is the adapter bidirectional?

darch

The adapter allows to send notifications with _listener.Update.
Is there a way to listen for events?

Dario Crivelli

If you mean client-originated events, yes, the involved method is NotifyUserMessage on the Metadata Adapter.
Note that client-originated events are related with the client identity, so they don't pertain to the Data Adapter, but rather to the Metadata Adapter, which manages the user activity.

darch

thx Dario,

I followed http://www.lightstreamer.com/docs/articles/DotNET-Data-Adapter_Tutorial_Colosseo/index.htm , sessions is really needed I'd need to get a sort of session_id to send different data to each (clients)

I guess I must start by implementing IMetadataProvider

Thx for the help

Dario Crivelli

A more complete example is the .NET Portfolio Demo Adapters, under
DOCS-SDKs\sdk_adapter_dotnet\examples\Remote_Portfolio_Adapters
in the distribution package.
There, the client-originated messages are used to simulate buy/sell operations.

darch

I was using the c++ or c# remote architecture because my data feeder is a c++/c# dll API.
This whole architecture seems rather complex, I'd be tempted to wrap the feed API in JNI code and use the classic and simpler lighstreamer codes.
Do you think one solution is better?

Giuseppe Corti

Building Java inprocess Data Adapter and MetaData Adpater using C++ or C# dll via JNI is not prohibited and could be a workable solution.

However, I would recommend the solution implemented by the remote adapter, this given the following considerations.
Please note that the architecture with the remote adapters may seem more complicated but it leaves you with the only task of developing the adapters based on the Lightstreamer .NET library and you can forget about direct socket programming and network protocol. Furthermore, in this way you can add metadata and data adapters in a single process facilitating communication between them.

Finally I would like to mention some potential issues regarding the use of JNI, the first concerns the possible crash of the external dll that sharing the same process will crash the Lighstreamer kernel too; the second concerns the mixed sharing of heap memory between JNI and Java.

Hope that helps.

darch

thx, I think I'll try to do it like you say, though I'd have preferred Java :Smile_Ad:

the c++ portfolio adapter seems close to what I need (a LS app that tracks tick prices and orders per client, with a c++ Metatrader4 library)
Each user has their own data, users don't share portfolio, a bit different so
I would like to simplify it, because I'm not sure I need a Portfolio class that links the metadataAdapter to dataAdapter
the issue is incoming messages comes in metadataAdapter, and the rest is in dataAdapter