private void LogFunctionStartedWhenPreviouslyQueued(FunctionInstanceSnapshot snapshot, string etag)
{
// LogFunctionStarted and LogFunctionCompleted may run concurrently. LogFunctionQueued does not run
// concurrently. Ensure LogFunctionStarted wins over LogFunctionQueued but loses to LogFunctionCompleted by
// doing a Replace with ETag check that will fail if the entity has been changed.
// LogFunctionCompleted wins by doing a Replace without an ETag check, so it will replace the
// LogFunctionStarted (or Queued) record, if any.
// Ignore the return value: if the ETag doesn't match, LogFunctionCompleted already ran, so there's no work
// to do here.
_store.TryUpdate(GetId(snapshot), etag, snapshot);
}
private bool TryUpdateEntity(string functionId, Action <FunctionStatistics> modifier)
{
IConcurrentDocument <FunctionStatistics> result = _store.Read(functionId);
if (result == null || result.Document == null)
{
FunctionStatistics statistics = new FunctionStatistics();
modifier.Invoke(statistics);
return(_store.TryCreate(functionId, statistics));
}
else
{
FunctionStatistics statistics = result.Document;
modifier.Invoke(statistics);
return(_store.TryUpdate(functionId, result.ETag, statistics));
}
}