public Task AddItem(KeyValuePosition grain)
{
if (this.State.Members.ContainsKey(grain.Key))
{
this.State.Members[grain.Key] = grain;
}
else
{
this.State.Members.Add(grain.Key, grain);
}
return(this.WriteStateAsync());
}
public async Task <string> SetValueAndPosition(string value, Position newPosition, string eTag)
{
if (null != eTag && eTag != this.State.Etag)
{
throw new ArgumentException("eTag");
}
if (this.State.CurrentPosition == newPosition)
{
return(this.State.Etag);
}
var oldPosition = this.State.CurrentPosition;
this.State.CurrentPosition = newPosition;
this.State.Value = value;
await this.WriteStateAsync();
// think about what to do when failure happens here.
// is there a way to wrap these calls in a transaction?
var kvp = new KeyValuePosition
{
ETag = this.State.Etag,
Key = key,
Position = this.State.CurrentPosition,
Value = this.State.Value
};
var promises = new List <Task>();
foreach (var item in oldPosition.GetDelta(newPosition))
{
var grain = GrainFactory.GetGrain <IQuadKeyGrain>(item.QuadKey);
switch (item.Delta)
{
case ExtensionMethods.Delta.Join:
promises.Add(grain.AddItem(kvp));
break;
case ExtensionMethods.Delta.Leave:
promises.Add(grain.RemoveItem(key));
break;
}
}
await Task.WhenAll(promises);
return(this.State.Etag);
}
