/// <summary>
/// Retrieve a value from the cluster dictionary. Being that this could invoke a call to another machine over the network,
/// the retrieval must be asynchronous and invoke a callback upon completion. If retrieval does not need to go across the network,
/// the callback is immediately run.
/// </summary>
/// <param name="key">The Key of the value to retrieve.</param>
/// <param name="callback">The callback to be run after the value is retrieved.</param>
/// <param name="state">A state to carry with the async call and passed into the callback.</param>
public ClusterDictionaryResult <T> Get(string key, Action <ClusterDictionaryResult <T> > callback, Object state)
{
ClusterDictionaryResult <T> result = new ClusterDictionaryResult <T>();
result.AsyncState = state;
result.IsCompleted = false;
result.ResultErrorState = AsyncResultErrorState.NONE;
getter.BeginInvoke(key, callback, result, null, null);
return(result);
}
//----------------------The get and set functions----------------------//
//This is kind of weird, I admit, but I had to think of an efficient way to manage this. Each different policy added gives
//an exponential increase in the number of code paths, so what we do is just split it all up into different compact possibilities.
//This way, there is only one code path, and that code path is simply created during initialization of the instance.
private void getLocal(string key, Action <ClusterDictionaryResult <T> > callback, ClusterDictionaryResult <T> result)
{
if (map.ContainsKey(key))
{
//The internal map has the value and we can get local, get it immediately and return
T value = map[key].GetValue();
result.Value = value;
result.LocallyObtained = true;
result.IsCompleted = true;
result.ResultErrorState = AsyncResultErrorState.NONE;
if (callback != null)
{
callback.BeginInvoke(result, null, null);
}
}
else
{
//create a callback id and issue a cross network request for data
}
}