Automotive Message Broker Library Documentation

Version

0.13

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Introduction

Automotive Message Broker (AMB) Library documentation outlines the internal classes and structures for building plugins for AMB.

General Architecture

AMB has 3 main parts. Source plugins which provide data, a routing engine that routes data and sink plugins that consume the data.

Properties

AMB defines a number of properties itself. These properties are defined in vehicleproperty.h. The DBus plugin will take many of these properties and combine them in DBus interfaces. The mappings of AMB internal properties to DBus Interface properties can be found in the mappings documentation. This file will come in handy when you want to implement a particular AMB DBus interface in your source plugin.

By default, for any property not explicitly included in a DBus interface, the DBus plugin will generate a custom interface. The pattern is as follows:

CustomProperty = "org.automotive.CustomProperty.CustomProperty"

"org.automotive.CustomProperty is the DBus interface and CustomProperty is a DBus property in that interface.

Plugins

There are two types of plugins: plugins that provide data, called "sources" (AbstractSource) and plugins that consume data, called "sinks" (AbstractSink). A typical source would get data from the vehicle and then translate the raw data into AMB property types. Sinks then subscribe to the property types and do useful things with the data.

Example plugins can be found in plugins/exampleplugin.{h,cpp} for an example source plugin and plugins/examplesink.{h,cpp} for an example sink plugin. There are also many different types of plugins useful for testing and development in the plugins/ directory.

Various plugins have separate documentation found in /usr/share/doc/packages/automotive-message-broker/plugins/.

Creating your own plugin

AMB allows you to create your own plugins. Plugins inherit from either AbstractSource, AbstractSink, or AmbPluginImpl.

It is recommended that new plugins be written using AmbPlugin and AmbPluginImpl.

Routing Engine Plugins

As of 0.12, the routing engine itself can be exchanged for a plugin. This allows users to swap in routing engines with different behaviors, additional security, and custom throttling and filtering features.

The easiest way to get started creating a routing engine plugin would be to look at AbstractRoutingEngine, the base class for all routing engines and the default routing engine in ambd/core.cpp.