Socket Back-End Framework

Architecture

Relay Model

Request-Response Model

(deprecated)

Features

• Each configurable module has a clear responsibility.
• Business logic decouples from transport infrastructure and pipelines.
• It both supports the relay network model or the request-response network model.
• Controllers can have different pipeline domains sent application messages.
• It supports custom protocols in nature.

How to use

The project SocketBackendFramework.Relay.Sample gives a simple example of using the framework. A new project can take this sample as a boilerplate.

Components

• TransportAgent := a wrapped socket handler.
• TransportMapper := an object that organizes many transportAgents.
  • It is only configurable from config.json, not from user code.
• PacketContext := an object that carries information and flows between a transportMapper and one of its transportAgents.
• MiddlewareContext := an object that carries information and flows within a pipeline.
  • Users should implement it.
  • Usually, a middlewareContext should bring a packetContext.
• ContextAdaptor := a convertor between packetContexts and midlewareContexts.
  • It acts as an adaptor between a pipeline and a transportMapper.
    • TransportMappers only accept packetContexts.
    • Pipelines only accept middlewareContexts.
• Pipeline := a stack-like data structure containing several middlewares.
  • Those middlewares decorate the middlewareContexts that pass through the pipeline.
  • When the middlewareContexts go to the bottom of the pipeline, they should contain information ready to use by controllers.
  • When the middlewareContexts go to the top of the pipeline, each should contain a complete packetContext ready to use by transportAgents.
• PipelineDomain := a virtual area including a pipeline and a dedicated transportMapper.
• Workflow := a virtual area that owns a complete and independent back-end server.
  • No data exchange is allowed between workflows.
• WorkflowPool := a virtual area that collects all the running workflows.
• Controller := a object that majorly involves business logic.

Notices

• Disposal of socket handlers
  • When disconnection hits a socket handler, the organizer of many socket handlers should dispose the socket handler.
    • The organizer can be Listener or TransportMapper.
      • Listener disposes TcpSessionHandler.
      • TransportMapper disposes TransportClient.
  • A timeout only directly activates a disconnection, not a disposal.
  • When an organizer decides to dispose one of the socket handlers, it should do the disposal before telling controllers about the disconnection.