public long GetAndSubtract(long delta)
{
var targetAddress = GetCRDTOperationTarget(_emptyAddressList);
var response = InvokeAddInternal(-delta, true, _emptyAddressList, null, targetAddress);
var decodedResponse = PNCounterAddCodec.DecodeResponse(response);
UpdateObservedReplicaTimestamps(decodedResponse.replicaTimestamps);
return(decodedResponse.value);
}
public long IncrementAndGet()
{
var targetAddress = GetCRDTOperationTarget(_emptyAddressList);
var response = InvokeAddInternal(1, false, _emptyAddressList, null, targetAddress);
var decodedResponse = PNCounterAddCodec.DecodeResponse(response);
UpdateObservedReplicaTimestamps(decodedResponse.replicaTimestamps);
return(decodedResponse.value);
}
/// <summary>
/// Adds the delta and returns the value of the counter before the update
/// if getBeforeUpdate" is true or the value after the update if it is false.
/// It will invoke client messages recursively on viable replica addresses
/// until successful or the list of viable replicas is exhausted.
/// Replicas with addresses contained in the excludedAddresses are skipped.
/// If there are no viable replicas, this method will throw the lastException if not null
/// or a NoDataMemberInClusterException if the lastException is null.
/// </summary>
/// <param name="delta">the delta to add to the counter value, can be negative</param>
/// <param name="getBeforeUpdate">true if the operation should return the counter value before the addition,
/// false if it should return the value after the addition</param>
/// <param name="excludedAddresses">the addresses to exclude when choosing a replica address, must not be null</param>
/// <param name="lastException">the exception thrown from the last invocation of the request on a replica, may be null</param>
/// <param name="targetAddress">the target address</param>
/// <returns>the result of the request invocation on a replica</returns>
/// <exception cref="NoDataMemberInClusterException">if there are no replicas and the lastException is null</exception>
internal IClientMessage InvokeAddInternal(long delta, bool getBeforeUpdate, HashSet <Address> excludedAddresses, Exception lastException, Address targetAddress)
{
if (targetAddress == null)
{
if (lastException != null)
{
throw lastException;
}
throw new NoDataMemberInClusterException("Cannot invoke operations on a CRDT because the cluster does not contain any data members");
}
try
{
var request = PNCounterAddCodec.EncodeRequest(GetName(), delta, getBeforeUpdate, _observedClock.EntrySet(), targetAddress);
return(InvokeOnTarget(request, targetAddress));
}
catch (Exception ex)
{
Logger.GetLogger(GetType()).Finest("Unable to provide session guarantees when sending operations to " +
targetAddress.ToString() + ", choosing different target. Cause: " +
ex.ToString());
// Make sure that this only affects the local variable of the method
if (excludedAddresses == _emptyAddressList)
{
excludedAddresses = new HashSet <Address>();
}
// Add current/failed address to exclusion list
excludedAddresses.Add(targetAddress);
// Look for the new target address (taking into account exclusion list)
var newTarget = GetCRDTOperationTarget(excludedAddresses);
// Send null target address in case it's uninitialized instance
return(InvokeAddInternal(delta, getBeforeUpdate, excludedAddresses, ex, newTarget));
}
}
