public async Task <IChunk> ReadSingleBackwardAsync(string partitionId, long fromUpperIndexInclusive, CancellationToken cancellationToken)
{
using (var connection = Connect())
{
await connection.OpenAsync(cancellationToken).ConfigureAwait(false);
using (var command = new SqlCommand(_options.GetLastChunkScript(), connection))
{
command.Parameters.AddWithValue("@PartitionId", partitionId);
command.Parameters.AddWithValue("@toUpperIndexInclusive", fromUpperIndexInclusive);
using (var reader = await command.ExecuteReaderAsync(cancellationToken).ConfigureAwait(false))
{
if (!reader.HasRows)
{
return(null);
}
await reader.ReadAsync(cancellationToken).ConfigureAwait(false);
var chunk = new MsSqlChunk
{
Position = reader.GetInt64(0),
PartitionId = reader.GetString(1),
Index = reader.GetInt64(2),
Payload = _options.Serializer.Deserialize(reader.GetString(3)),
OperationId = reader.GetString(4),
Deleted = reader.GetBoolean(5)
};
return(chunk);
}
}
}
}
private async Task PushToSubscriber(SqlCommand command, long start, ISubscription subscription, CancellationToken cancellationToken)
{
long position = 0;
await subscription.OnStart(start).ConfigureAwait(false);
using (var reader = await command.ExecuteReaderAsync(cancellationToken).ConfigureAwait(false))
{
while (await reader.ReadAsync(cancellationToken).ConfigureAwait(false))
{
position = reader.GetInt64(0);
var chunk = new MsSqlChunk
{
Position = position,
PartitionId = reader.GetString(1),
Index = reader.GetInt64(2),
Payload = _options.Serializer.Deserialize(reader.GetString(3)),
OperationId = reader.GetString(4),
Deleted = reader.GetBoolean(5)
};
if (!await subscription.OnNext(chunk).ConfigureAwait(false))
{
await subscription.Stopped(chunk.Position).ConfigureAwait(false);
return;
}
}
}
await subscription.Completed(position).ConfigureAwait(false);
}
private async Task PushToSubscriber(SqlCommand command, long start, ISubscription subscription, bool broadcastPosition, CancellationToken cancellationToken)
{
long indexOrPosition = 0;
await subscription.OnStartAsync(start).ConfigureAwait(false);
try
{
using (var reader = await command.ExecuteReaderAsync(cancellationToken).ConfigureAwait(false))
{
while (await reader.ReadAsync(cancellationToken).ConfigureAwait(false))
{
var chunk = new MsSqlChunk
{
Position = reader.GetInt64(0),
PartitionId = reader.GetString(1),
Index = reader.GetInt64(2),
OperationId = reader.GetString(4),
};
indexOrPosition = broadcastPosition ? chunk.Position : chunk.Index;
// to handle exceptions with correct position
chunk.Payload = _options.Serializer.Deserialize(reader.GetString(3));
if (!await subscription.OnNextAsync(chunk).ConfigureAwait(false))
{
await subscription.StoppedAsync(chunk.Position).ConfigureAwait(false);
return;
}
}
}
await subscription.CompletedAsync(indexOrPosition).ConfigureAwait(false);
}
catch (Exception e)
{
await subscription.OnErrorAsync(indexOrPosition, e).ConfigureAwait(false);
}
}
private async Task <MsSqlChunk> ReadSingleChunk(SqlCommand command, CancellationToken cancellationToken)
{
using (var reader = await command.ExecuteReaderAsync(cancellationToken).ConfigureAwait(false))
{
if (!reader.HasRows)
{
return(null);
}
await reader.ReadAsync(cancellationToken).ConfigureAwait(false);
var chunk = new MsSqlChunk
{
Position = reader.GetInt64(0),
PartitionId = reader.GetString(1),
Index = reader.GetInt64(2),
OperationId = reader.GetString(4),
Payload = _options.Serializer.Deserialize(reader.GetString(3)),
};
return(chunk);
}
}
public async Task <IChunk> AppendAsync(
string partitionId,
long index,
object payload,
string operationId,
CancellationToken cancellationToken)
{
if (index == -1)
{
index = Interlocked.Increment(ref USE_SEQUENCE_INSTEAD);
}
var chunk = new MsSqlChunk()
{
PartitionId = partitionId,
Index = index,
Payload = payload,
OperationId = operationId ?? Guid.NewGuid().ToString()
};
string textPayload = _options.Serializer.Serialize(payload);
try
{
using (var connection = Connect())
{
await connection.OpenAsync(cancellationToken).ConfigureAwait(false);
using (var command = new SqlCommand(_options.GetPersistScript(), connection))
{
command.Parameters.AddWithValue("@PartitionId", partitionId);
command.Parameters.AddWithValue("@Index", index);
command.Parameters.AddWithValue("@OperationId", chunk.OperationId);
command.Parameters.AddWithValue("@Payload", textPayload);
chunk.Position = (long)await command.ExecuteScalarAsync(cancellationToken).ConfigureAwait(false);
}
}
}
catch (SqlException ex)
{
if (ex.Number == DUPLICATED_INDEX_EXCEPTION)
{
if (ex.Message.Contains("_IDX"))
{
throw new DuplicateStreamIndexException(partitionId, index);
}
if (ex.Message.Contains("_OPID"))
{
_logger.LogInformation($"Skipped duplicated chunk on '{partitionId}' by operation id '{operationId}'");
return(null);
}
}
_logger.LogError(ex.Message);
throw;
}
return(chunk);
}