/// <summary>
/// Stores supplemental metadata representing distinct dictionary keys seen on the stream.
/// </summary>
/// <typeparam name="TKey">The type of dictionary key in the stream.</typeparam>
/// <typeparam name="TValue">The type of dictionary value in the stream.</typeparam>
/// <param name="source">The source stream to write.</param>
public void SummarizeDistinctKeysInSupplementalMetadata <TKey, TValue>(Emitter <Dictionary <TKey, TValue> > source)
{
if (!this.writer.TryGetMetadata(source.Id, out PsiStreamMetadata meta))
{
throw new ArgumentException("Stream metadata is not available because the stream has not been written.");
}
// update supplemental meta to reflect distinct keys seen
source.Aggregate(
new SortedSet <TKey>(),
(set, dict) =>
{
foreach (var key in dict.Keys)
{
if (!set.Contains(key))
{
set.UnionWith(dict.Keys);
meta.SetSupplementalMetadata(new DistinctKeysSupplementalMetadata <TKey>(set), this.serializers);
return(set);
}
}
return(set);
},
DeliveryPolicy.Unlimited);
}