# sglang-radix-tree

Rust tree core for the Unified Radix Cache, covering Full attention, sliding window attention, and Mamba components. It implements the tree side of the `UnifiedTreeCoreInterface` split — match/insert walks, node arena, locks, eviction walks, HiCache backup/load-back specs, and KV events — behind a PyO3 binding, while the cache orchestration stays in Python.

## Usage

Select the backend with:

```bash
SGLANG_UNIFIED_RADIX_TREE_CORE_BACKEND=rust
```

SGLang wheels bundle the production extension. A source checkout falls back to
the shared fingerprinted Rust-extension cache; it never writes a shared object
into the Python package. LibTorch and the Python headers come from the running
interpreter's PyTorch install. PyTorch 2.11 through 2.13 are accepted explicitly,
and `torch_2_13_compat.h` covers two alignment APIs removed in PyTorch 2.13.

## