/// <summary>
/// Creates a new <see cref="CommandFrame"/> from the given <paramref name="buffer"/>.
/// </summary>
/// <param name="buffer">Binary image to parse.</param>
/// <param name="startIndex">Start index into <paramref name="buffer"/> to begin parsing.</param>
/// <param name="length">Length of valid data within <paramref name="buffer"/>.</param>
/// <remarks>
/// This constructor is used by a consumer to parse a received IEEE C37.118 command frame. Typically
/// command frames are sent to a device. This constructor would used if this code was being used
/// inside of a phasor measurement device.
/// </remarks>
/// <exception cref="ArgumentOutOfRangeException"><paramref name="length"/> is not large enough to parse frame.</exception>
public CommandFrame(byte[] buffer, int startIndex, int length)
: base(new CommandCellCollection(Common.MaximumExtendedDataLength), DeviceCommand.ReservedBits)
{
if (length < CommonFrameHeader.FixedLength)
{
throw new ArgumentOutOfRangeException("length");
}
m_frameHeader = new CommonFrameHeader(null, buffer, startIndex);
if (m_frameHeader.TypeID != IEEEC37_118.FrameType.CommandFrame)
{
throw new InvalidOperationException("Binary image does not represent an IEEE C37.118 command frame");
}
if (length < m_frameHeader.FrameLength)
{
throw new ArgumentOutOfRangeException("length", string.Format("Buffer size, {0}, is not large enough to parse IEEE C37.118 command frame with a length of {1}", length, m_frameHeader.FrameLength));
}
// Validate check-sum
int sumLength = m_frameHeader.FrameLength - 2;
if (BigEndian.ToUInt16(buffer, startIndex + sumLength) != CalculateChecksum(buffer, startIndex, sumLength))
{
throw new InvalidOperationException("Invalid binary image detected - check sum of " + this.GetType().Name + " did not match");
}
m_frameHeader.State = new CommandFrameParsingState(m_frameHeader.FrameLength, m_frameHeader.DataLength, true, true);
CommonHeader = m_frameHeader;
ParseBinaryImage(buffer, startIndex, length);
}
/// <summary>
/// Creates a new <see cref="ConfigurationFrame1"/> from serialization parameters.
/// </summary>
/// <param name="info">The <see cref="SerializationInfo"/> with populated with data.</param>
/// <param name="context">The source <see cref="StreamingContext"/> for this deserialization.</param>
protected ConfigurationFrame1(SerializationInfo info, StreamingContext context)
: base(info, context)
{
// Deserialize configuration frame
m_frameHeader = (CommonFrameHeader)info.GetValue("frameHeader", typeof(CommonFrameHeader));
m_timebase = info.GetUInt32("timebase");
}
/// <summary>
/// Parses the binary image.
/// </summary>
/// <param name="buffer">Binary image to parse.</param>
/// <param name="startIndex">Start index into <paramref name="buffer"/> to begin parsing.</param>
/// <param name="length">Length of valid data within <paramref name="buffer"/>.</param>
/// <returns>The length of the data that was parsed.</returns>
/// <remarks>
/// This method is overridden to parse from cumulated frame images.
/// </remarks>
public override int ParseBinaryImage(byte[] buffer, int startIndex, int length)
{
CommonFrameHeader frameHeader = CommonHeader;
// Handle normal parsing if configuration frame is not fragmented
if (frameHeader is null || frameHeader.ContinuationIndex == 0)
{
return(base.ParseBinaryImage(buffer, startIndex, length));
}
// If all configuration frame images have been received, we can safely start parsing
if (frameHeader.IsLastFrame)
{
using (FrameImageCollector frameImages = frameHeader.FrameImages)
{
if (frameImages is null)
{
return(State.ParsedBinaryLength);
}
buffer = frameImages.BinaryImage;
length = frameImages.BinaryLength;
startIndex = 0;
// Base class will check CRC for entire image
return(base.ParseBinaryImage(buffer, startIndex, length));
}
}
// There are more configuration frame 3 images coming, keep parser moving
// by returning total frame length that was already parsed (or cumulated).
return(State.ParsedBinaryLength);
}
/// <summary>
/// Parses a common header instance that implements <see cref="ICommonHeader{TTypeIdentifier}"/> for the output type represented
/// in the binary image.
