Module simulation 

Deterministic simulation testing framework. Deterministic simulation testing framework for Freenet.

This module provides infrastructure for running reproducible network simulations with deterministic time advancement, seeded randomness, and fault injection.

Architecture

The simulation framework is built around several key components:

• TimeSource: Abstraction over time operations (real vs virtual)
• VirtualTime: Deterministic time that only advances when explicitly stepped
• SimulationRng: Seeded RNG for all random decisions during simulation
• FaultConfig: Configuration for fault injection (drops, partitions, latency)

SimNetwork (Production-Ready)

Location: testing_impl.rs

What it does:

• Runs actual Freenet node code as async tasks
• Uses InMemoryTransport for fast message passing
• Supports fault injection via FaultConfig
• Provides convergence checking and operation tracking
• Uses Turmoil for deterministic task scheduling

Use for: Integration testing, end-to-end tests, fdev test mode

Usage Example

use freenet::dev_tool::SimNetwork;
use freenet::simulation::FaultConfig;

// Create network with deterministic seed
let mut sim = SimNetwork::new("test", 1, 3, 10, 7, 10, 5, 0x1234).await;

// Enable fault injection
sim.with_fault_injection(
    FaultConfig::builder()
        .message_loss_rate(0.05)
        .latency_range(Duration::from_millis(10)..Duration::from_millis(50))
        .build()
);

// Run operations and check results
let handles = sim.start_with_rand_gen::<SmallRng>(0x1234, 10, 5).await;
sim.await_convergence(Duration::from_secs(30), Duration::from_millis(500), 1).await?;

// Verify operation success
let summary = sim.get_operation_summary().await;
assert!(summary.overall_success_rate() >= 0.9);

Structs

FaultConfig

Configuration for fault injection during simulation.

FaultConfigBuilder

Builder for creating FaultConfig with fluent API.

Partition

A network partition between sets of peers.

RealTime

Real-time implementation that delegates to tokio.

SimulationRng

A thread-safe, seeded random number generator for simulation.

TimeSourceInterval

An interval timer that works with any TimeSource.

VirtualTime

Virtual time implementation for deterministic simulation.

Wakeup

A pending wakeup in the virtual time system.

WakeupId

Unique identifier for a wakeup registration.

Traits

TimeSource

Abstraction over time operations supporting both real and virtual time.