private async Task <StreamMetadataResult> GetStreamMetadataAsync(string streamName,
EventStoreClientOperationOptions operationOptions, UserCredentials?userCredentials = null,
CancellationToken cancellationToken = default)
{
ResolvedEvent metadata;
_log.LogDebug("Read stream metadata for {streamName}.");
try {
metadata = await ReadStreamAsync(Direction.Backwards, SystemStreams.MetastreamOf(streamName),
StreamPosition.End, 1, operationOptions, false, userCredentials, cancellationToken)
.FirstOrDefaultAsync(cancellationToken).ConfigureAwait(false);
} catch (StreamNotFoundException) {
_log.LogWarning("Stream metadata for {streamName} not found.");
return(StreamMetadataResult.None(streamName));
}
return(metadata.Event == null
? StreamMetadataResult.None(streamName)
: StreamMetadataResult.Create(streamName, metadata.OriginalEventNumber,
JsonSerializer.Deserialize <StreamMetadata>(metadata.Event.Data.Span,
StreamMetadataJsonSerializerOptions)));
}
private async Task <StreamMetadataResult> GetStreamMetadataAsync(string streamName,
EventStoreClientOperationOptions operationOptions, UserCredentials userCredentials = default,
CancellationToken cancellationToken = default)
{
ResolvedEvent metadata = default;
try {
metadata = await ReadStreamAsync(Direction.Backwards, SystemStreams.MetastreamOf(streamName), StreamRevision.End, 1,
operationOptions,
resolveLinkTos : false,
userCredentials : userCredentials,
cancellationToken : cancellationToken).FirstOrDefaultAsync(cancellationToken).ConfigureAwait(false);
} catch (StreamNotFoundException) {
return(StreamMetadataResult.None(streamName));
}
return(metadata.Event == null
? StreamMetadataResult.None(streamName)
: StreamMetadataResult.Create(
streamName,
metadata.OriginalEventNumber,
JsonSerializer.Deserialize <StreamMetadata>(metadata.Event.Data, StreamMetadataJsonSerializerOptions)));
}
public async Task subscribe_to_empty_database()
{
var appeared = new TaskCompletionSource <bool>();
var dropped = new TaskCompletionSource <(SubscriptionDroppedReason, Exception)>();
using var subscription = await _fixture.Client
.SubscribeToAllAsync(Position.End, EventAppeared, false, SubscriptionDropped)
.WithTimeout();
Assert.False(appeared.Task.IsCompleted);
if (dropped.Task.IsCompleted)
{
Assert.False(dropped.Task.IsCompleted, dropped.Task.Result.ToString());
}
subscription.Dispose();
var(reason, ex) = await dropped.Task.WithTimeout();
Assert.Equal(SubscriptionDroppedReason.Disposed, reason);
Assert.Null(ex);
Task EventAppeared(StreamSubscription s, ResolvedEvent e, CancellationToken ct)
{
if (!SystemStreams.IsSystemStream(e.OriginalStreamId))
{
appeared.TrySetResult(true);
}
return(Task.CompletedTask);
}
void SubscriptionDropped(StreamSubscription s, SubscriptionDroppedReason reason, Exception ex) =>
dropped.SetResult((reason, ex));
}
public async Task reads_all_existing_events_after_position_and_keep_listening_to_new_ones()
{
var events = _fixture.CreateTestEvents(20).ToArray();
var appeared = new TaskCompletionSource <bool>();
var dropped = new TaskCompletionSource <(SubscriptionDroppedReason, Exception)>();
var beforeEvents = events.Take(10);
var afterEvents = events.Skip(10);
using var enumerator = events.AsEnumerable().GetEnumerator();
enumerator.MoveNext();
var position = await _fixture.Client.ReadAllAsync(Direction.Forwards, Position.Start, 1)
.Select(x => x.OriginalEvent.Position)
.FirstAsync();
foreach (var @event in beforeEvents)
{
await _fixture.Client.AppendToStreamAsync($"stream-{@event.EventId:n}", StreamState.NoStream,
new[] { @event });
}
using var subscription =
await _fixture.Client.SubscribeToAllAsync(position, EventAppeared, false, SubscriptionDropped);
foreach (var @event in afterEvents)
{
await _fixture.Client.AppendToStreamAsync($"stream-{@event.EventId:n}", StreamState.NoStream,
new[] { @event });
}
await appeared.Task.WithTimeout();
Assert.False(dropped.Task.IsCompleted);
subscription.Dispose();
var(reason, ex) = await dropped.Task.WithTimeout();
Assert.Equal(SubscriptionDroppedReason.Disposed, reason);
Assert.Null(ex);
Task EventAppeared(StreamSubscription s, ResolvedEvent e, CancellationToken ct)
{
if (position >= e.OriginalEvent.Position)
{
appeared.TrySetException(new Exception());
}
if (!SystemStreams.IsSystemStream(e.OriginalStreamId))
{
try {
Assert.Equal(enumerator.Current.EventId, e.OriginalEvent.EventId);
if (!enumerator.MoveNext())
{
appeared.TrySetResult(true);
}
} catch (Exception ex) {
appeared.TrySetException(ex);
throw;
}
}
return(Task.CompletedTask);
}
void SubscriptionDropped(StreamSubscription s, SubscriptionDroppedReason reason, Exception ex) =>
dropped.SetResult((reason, ex));
}