jgrusewski 8a31d3b99b cleanup(borrow): fix CudaSlice<i32>→u32 aliasing UB in episode_ids — [BORROW-001]
gpu_replay_buffer.rs had three sites that cast `&CudaSlice<i32>` to
`&CudaSlice<u32>` via raw-pointer transmutes to satisfy kernel
signatures (gather_u32, scatter_insert_u32). This changes the element
type of a `&mut` reference through `as *mut`, which is UB under Rust's
strict aliasing model even though i32 and u32 share a memory layout.

Episode-id values are always non-negative (counters of the form
`(write_cursor + j) % capacity`), so u32 is the correct storage type.
Changed:
- 3 field types: episode_ids, sample_episode_ids, insert_ep_buf
  (CudaSlice<i32> → CudaSlice<u32>)
- Allocators: a32i → a32u at 4 sites
- Vec<i32> → Vec<u32> at ep_ids_host, with `as u32` cast
- Deleted 3 raw-ptr transmute blocks (lines 491-492, 689-690)
- Public sample_episode_ids_ref() return type i32 → u32
- Deleted now-unused a32i helper (fn never called after the change)

Per BORROW learned pattern option (3): "change the declared type".
2026-04-21 00:12:08 +02:00

Foxhunt

Production HFT trading system in Rust.

Architecture

The workspace contains 32 crates organized as follows:

Core Libraries (16)

Crate Purpose
trading_engine Order processing, FIX 4.4, IB TWS, SIMD, RDTSC timing
risk VaR, Kelly, circuit breakers, kill switches, compliance
risk-data Risk data types and shared structures
trading-data Trading data types
ml DQN Rainbow, PPO, TFT, Mamba2, ensemble inference
ml-data ML data types and feature definitions
data Market data ingestion and storage
backtesting Replay engine, strategy tester
adaptive-strategy Ensemble execution, microstructure analysis
common Shared types, resilience, error handling
storage S3 and local model storage
model_loader Model serialization and loading
market-data Market data feed handlers
database PostgreSQL access layer (SQLx)
config Configuration management
tli CLI commands and tooling

Services (8)

Service Purpose
backtesting_service gRPC backtesting service
broker_gateway_service FIX routing, broker connectivity
trading_service Core trading operations
ml_training_service Model training orchestration
data_acquisition_service Market data acquisition
trading_agent_service Autonomous trading agents
api_gateway gRPC API gateway with auth
web-gateway Axum REST + WebSocket gateway

Frontend

web-dashboard/ -- React 19 + TypeScript + Vite + TradingView charts.

Building

# Check compilation (no PostgreSQL required)
SQLX_OFFLINE=true cargo check --workspace

# Run tests for a specific crate
SQLX_OFFLINE=true cargo test -p <crate> --lib

# Clippy
SQLX_OFFLINE=true cargo clippy --workspace

ML Models

Four production model architectures on Candle v0.9.1 with CUDA:

  • DQN Rainbow -- Deep Q-Network with prioritized replay, dueling heads, noisy nets
  • PPO -- Proximal Policy Optimization with GAE and LSTM policies
  • TFT -- Temporal Fusion Transformer for multi-horizon forecasting
  • Mamba2 -- State space model for sequence prediction

Each model has a standalone trainer and a UnifiedTrainable adapter for the hyperopt pipeline.

Infrastructure

  • Git: Gitea at git.fxhnt.ai (Tailscale-only), Scaleway DEV1-S
  • Observability: OpenTelemetry OTLP (env OTEL_EXPORTER_OTLP_ENDPOINT)
  • Database: PostgreSQL with SQLx offline mode for CI

License

Proprietary. All rights reserved.

Description
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Readme 849 MiB
Languages
Rust 88.2%
Cuda 7.7%
Python 1.3%
Shell 1.1%
PLpgSQL 0.8%
Other 0.8%