/// <summary> Read state data function for this storage provider.</summary>
/// <see cref="IGrainStorage.ReadStateAsync(string, GrainReference, IGrainState)"/>.
public async Task ReadStateAsync(string grainType, GrainReference grainReference, IGrainState grainState)
{
//It assumed these parameters are always valid. If not, an exception will be thrown, even if not as clear
//as with explicitly checked parameters.
var grainId = GrainIdAndExtensionAsString(grainReference);
var baseGrainType = ExtractBaseClass(grainType);
if (logger.IsEnabled(LogLevel.Trace))
{
logger.Trace((int)RelationalStorageProviderCodes.RelationalProviderReading, LogString("Reading grain state", serviceId, this.name, grainState.ETag, baseGrainType, grainId.ToString()));
}
try
{
SerializationChoice choice = StorageSerializationPicker.PickDeserializer(serviceId, this.name, baseGrainType, grainReference, grainState, null);
if (choice.Deserializer == null)
{
var errorString = LogString("No deserializer found", serviceId, this.name, grainState.ETag, baseGrainType, grainId.ToString());
logger.Error((int)RelationalStorageProviderCodes.RelationalProviderNoDeserializer, errorString);
throw new InvalidOperationException(errorString);
}
var commandBehavior = choice.PreferStreaming ? CommandBehavior.SequentialAccess : CommandBehavior.Default;
var grainIdHash = HashPicker.PickHasher(serviceId, this.name, baseGrainType, grainReference, grainState).Hash(grainId.GetHashBytes());
var grainTypeHash = HashPicker.PickHasher(serviceId, this.name, baseGrainType, grainReference, grainState).Hash(Encoding.UTF8.GetBytes(baseGrainType));
var readRecords = (await Storage.ReadAsync(CurrentOperationalQueries.ReadFromStorage, (command =>
{
command.AddParameter("GrainIdHash", grainIdHash);
command.AddParameter("GrainIdN0", grainId.N0Key);
command.AddParameter("GrainIdN1", grainId.N1Key);
command.AddParameter("GrainTypeHash", grainTypeHash);
command.AddParameter("GrainTypeString", baseGrainType);
command.AddParameter("GrainIdExtensionString", grainId.StringKey);
command.AddParameter("ServiceId", serviceId);
}), async(selector, resultSetCount, token) =>
{
object storageState = null;
int?version;
if (choice.PreferStreaming)
{
//When streaming via ADO.NET, using CommandBehavior.SequentialAccess, the order of
//the columns on how they are read needs to be exactly this.
const int binaryColumnPositionInSelect = 0;
const int xmlColumnPositionInSelect = 1;
const int jsonColumnPositionInSelect = 2;
var streamSelector = (DbDataReader)selector;
if (!(await streamSelector.IsDBNullAsync(binaryColumnPositionInSelect)))
{
using (var downloadStream = streamSelector.GetStream(binaryColumnPositionInSelect, Storage))
{
storageState = choice.Deserializer.Deserialize(downloadStream, grainState.Type);
}
}
if (!(await streamSelector.IsDBNullAsync(xmlColumnPositionInSelect)))
{
using (var downloadStream = streamSelector.GetTextReader(xmlColumnPositionInSelect))
{
storageState = choice.Deserializer.Deserialize(downloadStream, grainState.Type);
}
}
if (!(await streamSelector.IsDBNullAsync(jsonColumnPositionInSelect)))
{
using (var downloadStream = streamSelector.GetTextReader(jsonColumnPositionInSelect))
{
storageState = choice.Deserializer.Deserialize(downloadStream, grainState.Type);
}
}
version = await streamSelector.GetValueAsync <int?>("Version");
}
else
{
//All but one of these should be null. All will be read and an appropriate deserializer picked.
//NOTE: When streaming will be implemented, it is worthwhile to optimize this so that the defined
//serializer will be picked and then streaming tried according to its tag.
