/// <summary>
/// Parses source definitions for an annotation query.
/// </summary>
/// <param name="annotation">Grafana annotation.</param>
/// <param name="type">Annotation type.</param>
/// <param name="source">Metadata of source definitions.</param>
/// <param name="useFilterExpression">Determines if query is using a filter expression.</param>
/// <returns>Parsed source definitions from <paramref name="annotation"/>.</returns>
public static Dictionary <string, DataRow> ParseSourceDefinitions(this Annotation annotation, AnnotationType type, DataSet source, bool useFilterExpression)
{
if ((object)annotation == null)
{
throw new ArgumentNullException(nameof(annotation));
}
if ((object)source == null)
{
throw new ArgumentNullException(nameof(source));
}
if (type == AnnotationType.Undefined)
{
throw new InvalidOperationException("Unrecognized type or syntax for annotation query expression.");
}
string query = annotation.query ?? "";
return(TargetCache <Dictionary <string, DataRow> > .GetOrAdd(query, () =>
{
DataRow[] rows;
if (useFilterExpression)
{
string tableName, expression, sortField;
int takeCount;
if (AdapterBase.ParseFilterExpression(query, out tableName, out expression, out sortField, out takeCount))
{
rows = source.Tables[tableName.Translate()].Select(expression, sortField).Take(takeCount).ToArray();
}
else
{
throw new InvalidOperationException("Invalid FILTER syntax for annotation query expression.");
}
}
else
{
// Assume all records if no filter expression was provided
rows = source.Tables[type.TableName().Translate()].Rows.Cast <DataRow>().ToArray();
}
Dictionary <string, DataRow> definitions = new Dictionary <string, DataRow>(StringComparer.OrdinalIgnoreCase);
foreach (DataRow row in rows)
{
MeasurementKey key = GetTargetFromGuid(row[type.TargetFieldName()].ToString());
if (key != MeasurementKey.Undefined)
{
definitions[key.TagFromKey(source)] = row;
}
}
return definitions;
}));
}
