Skip to content

Codebase Architecture

The Shardian workspace is structured as a monorepo containing the symbolic training engine, C++ and Fortran solver modules, and the licensing infrastructure.

1. Directory Structure

shardian-workspace/
├── applications/
│   ├── openfoam_cfd/       # Shardian Aero (OpenFOAM C++ library source)
│   │   ├── Make/           # Compilation directives (files, options)
│   │   └── AdvancedZonalModel/
│   ├── wrf/                # Shardian Atmos (WRF Fortran boundary layer modules)
│   │   └── phys/           # module_bl_eml_sr.F source files
│   ├── license-server/     # Go/SQLite authentication server & key generator CLI
│   └── shardian-web/       # Main public website and installer scripts
├── eml-sr-core/            # Symbolic regression JAX-based training framework
├── scripts/                # Build, deployment, and weight export utilities
└── datasets/               # High-fidelity DNS training and validation profiles

2. Component Design & Clean Boundaries

To maintain high performance and avoid runtime dependency overhead (e.g., calling Python interpreters or JAX from C++), the codebase enforces a strict separation between Offline Training and Online Simulation.

graph LR
    subgraph "Offline Phase (Python)"
        A[eml-sr-core] -->|Symbolic Fit| B(Math Expressions)
    end
    subgraph "Online Phase (C++ & Fortran)"
        C[export scripts] -->|Code Generation| D(Hardcoded Source)
        D --> E[wmake libso / compile WRF]
    end
    B --> C

A. Shardian Aero (applications/openfoam_cfd)

  • Technology: C++ (OpenFOAM Foundation standard).
  • Compilation: Built using wmake libso, which outputs the dynamic library libShardianAero.so to the user's $FOAM_USER_LIBBIN path.
  • Coupling: Extends RASModel in OpenFOAM. It calculates \(\nu_t\) using hardcoded inline algebraic equations representing the symbolic models.

B. Shardian Atmos (applications/wrf)

  • Technology: Modern Fortran.
  • Integration: Injects module_bl_eml_sr.F into the WRF compilation pipeline. It hooks into the WRF physics driver (phys/module_pbl_driver.F) at flag bl_pbl_physics = 99.
  • Zero-Dependency: The JAX-discovered symbolic boundary layer formulas are written directly as nested Fortran arithmetic blocks.

C. License Server (applications/license-server)

  • Technology: Go / SQLite.
  • Database: A single lightweight database (licenses.db) storing issued API keys, active scopes, expiration dates, and activation statuses.
  • Endpoints: Exposes HTTPS endpoints (/v1/verify for solvers, /v1/admin for key management).
  • Authentication: Evaluated in the first time-step of a simulation using a lightweight HTTPS thread, caching the result to avoid repeating checks.