object payload;
payload = selector.GetValueOrDefault <byte[]>("PayloadBinary");
if (payload == null)
{
payload = selector.GetValueOrDefault <string>("PayloadXml");
}
if (payload == null)
{
payload = selector.GetValueOrDefault <string>("PayloadJson");
}
if (payload != null)
{
storageState = choice.Deserializer.Deserialize(payload, grainState.Type);
}
version = selector.GetNullableInt32("Version");
}
return(Tuple.Create(storageState, version?.ToString(CultureInfo.InvariantCulture)));
}, CancellationToken.None, commandBehavior).ConfigureAwait(false)).SingleOrDefault();
object state = readRecords != null ? readRecords.Item1 : null;
string etag = readRecords != null ? readRecords.Item2 : null;
if (state == null)
{
logger.Info((int)RelationalStorageProviderCodes.RelationalProviderNoStateFound, LogString("Null grain state read (default will be instantiated)", serviceId, this.name, grainState.ETag, baseGrainType, grainId.ToString()));
state = Activator.CreateInstance(grainState.Type);
}
grainState.State = state;
grainState.ETag = etag;
if (logger.IsEnabled(LogLevel.Trace))
{
logger.Trace((int)RelationalStorageProviderCodes.RelationalProviderRead, LogString("Read grain state", serviceId, this.name, grainState.ETag, baseGrainType, grainId.ToString()));
}
}
catch (Exception ex)
{
logger.Error((int)RelationalStorageProviderCodes.RelationalProviderReadError, LogString("Error reading grain state", serviceId, this.name, grainState.ETag, baseGrainType, grainId.ToString(), ex.Message), ex);
throw;
}
}
/// <summary> Write state data function for this storage provider.</summary>
/// <see cref="IStorageProvider.WriteStateAsync"/>
public async Task WriteStateAsync(string grainType, GrainReference grainReference, IGrainState grainState)
{
//It assumed these parameters are always valid. If not, an exception will be thrown, even if not as clear
//as with explicitly checked parameters.
var data = grainState.State;
var grainId = GrainIdAndExtensionAsString(grainReference);
var baseGrainType = ExtractBaseClass(grainType);
if (logger.IsEnabled(LogLevel.Trace))
{
logger.Trace((int)RelationalStorageProviderCodes.RelationalProviderWriting, LogString("Writing grain state", ServiceId, Name, grainState.ETag, baseGrainType, grainId.ToString()));
}
string storageVersion = null;
try
{
var grainIdHash = HashPicker.PickHasher(ServiceId, Name, baseGrainType, grainReference, grainState).Hash(grainId.GetHashBytes());
var grainTypeHash = HashPicker.PickHasher(ServiceId, Name, baseGrainType, grainReference, grainState).Hash(Encoding.UTF8.GetBytes(baseGrainType));
var writeRecord = await Storage.ReadAsync(CurrentOperationalQueries.WriteToStorage, command =>
{
command.AddParameter("GrainIdHash", grainIdHash);
command.AddParameter("GrainIdN0", grainId.N0Key);
command.AddParameter("GrainIdN1", grainId.N1Key);
command.AddParameter("GrainTypeHash", grainTypeHash);
command.AddParameter("GrainTypeString", baseGrainType);
command.AddParameter("GrainIdExtensionString", grainId.StringKey);
command.AddParameter("ServiceId", ServiceId);
command.AddParameter("GrainStateVersion", !string.IsNullOrWhiteSpace(grainState.ETag) ? int.Parse(grainState.ETag, CultureInfo.InvariantCulture) : default(int?));
SerializationChoice serializer = StorageSerializationPicker.PickSerializer(ServiceId, Name, baseGrainType, grainReference, grainState);
command.AddParameter("PayloadBinary", (byte[])(serializer.Serializer.Tag == UseBinaryFormatPropertyName ? serializer.Serializer.Serialize(data) : null));
command.AddParameter("PayloadJson", (string)(serializer.Serializer.Tag == UseJsonFormatPropertyName ? serializer.Serializer.Serialize(data) : null));
command.AddParameter("PayloadXml", (string)(serializer.Serializer.Tag == UseXmlFormatPropertyName ? serializer.Serializer.Serialize(data) : null));
}, (selector, resultSetCount, token) =>
{ return(Task.FromResult(selector.GetValueOrDefault <int?>("NewGrainStateVersion").ToString())); }, CancellationToken.None).ConfigureAwait(false);
storageVersion = writeRecord.SingleOrDefault();
}
catch (Exception ex)
{
logger.Error((int)RelationalStorageProviderCodes.RelationalProviderWriteError, LogString("Error writing grain state", ServiceId, Name, grainState.ETag, baseGrainType, grainId.ToString(), ex.Message), ex);
throw;
}
const string OperationString = "WriteState";
var inconsistentStateException = CheckVersionInconsistency(OperationString, ServiceId, Name, storageVersion, grainState.ETag, baseGrainType, grainId.ToString());
if (inconsistentStateException != null)
{
throw inconsistentStateException;
}
//No errors found, the version of the state held by the grain can be updated.
grainState.ETag = storageVersion;
if (logger.IsEnabled(LogLevel.Trace))
{
logger.Trace((int)RelationalStorageProviderCodes.RelationalProviderWrote, LogString("Wrote grain state", ServiceId, Name, grainState.ETag, baseGrainType, grainId.ToString()));
}
}