/// <summary>
/// Does not work with BinaryFormatter.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="comm"></param>
/// <param name="inputArray"></param>
/// <param name="indicesToSend"></param>
/// <param name="outputArray"></param>
/// <param name="indicesToReceive"></param>
public static void AlltoallSubarrays2 <T>(ICommunicator comm, IReadOnlyList <T> inputArray, ICollection <int>[] indicesToSend, IList <T> outputArray, ICollection <int>[] indicesToReceive)
{
var sendCounts = indicesToSend.Select(indices => indices.Count).ToArray();
var subarrays = Util.ArrayInit(indicesToSend.Length, recipient => (ICollection <T>) new Subarray <T>(inputArray, indicesToSend[recipient]));
var sendTotalCount = sendCounts.Sum();
var recvCounts = indicesToReceive.Select(indices => indices.Count).ToArray();
var recvTotalCount = recvCounts.Sum();
AlltoallSubarraysItemsTransmitted += sendTotalCount + recvTotalCount;
ICollection <T>[] subarraysReceived = comm.Alltoall(subarrays);
for (int source = 0; source < comm.Size; source++)
{
var indicesOfSubarray = indicesToReceive[source];
if (indicesOfSubarray.Count == 0)
{
continue;
}
var iter = subarraysReceived[source].GetEnumerator();
foreach (int index in indicesOfSubarray)
{
if (!iter.MoveNext())
{
throw new Exception();
}
outputArray[index] = iter.Current;
//Trace.WriteLine($"process {comm.Rank} from {source} received {outputArray[index]} for local index {index} recvPosition = {recvPosition}");
}
}
}
