Rebus

An Elixir implementation of the D-Bus message protocol.

Rebus provides a clean, Elixir-native interface for communicating over D-Bus, the inter-process communication (IPC) and remote procedure call (RPC) mechanism that is standard on Linux desktop systems.

Features

• D-Bus Wire Protocol Compliance - Full implementation of the D-Bus specification including 8-byte struct alignment
• Multiple Connection Types - Support for TCP/IP and Unix domain socket connections
• Signal Handling - Register handlers to receive D-Bus signals
• Message Encoding/Decoding - Robust serialization of D-Bus messages with proper type handling
• Supervised Connections - Fault-tolerant connection management with automatic supervision
• Comprehensive Testing - Extensive test suite with 200+ tests ensuring reliability

Quick Start

# Connect to a D-Bus endpoint
{:ok, conn} = Rebus.connect(:session)

# Add a signal handler to receive D-Bus signals
ref = Rebus.add_signal_handler(conn)

# Create and send a D-Bus message
{:ok, message} = Rebus.Message.new(:method_call,
  path: "/com/example/Object",
  interface: "com.example.Interface", 
  member: "TestMethod",
  body: [42, "hello"],
  signature: "is"
)

# Clean up when done
Rebus.delete_signal_handler(conn, ref)

Architecture

Rebus is built with a modular architecture:

• Rebus - Main API module for establishing connections and managing signal handlers
• Rebus.Connection - Supervised connection processes that handle D-Bus protocol communication
• Rebus.Message - Message creation, encoding, decoding, and validation
• Rebus.Encoder - D-Bus wire format encoding with proper alignment
• Rebus.Decoder - D-Bus wire format decoding with struct boundary tracking
• Rebus.SignalHandler - Event-based signal distribution to registered handlers

Connection Types

Rebus supports connecting to different types of D-Bus endpoints:

• TCP/IP connections - %{family: :inet, addr: {{ip_tuple}, port}}
• Unix domain sockets - %{family: :local, path: "/path/to/socket"}

Message Types

Rebus supports all D-Bus message types:

• :method_call - Method invocations
• :method_return - Method replies with returned data
• :error - Error responses
• :signal - Signal emissions

D-Bus Compliance

Rebus implements the D-Bus specification including:

• Proper 8-byte struct alignment in arrays
• Header field encoding at correct positions
• Message size calculations with alignment padding
• Array boundary tracking for consecutive arrays
• Position-aware encoding and decoding

Testing

Rebus includes comprehensive testing infrastructure:

• 200+ test cases covering encoding, decoding, message handling, and edge cases
• Test server infrastructure for integration testing
• Code coverage reporting with test utilities excluded from metrics
• Property-based testing for robust validation

Installation

Add rebus to your list of dependencies in mix.exs:

def deps do
  [
    {:rebus, "~> 0.1.0"}
  ]
end

Documentation

Documentation can be generated with ExDoc:

mix docs

The generated documentation includes comprehensive API references, examples, and implementation details.

License

This project is licensed under the MIT License.

Contributing

1. Fork the repository
2. Create your feature branch (git checkout -b feature/my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin feature/my-new-feature)
5. Create a new Pull Request

Make sure to run the test suite before submitting:

mix test
mix test --cover  # With coverage reporting