/// <summary>
/// Enumerates the messages in the underlying stream.
/// </summary>
/// <returns>The messages in the GRIB 2 stream.</returns>
public IEnumerable <Message> ReadMessages()
{
reader.Seek(0, SeekOrigin.Begin);
do
{
var indicatorSection = IndicatorSection.BuildFrom(reader);
var identificationSection = IdentificationSection.BuildFrom(reader);
var message = new Message(indicatorSection, identificationSection);
LocalUseSection localUseSection = null;
do
{
if (reader.PeekSection().Is(SectionCode.LocalUseSection))
{
localUseSection = LocalUseSection.BuildFrom(reader);
}
while (reader.PeekSection().Is(SectionCode.GridDefinitionSection))
{
var gridDefinitionSection = GridDefinitionSection.BuildFrom(reader);
while (reader.PeekSection().Is(SectionCode.ProductDefinitionSection))
{
var productDefinitionSection = ProductDefinitionSection.BuildFrom(reader, indicatorSection.Discipline);
var dataRepresentationSection = DataRepresentationSection.BuildFrom(reader);
var bitmapSection = BitmapSection.BuildFrom(reader, dataRepresentationSection.DataPointsNumber);
var dataSection = DataSection.BuildFrom(reader);
message.AddDataset(
localUseSection,
gridDefinitionSection,
productDefinitionSection,
dataRepresentationSection,
bitmapSection,
dataSection);
}
}
} while (!reader.PeekSection().Is(SectionCode.EndSection));
EndSection.BuildFrom(reader);
// Saves and restore the current position
// to avoid losing track of the current message
// if a data set read happens during the enumeration
var currentPosition = reader.Position;
yield return(message);
reader.Seek(currentPosition, SeekOrigin.Begin);
} while (!reader.HasReachedStreamEnd && reader.PeekSection().Is(SectionCode.IndicatorSection));
}
public void BuildFrom_ValidGribFile_Test()
{
using var gribFileStream = File.OpenRead(GribFileSamples.ValidFile);
var reader = new BufferedBinaryReader(gribFileStream);
reader.Seek(16, SeekOrigin.Begin);
var section = IdentificationSection.BuildFrom(reader);
Check.That(section).IsNotNull();
Check.That(section.Length).Equals(21);
Check.That(section.Section).Equals(1);
Check.That(section.CenterCode).Equals(7);
Check.That(section.SubCenterCode).Equals(0);
Check.That(section.MasterTableVersion).Equals(2);
Check.That(section.LocalTableVersion).Equals(1);
Check.That(section.ProductStatus).Equals(ProductStatus.OperationalProducts);
Check.That(section.ProductType).Equals(ProductType.AnalysisProducts);
Check.That(section.ReferenceTimeSignificance).Equals(ReferenceTimeSignificance.Analysis);
Check.That(section.ReferenceTime).Equals(new DateTime(2020, 3, 14, 0, 0, 0, 0, DateTimeKind.Utc));
}