public async Task AppendExclusive(string streamKey, CancellationToken token, params object[] events)
{
_store.Events.EnsureAsStringStorage(_session);
var cmd = new NpgsqlCommand($"select version from {_store.Events.DatabaseSchemaName}.mt_streams where id = :id for update")
.With("id", streamKey);
await _session.BeginTransactionAsync(token).ConfigureAwait(false);
var version = await readVersionFromExistingStream(streamKey, token, cmd).ConfigureAwait(false);
var action = Append(streamKey, events);
action.ExpectedVersionOnServer = version;
}
public async Task <IEventStream <TDoc> > FetchForWriting(DocumentSessionBase session, TId id, bool forUpdate, CancellationToken cancellation = default)
{
var selector = await _identityStrategy.EnsureAggregateStorageExists <TDoc>(session, cancellation).ConfigureAwait(false);
if (forUpdate)
{
await session.BeginTransactionAsync(cancellation).ConfigureAwait(false);
}
var command = _identityStrategy.BuildCommandForReadingVersionForStream(id, forUpdate);
var builder = new CommandBuilder(command);
builder.Append(";");
var handler = _identityStrategy.BuildEventQueryHandler(id, selector);
handler.ConfigureCommand(builder, session);
long version = 0;
try
{
using var reader = await session.ExecuteReaderAsync(builder.Compile(), cancellation).ConfigureAwait(false);
if (await reader.ReadAsync(cancellation).ConfigureAwait(false))
{
version = await reader.GetFieldValueAsync <long>(0, cancellation).ConfigureAwait(false);
}
await reader.NextResultAsync(cancellation).ConfigureAwait(false);
var events = await handler.HandleAsync(reader, session, cancellation).ConfigureAwait(false);
var document = await _aggregator.BuildAsync(events, session, default, cancellation).ConfigureAwait(false);
public async Task <IEventStream <TDoc> > FetchForWriting(DocumentSessionBase session, TId id, bool forUpdate, CancellationToken cancellation = default)
{
await _identityStrategy.EnsureAggregateStorageExists <TDoc>(session, cancellation).ConfigureAwait(false);
await session.Database.EnsureStorageExistsAsync(typeof(TDoc), cancellation).ConfigureAwait(false);
if (forUpdate)
{
await session.BeginTransactionAsync(cancellation).ConfigureAwait(false);
}
var command = _identityStrategy.BuildCommandForReadingVersionForStream(id, forUpdate);
var builder = new CommandBuilder(command);
builder.Append(";");
var handler = new LoadByIdHandler <TDoc, TId>(_storage, id);
handler.ConfigureCommand(builder, session);
long version = 0;
try
{
using var reader = await session.ExecuteReaderAsync(builder.Compile(), cancellation).ConfigureAwait(false);
if (await reader.ReadAsync(cancellation).ConfigureAwait(false))
{
version = await reader.GetFieldValueAsync <long>(0, cancellation).ConfigureAwait(false);
}
await reader.NextResultAsync(cancellation).ConfigureAwait(false);
var document = await handler.HandleAsync(reader, session, cancellation).ConfigureAwait(false);
return(version == 0
? _identityStrategy.StartStream <TDoc>(document, session, id, cancellation)
: _identityStrategy.AppendToStream <TDoc>(document, session, id, version, cancellation));
}
catch (Exception e)
{
if (e.Message.Contains(MartenCommandException.MaybeLockedRowsMessage))
{
throw new StreamLockedException(id, e.InnerException);
}
throw;
}
}
