public async Task <string> WriteStateAsync(ServiceId serviceId, PersistedMethodId methodId, MethodExecutionState state)
{
var tableName = GetTableQualifiedName(serviceId, methodId);
var key = new StorageRecord
{
service = serviceId.Name,
method = methodId.Name,
intent_id = methodId.IntentId
};
var record = new StorageRecord
{
etag = DateTimeOffset.UtcNow.Ticks,
status = (int)Statuses.Paused,
updated_at = DateTimeOffset.Now,
caller_service = state.Caller?.Service?.Name,
caller_proxy = state.Caller?.Service?.Proxy,
caller_method = state.Caller?.Method?.Name,
caller_event = state.Caller?.Event?.Name,
caller_intent_id = state.Caller?.IntentId,
format = _serializer.Format,
execution_state = _serializer.SerializeToBytes(state),
};
var query = new StringBuilder("UPDATE ").Append(tableName);
query.Append(" SET ");
WriteValues(query, record, delimiter: ", ");
query.Append(" WHERE ");
WriteValues(query, key, delimiter: " AND ");
if (!string.IsNullOrEmpty(methodId.ETag))
{
query.Append(" IF etag = ").AppendCqlText(methodId.ETag);
}
var result = await ExecuteQueryAsync(serviceId, methodId, query.ToString());
if (result != null)
{
var row = result.FirstOrDefault();
if (row != null && !row.GetValue <bool>("[applied]"))
{
var actualETag = row.GetValueOrDefault <long>("etag");
throw new ETagMismatchException(methodId.ETag, actualETag.ToString());
}
}
return(record.etag.ToString());
}
public async Task <ITaskResult> TryReadResultAsync(ServiceId serviceId, MethodId methodId, string intentId, Type resultValueType, CancellationToken ct)
{
var tableName = GetTableQualifiedName(serviceId, methodId);
var key = new StorageRecord
{
service = serviceId.Name,
method = methodId.Name,
intent_id = intentId
};
var query = new StringBuilder("SELECT status, outcome, format, task_result, result, error FROM ")
.Append(tableName).Append(" WHERE ");
WriteValues(query, key, delimiter: " AND ");
var result = await ExecuteQueryAsync(serviceId, methodId, query.ToString());
var row = result.FirstOrDefault();
if (row == null)
{
return(null);
}
var record = ReadValues(row);
if (!record.outcome.HasValue)
{
return(null);
}
if (record.outcome.Value == (int)Outcomes.Canceled)
{
return(TaskResult.Create(resultValueType, null, null, isCanceled: true));
}
var serializer = !string.IsNullOrEmpty(record.format)
? _serializerProvider.GetSerializer(record.format)
: _serializer;
var taskResult = TaskResult.CreateEmpty(resultValueType);
serializer.Populate(record.task_result, (IValueContainer)taskResult);
return(taskResult);
}
public async Task <MethodExecutionState> ReadStateAsync(ServiceId serviceId, PersistedMethodId methodId, CancellationToken ct)
{
var tableName = GetTableQualifiedName(serviceId, methodId);
var key = new StorageRecord
{
service = serviceId.Name,
method = methodId.Name,
intent_id = methodId.IntentId
};
var query = new StringBuilder("SELECT * FROM ")
.Append(tableName).Append(" WHERE ");
WriteValues(query, key, delimiter: " AND ");
var result = await ExecuteQueryAsync(serviceId, methodId, query.ToString());
var row = result.FirstOrDefault();
if (row == null)
{
throw new StateNotFoundException(serviceId, methodId);
}
var record = ReadValues(row);
if (record.status.HasValue && record.status.Value != (int)Statuses.Paused)
{
throw new InvalidOperationException("Method is not paused");
}
if (!(record.execution_state?.Length > 0))
{
throw new InvalidOperationException("Empty state data");
}
var serializer = !string.IsNullOrEmpty(record.format)
? _serializerProvider.GetSerializer(record.format)
: _serializer;
return(serializer.Deserialize <MethodExecutionState>(record.execution_state));
}
public async Task WriteResultAsync(ServiceId serviceId, MethodId methodId, string intentId, ITaskResult result)
{
var tableName = GetTableQualifiedName(serviceId, methodId);
var key = new StorageRecord
{
service = serviceId.Name,
method = methodId.Name,
intent_id = intentId
};
var record = new StorageRecord
{
etag = DateTimeOffset.UtcNow.Ticks,
status = (int)Statuses.Complete,
outcome = (int)(result.IsCanceled ? Outcomes.Canceled : (result.IsFaulted() ? Outcomes.Failed : Outcomes.Succeeded)),
updated_at = DateTimeOffset.Now,