/// </summary>
/// <param name="buffer">Buffer containing data to parse.</param>
/// <param name="offset">Offset index into buffer that represents where to start parsing.</param>
/// <param name="length">Maximum length of valid data from offset.</param>
/// <returns>The <see cref="ICommonHeader{TTypeIdentifier}"/> which includes a type ID for the <see cref="Type"/> to be parsed.</returns>
/// <remarks>
/// <para>
/// Derived classes need to provide a common header instance (i.e., class that implements <see cref="ICommonHeader{TTypeIdentifier}"/>)
/// for the output types; this will primarily include an ID of the <see cref="Type"/> that the data image represents. This parsing is
/// only for common header information, actual parsing will be handled by output type via its <see cref="ISupportBinaryImage.ParseBinaryImage"/>
/// method. This header image should also be used to add needed complex state information about the output type being parsed if needed.
/// </para>
/// <para>
/// If there is not enough buffer available to parse common header (as determined by <paramref name="length"/>), return null. Also, if
/// the protocol allows frame length to be determined at the time common header is being parsed and there is not enough buffer to parse
/// the entire frame, it will be optimal to prevent further parsing by returning null.
/// </para>
/// </remarks>
protected override ICommonHeader <FrameType> ParseCommonHeader(byte[] buffer, int offset, int length)
{
// See if there is enough data in the buffer to parse the common frame header.
if (length >= CommonFrameHeader.FixedLength)
{
// Parse common frame header
CommonFrameHeader parsedFrameHeader = new CommonFrameHeader(m_configurationFrame2, buffer, offset);
// Look for probable misaligned bad frame header parse
if (parsedFrameHeader.FrameType == FundamentalFrameType.Undetermined || parsedFrameHeader.Version > 3)
{
throw new InvalidOperationException("Probable frame misalignment detected, forcing scan ahead to next sync byte");
}
// As an optimization, we also make sure entire frame buffer image is available to be parsed - by doing this
// we eliminate the need to validate length on all subsequent data elements that comprise the frame
if (length >= parsedFrameHeader.FrameLength)
{
// Expose the frame buffer image in case client needs this data for any reason
OnReceivedFrameBufferImage(parsedFrameHeader.FrameType, buffer, offset, parsedFrameHeader.FrameLength);
// Handle special parsing states
switch (parsedFrameHeader.TypeID)
{
case FrameType.DataFrame:
// Assign data frame parsing state
parsedFrameHeader.State = new DataFrameParsingState(parsedFrameHeader.FrameLength, m_configurationFrame2, DataCell.CreateNewCell, TrustHeaderLength, ValidateDataFrameCheckSum);
break;
case FrameType.ConfigurationFrame1:
case FrameType.ConfigurationFrame2:
// Assign configuration frame parsing state
parsedFrameHeader.State = new ConfigurationFrameParsingState(parsedFrameHeader.FrameLength, ConfigurationCell.CreateNewCell, TrustHeaderLength, ValidateConfigurationFrameCheckSum);
break;
case FrameType.ConfigurationFrame3:
// parsedFrameHeader.State = new ConfigurationFrameParsingState(parsedFrameHeader.FrameLength, ConfigurationCell3.CreateNewCell, TrustHeaderLength, ValidateConfigurationFrameCheckSum);
break;
case FrameType.HeaderFrame:
// Assign header frame parsing state
parsedFrameHeader.State = new HeaderFrameParsingState(parsedFrameHeader.FrameLength, parsedFrameHeader.DataLength, TrustHeaderLength, ValidateHeaderFrameCheckSum);
break;
}
return(parsedFrameHeader);
}
}
return(null);
}
/// <summary>
/// Creates a new <see cref="CommandFrame"/> from serialization parameters.
/// </summary>
/// <param name="info">The <see cref="SerializationInfo"/> with populated with data.</param>
/// <param name="context">The source <see cref="StreamingContext"/> for this deserialization.</param>
protected CommandFrame(SerializationInfo info, StreamingContext context)
: base(info, context)
{
// Deserialize command frame
m_frameHeader = (CommonFrameHeader)info.GetValue("frameHeader", typeof(CommonFrameHeader));
}