writing data of the specified table.
/// </summary>
public void Update(IBaseTable baseTable)
{
if (baseTable == null)
{
throw new ArgumentNullException(nameof(baseTable));
}
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.BaseTable);
writer.Write(MajorVersion);
writer.Write(MinorVersion);
PropertyDescriptorCollection props = TypeDescriptor.GetProperties(baseTable.ItemType);
int fieldCount = Math.Min(props.Count, ushort.MaxValue);
writer.Write((ushort)fieldCount);
writer.Write(ReserveBuffer, 0, 12);
if (fieldCount > 0)
{
// create and write field definitions
FieldDef[] fieldDefs = new FieldDef[fieldCount];
byte[] buffer = new byte[FieldDefSize];
for (int i = 0; i < fieldCount; i++)
{
PropertyDescriptor prop = props[i];
bool isNullable = prop.PropertyType.IsNullable();
FieldDef fieldDef = new FieldDef(
prop.Name,
isNullable ? Nullable.GetUnderlyingType(prop.PropertyType) : prop.PropertyType,
isNullable || prop.PropertyType.IsClass);
fieldDefs[i] = fieldDef;
WriteFieldDef(writer, fieldDef, buffer);
}
// write rows
byte[][] rowData = new byte[fieldCount][];
bool[] isNullArr = new bool[fieldCount];
foreach (object item in baseTable.EnumerateItems())
{
// get row data and size
int rowDataSize = 2; // CRC
for (int i = 0; i < fieldCount; i++)
{
object value = props[i].GetValue(item);
if (value == null)
{
isNullArr[i] = true;
}
else
{
FieldDef fieldDef = fieldDefs[i];
byte[] fieldData = GetFieldData(fieldDef, value, rowData[i]);
rowData[i] = fieldData;
isNullArr[i] = false;
rowDataSize += (fieldDef.DataSize <= 0 ? 2 : 0) + fieldData.Length;
}
rowDataSize++; // null flag
}
// copy row data to the buffer
int fullRowSize = rowDataSize + 6;
int copyIndex = 0;
ResizeBuffer(ref buffer, fullRowSize, 2);
CopyUInt16(BlockMarker, buffer, ref copyIndex);
CopyInt32(rowDataSize, buffer, ref copyIndex);
for (int i = 0; i < fieldCount; i++)
{
if (isNullArr[i])
{
buffer[copyIndex++] = 1;
}
else
{
buffer[copyIndex++] = 0;
FieldDef fieldDef = fieldDefs[i];
byte[] fieldData = rowData[i];
if (fieldDef.DataSize <= 0)
{
CopyUInt16((ushort)fieldData.Length, buffer, ref copyIndex);
}
fieldData.CopyTo(buffer, copyIndex);
copyIndex += fieldData.Length;
}
}
ushort crc = ScadaUtils.CRC16(buffer, 0, fullRowSize - 2);
CopyUInt16(crc, buffer, fullRowSize - 2);
// write row data
writer.Write(buffer, 0, fullRowSize);
}
}
}
finally
{
writer?.Close();
}
}
