public Task <EventStoreSubscription> FilteredSubscribeToAllAsync(bool resolveLinkTos, Filter filter,
Func <EventStoreSubscription, ResolvedEvent, Task> eventAppeared,
Func <EventStoreSubscription, Position, Task> checkpointReached, int checkpointInterval,
Action <EventStoreSubscription, SubscriptionDropReason, Exception> subscriptionDropped = null,
UserCredentials userCredentials = null)
{
Ensure.NotNull(eventAppeared, nameof(eventAppeared));
Ensure.NotNull(filter, nameof(filter));
Ensure.NotNull(checkpointReached, nameof(checkpointReached));
if (checkpointInterval <= 0 && checkpointInterval != DontReportCheckpointReached)
{
throw new ArgumentOutOfRangeException(nameof(checkpointInterval));
}
var source = TaskCompletionSourceFactory.Create <EventStoreSubscription>();
_handler.EnqueueMessage(new StartFilteredSubscriptionMessage(source, string.Empty, resolveLinkTos,
checkpointInterval, filter, userCredentials, eventAppeared, checkpointReached,
subscriptionDropped, Settings.MaxRetries, Settings.OperationTimeout));
return(source.Task);
}
public async Task <AllEventsSlice> FilteredReadAllEventsBackwardAsync(Position position, int maxCount,
bool resolveLinkTos, Filter filter, int maxSearchWindow, UserCredentials userCredentials = null)
{
Ensure.Positive(maxCount, "maxCount");
Ensure.Positive(maxSearchWindow, nameof(maxSearchWindow));
Ensure.GreaterThanOrEqualTo(maxSearchWindow, maxCount, nameof(maxSearchWindow));
Ensure.NotNull(filter, nameof(filter));
if (maxCount > ClientApiConstants.MaxReadSize)
{
throw new ArgumentException(string.Format(
"Count should be less than {0}. For larger reads you should page.",
ClientApiConstants.MaxReadSize));
}
var source = TaskCompletionSourceFactory.Create <AllEventsSlice>();
var operation = new FilteredReadAllEventsBackwardOperation(Settings.Log, source, position, maxCount,
resolveLinkTos, Settings.RequireLeader, maxSearchWindow, filter.Value, userCredentials);
await EnqueueOperation(operation).ConfigureAwait(false);
return(await source.Task.ConfigureAwait(false));
}
/// <summary>
/// Sometimes, we need to manually send more requests:
/// - When more requests are added to the DicomClient
/// - When a pending request has completed, perhaps freeing up an async operations slot on the association
/// </summary>
private async Task KeepSendingUntilAllRequestsHaveCompletedAsync()
{
while (true)
{
var cancellationTaskCompletionSource = TaskCompletionSourceFactory.Create <bool>();
using (_sendRequestsCancellationTokenSource.Token.Register(() => cancellationTaskCompletionSource.SetResult(true)))
{
/*
* This event will be triggered when the DicomClientConnection believes it has finished its work by triggering the OnSendQueueEmpty event
*/
var sendMoreRequests = _sendMoreRequests.WaitAsync();
/*
* This event will be triggered when the CancellationToken passed into SendAsync is cancelled
*/
var onCancel = cancellationTaskCompletionSource.Task;
/*
* This event will be triggered when the pending queue becomes empty
*/
var allRequestsHaveCompleted = _allRequestsHaveCompletedTaskCompletionSource.Task;
var winner = await Task.WhenAny(allRequestsHaveCompleted, sendMoreRequests, onCancel).ConfigureAwait(false);
if (winner == allRequestsHaveCompleted || winner == onCancel)
{
return;
}
}
try
{
if (Interlocked.CompareExchange(ref _sending, 1, 0) == 0)
{
try
{
if (!_dicomClient.QueuedRequests.IsEmpty)
{
if (_numberOfSentRequests >= _maximumNumberOfRequestsPerAssociation)
{
_dicomClient.Logger.Debug(
$"[{this}] DICOM client has reached the maximum number of requests for this association and is still waiting for the sent requests to complete");
}
else
{
_dicomClient.Logger.Debug($"[{this}] DICOM client has more queued requests, sending those now...");
await SendRequests().ConfigureAwait(false);
}
}
if (Connection.IsSendNextMessageRequired)
{
_dicomClient.Logger.Debug($"[{this}] DICOM client connection still has unsent requests, sending those now...");
await Connection.SendNextMessageAsync().ConfigureAwait(false);
}
}
finally
{
Interlocked.Exchange(ref _sending, 0);
}
}
}
finally
{
_sendMoreRequests.Reset();
}
}
}
public DicomClientConnectState(DicomClient dicomClient)
{
_dicomClient = dicomClient ?? throw new ArgumentNullException(nameof(dicomClient));
_cancellationRequestedTaskCompletionSource = TaskCompletionSourceFactory.Create <bool>();
_disposables = new List <IDisposable>();
}
