Core Concepts

Purpose

Deep dive into the internal architecture and design decisions of Rcon.

Topics

• Fragment Resolution - How multi-packet responses are handled

• Thread Safety Model - Concurrent command execution

• Packet Protocol - Binary encoding details

• Byte Order - Little-endian encoding

• Buffer Management - I/O buffer strategies

• Charset Handling - Text encoding for color codes

Architecture

Rcon follows a layered architecture with clear separation of concerns:

1. High-Level API (RconClient) - User-friendly interface with logging

2. Core API (Rcon) - Thread-safe protocol implementation

3. I/O Layer (PacketReader/PacketWriter) - Socket operations

4. Codec Layer (PacketCodec) - Binary encoding/decoding

5. Domain Model (Packet) - Immutable packet representation

Each layer has a single responsibility and can be used independently if needed.

Design Principles

• Zero Dependencies - Pure Java standard library

• Immutability - Packet objects are immutable

• Thread Safety - Safe concurrent access via synchronized methods

• Separation of Concerns - Clear layer boundaries

• Configurability - Pluggable strategies and options

Performance Characteristics

• Minimal Allocation - Buffers are reused via compact()

• Lock-Free Counter - AtomicInteger for request IDs

• Efficient Encoding - Direct buffer manipulation

• Smart Fragment Resolution - Default strategy minimizes round-trips

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Table of contents

• Fragment Resolution
• Thread Safety Model
• Packet Protocol
• Byte Order
• Charset Handling
• Buffer Management