ROHCスター

Rohcstar is a modern and memory-safe Rust implementation of the Robust Header Compression (ROHC) framework.

Warning

This ROHC implementation is in early development phase. The API is unstable, features are incomplete, and breaking changes should be expected.

Overview

Rohcstar implements RFC 3095 to compress IP/UDP/RTP headers from 40-60 bytes down to 1-3 bytes. Built for real-world use with focus on correctness, performance, and maintainability.

Current Status:

• Profile 0x0001 (RTP/UDP/IP) Unidirectional Mode: Complete
• All packet types implemented (IR, IR-DYN, UO-0, UO-1 variants)
• Robust state machines with proper error recovery
• Comprehensive test coverage

Coming Next:

• Additional profiles (UDP/IP, ESP/IP)
• Bidirectional modes (O-mode, R-mode)
• Performance optimizations

Usage

use rohcstar::{RohcEngine, RohcProfile};
use rohcstar::profiles::profile1::{Profile1Handler, RtpUdpIpv4Headers};
use std::time::Duration;

let mut engine = RohcEngine::new(16, Duration::from_secs(300));
engine.register_profile_handler(Box::new(Profile1Handler::new()))?;

// Compress
let headers = RtpUdpIpv4Headers {
    ip_src: "192.168.1.10".parse()?,
    ip_dst: "192.168.1.20".parse()?,
    udp_src_port: 5004,
    udp_dst_port: 5006,
    rtp_ssrc: 0x12345678.into(),
    rtp_sequence_number: 100.into(),
    rtp_timestamp: 8000.into(),
    ..Default::default()
};

let mut buffer = [0u8; 128];
let compressed_len = engine.compress(
    0.into(),
    Some(RohcProfile::RtpUdpIp),
    &headers.into(),
    &mut buffer,
)?;

// Decompress
let decompressed = engine.decompress(&buffer[..compressed_len])?;

Performance

Rohcstar includes a benchmark suite to measure and monitor performance of critical ROHC operations:

• Packet Parsing: Raw parsing performance of RTP/UDP/IPv4 headers (>3 GiB/s)
• LSB Operations: Core W-LSB encoding/decoding algorithms (<5 ns per operation)
• CRC Operations: CRC-3 and CRC-8 calculations for packet validation (>800 MiB/s)
• Compression Pipeline: Full compression workflow including packet type selection
• Decompression Pipeline: Full decompression with context reconstruction
• Full Roundtrip: End-to-end compression and decompression cycles (<600 ns)
• Context Management: Context creation, lookup, and management overhead

Running Benchmarks

# Quick benchmark run
./scripts/run_benchmarks.sh --quick

# Run specific benchmark group
./scripts/run_benchmarks.sh packet_parsing

# Full benchmarks with HTML reports
./scripts/run_benchmarks.sh --full --html

# Direct cargo usage
cd rohcstar && cargo bench --bench rohc_benchmarks

See BENCHMARKS.md for detailed performance analysis, optimization guidance, benchmark descriptions, and CI/CD integration.

Development

Building

cargo build --release
cargo test
cargo bench

Style

See STYLE.md and NAMING_CONVENTIONS.md.

Key points:

• Correctness over performance
• Measure everything
• No premature abstractions
• Comprehensive tests required

Contributing

1. Follow style guide strictly
2. Add tests for new features
3. Benchmark performance changes
4. Update documentation

Documentation

• Design - Architecture and implementation
• Style Guide - Code conventions
• ROHC Bible - RFC reference
• Benchmarks - Performance analysis

License

Rohcstar is licensed under the MIT License.