format = _serializer.Format,
task_result = _serializer.SerializeToBytes(result)
};
var query = new StringBuilder("UPDATE ").Append(tableName);
if (_settings.ResultTTL.HasValue)
{
query.Append(" USING TTL ").Append((int)_settings.ResultTTL.Value.TotalSeconds);
}
query.Append(" SET ");
WriteValues(query, record, delimiter: ", ");
query.Append(", execution_state = null, method_state = null, flow_context = null, continuation = null, continuation_state = null");
query.Append(" WHERE ");
WriteValues(query, key, delimiter: " AND ");
await ExecuteQueryAsync(serviceId, methodId, query.ToString());
}
private static StringBuilder WriteValues(StringBuilder sb, StorageRecord record, string delimiter)
{
if (record.service != null)
{
sb.Append("service = '").Append(record.service).Append('\'').Append(delimiter);
}
if (record.method != null)
{
sb.Append("method = '").Append(record.method).Append('\'').Append(delimiter);
}
if (record.intent_id != null)
{
sb.Append("intent_id = '").Append(record.intent_id).Append('\'').Append(delimiter);
}
if (record.etag != null)
{
sb.Append("etag = ").Append(record.etag).Append(delimiter);
}
if (record.status.HasValue)
{
sb.Append("status = ").Append(record.status.Value).Append(delimiter);
}
if (record.outcome.HasValue)
{
sb.Append("outcome = ").Append(record.outcome.Value).Append(delimiter);
}
if (record.last_intent_id != null)
{
sb.Append("last_intent_id = '").Append(record.last_intent_id).Append(delimiter);
}
if (record.invoked_at.HasValue)
{
sb.Append("invoked_at = ").AppendCqlTimestamp(record.invoked_at.Value).Append(delimiter);
}
if (record.started_at.HasValue)
{
sb.Append("started_at = ").AppendCqlTimestamp(record.started_at.Value).Append(delimiter);
}
if (record.updated_at.HasValue)
{
sb.Append("updated_at = ").AppendCqlTimestamp(record.updated_at.Value).Append(delimiter);
}
if (record.duration.HasValue)
{
sb.Append("duration = ").AppendCqlDuration(record.duration.Value).Append(delimiter);
}
if (record.cancel_at.HasValue)
{
sb.Append("cancel_at = ").AppendCqlTimestamp(record.cancel_at.Value).Append(delimiter);
}
if (record.cancellation_id != null)
{
sb.Append("cancellation_id = '").Append(record.cancellation_id).Append('\'');
}
if (record.transition_count.HasValue)
{
sb.Append("transition_count = ").Append(record.transition_count.Value).Append(delimiter);
}
if (record.caller_service != null)
{
sb.Append("caller_service = '").Append(record.caller_service).Append('\'').Append(delimiter);
}
if (record.caller_proxy != null)
{
sb.Append("caller_proxy = '").Append(record.caller_proxy).Append('\'').Append(delimiter);
}
if (record.caller_method != null)
{
sb.Append("caller_method = '").Append(record.caller_method).Append('\'').Append(delimiter);
}
if (record.caller_event != null)
{
sb.Append("caller_event = '").Append(record.caller_event).Append('\'').Append(delimiter);
}
if (record.caller_intent_id != null)
{
sb.Append("caller_intent_id = '").Append(record.caller_intent_id).Append('\'').Append(delimiter);
}
if (record.format != null)
{
sb.Append("format = '").Append(record.format).Append('\'').Append(delimiter);
}
if (record.execution_state?.Length > 0)
{
sb.Append("execution_state = ").AppendCqlBlob(record.execution_state).Append(delimiter);
}
if (record.method_state?.Length > 0)
{
sb.Append("method_state = ").AppendCqlBlob(record.method_state).Append(delimiter);
}
if (record.flow_context?.Length > 0)
{
sb.Append("flow_context = ").AppendCqlBlob(record.flow_context).Append(delimiter);
}
if (record.task_result?.Length > 0)
{
sb.Append("task_result = ").AppendCqlBlob(record.task_result).Append(delimiter);
}
if (record.result?.Length > 0)
{
sb.Append("result = ").AppendCqlBlob(record.result).Append(delimiter);
}
if (record.error?.Length > 0)
{
sb.Append("error = ").AppendCqlBlob(record.error).Append(delimiter);
}
if (record.continuation?.Length > 0)
{
sb.Append("continuation = ").AppendCqlBlob(record.continuation).Append(delimiter);
}
if (record.continuation_state?.Length > 0)
{
sb.Append("continuation_state = ").AppendCqlBlob(record.continuation_state).Append(delimiter);
}
// Remove last delimiter
sb.Remove(sb.Length - delimiter.Length, delimiter.Length);
return(sb);
}
