// Static Constructor
static MeasurementKey()
{
// Order of operations is critical here since MeasurementKey and MeasurementMetadata have a circular reference
Undefined = CreateUndefinedMeasurementKey();
MeasurementMetadata.CreateUndefinedMeasurementMetadata();
Undefined.m_metadata = MeasurementMetadata.Undefined;
}
private MeasurementKey(Guid signalID, ulong id, string source)
{
m_signalID = signalID;
m_id = id;
m_source = source;
m_hashCode = base.GetHashCode();
m_runtimeID = Interlocked.Increment(ref s_nextRuntimeID) - 1; // Returns the incremented value. Hints the -1
m_metadata = new MeasurementMetadata(this, null, 0, 1);
}
/// <summary>
/// Updates the values of the <see cref="Metadata"/>.
/// </summary>
/// <param name="tagName">Gets or sets the text based tag name.</param>
/// <param name="adder">Defines an offset to add to the <see cref="IMeasurement"/> value.</param>
/// <param name="multiplier">Defines a multiplicative offset to apply to the <see cref="IMeasurement"/> value.</param>
public void SetMeasurementMetadata(string tagName, double adder, double multiplier)
{
if (this == Undefined)
{
throw new NotSupportedException("Cannot set data source information for an undefined measurement.");
}
if (m_metadata.TagName != tagName || m_metadata.Adder != adder || m_metadata.Multiplier != multiplier)
{
m_metadata = new MeasurementMetadata(this, tagName, adder, multiplier);
}
}
/// <summary>
/// Constructs a new <see cref="Measurement"/> using default settings.
/// </summary>
public Measurement()
{
m_metadata = MeasurementMetadata.Undefined;
m_lifespan = ShortTime.Now;
}
// Static Methods
// Create measurement metadata for undefined
internal static void CreateUndefinedMeasurementMetadata()
{
s_undefined = s_undefined ?? new MeasurementMetadata(MeasurementKey.Undefined, null, 0, 1);
}