/// <summary>
/// Checks if the reference fields in a given message indicate the subfield (alternate)
/// definition should be used
/// </summary>
/// <param name="mesg">message of interest</param>
/// <returns>true if the subfield is active</returns>
internal bool CanMessageSupport(Message mesg)
{
Field field = mesg.GetField(refFieldNum);
if (field != null)
{
object value = field.GetValue(0, Fit.SubfieldIndexMainField);
// Float refvalues are not supported
if (Convert.ToInt64(value) == Convert.ToInt64(refFieldValue))
{
return(true);
}
}
return(false);
}
public void DecodeNextMessage(Stream fitStream)
{
BinaryReader br = new BinaryReader(fitStream);
byte nextByte = br.ReadByte();
// Is it a compressed timestamp mesg?
if ((nextByte & Fit.CompressedHeaderMask) == Fit.CompressedHeaderMask)
{
MemoryStream mesgBuffer = new MemoryStream();
int timeOffset = nextByte & Fit.CompressedTimeMask;
timestamp += (uint)((timeOffset - lastTimeOffset) & Fit.CompressedTimeMask);
lastTimeOffset = timeOffset;
Field timestampField = new Field(Profile.GetMessage(MessageNum.Record).GetField("Timestamp"));
timestampField.SetValue(timestamp);
byte localMessageNum = (byte)((nextByte & Fit.CompressedLocalMessageNumMask) >> 5);
mesgBuffer.WriteByte(localMessageNum);
if (localMessageDefs[localMessageNum] == null)
{
throw new FitException("Decode:DecodeNextMessage - FIT decode error: Missing message definition for local message number " + localMessageNum + " at stream position " + fitStream.Position);
}
int fieldsSize = localMessageDefs[localMessageNum].GetMessageSize() - 1;
try
{
byte[] read = br.ReadBytes(fieldsSize);
if (read.Length < fieldsSize)
{
throw new Exception("Field size mismatch, expected: " + fieldsSize + "received: " + read.Length);
}
mesgBuffer.Write(read, 0, fieldsSize);
}
catch (Exception e)
{
throw new FitException("Decode:DecodeNextMessage - Compressed Data Message unexpected end of file. Wanted " + fieldsSize + " bytes at stream position " + fitStream.Position, e);
}
Message newMessage = new Message(mesgBuffer, localMessageDefs[localMessageNum]);
newMessage.InsertField(0, timestampField);
RaiseMessageEvent(newMessage);
}
// Is it a mesg def?
else if ((nextByte & Fit.MessageDefinitionMask) == Fit.MessageDefinitionMask)
{
MemoryStream mesgDefBuffer = new MemoryStream();
// Figure out number of fields (length) of our defn and build buffer
mesgDefBuffer.WriteByte(nextByte);
mesgDefBuffer.Write(br.ReadBytes(4), 0, 4);
byte numFields = br.ReadByte();
mesgDefBuffer.WriteByte(numFields);
int numBytes = numFields * 3; //3 Bytes per field
try
{
byte[] read = br.ReadBytes(numBytes);
if (read.Length < numBytes)
{
throw new Exception("Message Definition size mismatch, expected: " + numBytes + "received: " + read.Length);
}
mesgDefBuffer.Write(read, 0, numBytes);
if ((nextByte & Fit.DevDataMask) == Fit.DevDataMask)
{
// Definition Contains Dev Data
byte numDevFields = br.ReadByte();
mesgDefBuffer.WriteByte(numDevFields);
numBytes = numDevFields * 3;
read = br.ReadBytes(numBytes);
if (read.Length < numBytes)
{
throw new Exception("Message Definition size mismatch, expected: " + numBytes + "received: " + read.Length);
}
// Read Dev Data
mesgDefBuffer.Write(read, 0, numBytes);
}
}
catch (Exception e)
{
throw new FitException("Decode:DecodeNextMessage - Defn Message unexpected end of file. Wanted " + numBytes + " bytes at stream position " + fitStream.Position, e);
}
MessageDefinition newMessageDef = new MessageDefinition(mesgDefBuffer, m_lookup);
localMessageDefs[newMessageDef.LocalMessageNum] = newMessageDef;
if (MessageDefinitionEvent != null)
{
MessageDefinitionEvent(this, new MessageDefinitionEventArgs(newMessageDef));
}
}
// Is it a data mesg?
else if ((nextByte & Fit.MessageDefinitionMask) == Fit.MessageHeaderMask)
{
MemoryStream mesgBuffer = new MemoryStream();
byte localMessageNum = (byte)(nextByte & Fit.LocalMessageNumMask);
mesgBuffer.WriteByte(localMessageNum);
if (localMessageDefs[localMessageNum] == null)
{
throw new FitException("Decode:DecodeNextMessage - FIT decode error: Missing message definition for local message number " + localMessageNum + " at stream position " + fitStream.Position);
}
int fieldsSize = localMessageDefs[localMessageNum].GetMessageSize() - 1;
try
{
byte[] read = br.ReadBytes(fieldsSize);
if (read.Length < fieldsSize)
{
throw new Exception("Field size mismatch, expected: " + fieldsSize + "received: " + read.Length);
}
mesgBuffer.Write(read, 0, fieldsSize);
}
catch (Exception e)
{
throw new FitException("Decode:DecodeNextMessage - Data Message unexpected end of file. Wanted " + fieldsSize + " bytes at stream position " + fitStream.Position, e);
}
Message newMessage = new Message(mesgBuffer, localMessageDefs[localMessageNum]);
// If the new message contains a timestamp field, record the value to use as
// a reference for compressed timestamp headers
Field timestampField = newMessage.GetField("Timestamp");
if (timestampField != null)
{
object tsValue = timestampField.GetValue();
if (tsValue != null)
{
timestamp = (uint)tsValue;
lastTimeOffset = (int)timestamp & Fit.CompressedTimeMask;
}
}
foreach (Field field in newMessage.FieldsList)
{
if (field.IsAccumulated)
{
int i;
for (i = 0; i < field.GetNumValues(); i++)
{
long value = Convert.ToInt64(field.GetRawValue(i));
foreach (Field fieldIn in newMessage.FieldsList)
{
foreach (FieldComponent fc in fieldIn.components)
{
if ((fc.fieldNum == field.Num) && (fc.accumulate))
{
value = (long)((((value / field.Scale) - field.Offset) + fc.offset) * fc.scale);
}
}
}
accumulator.Set(newMessage.MessageNumber, field.Num, value);
}
}
}
// Now that the entire message is decoded we can evaluate subfields and expand any components
newMessage.ExpandComponents(accumulator);
RaiseMessageEvent(newMessage);
}
else
{
throw new FitException("Decode:Read - FIT decode error: Unexpected Object Header Byte 0x" + nextByte.ToString("X") + " at stream position: " + fitStream.Position);
}
}
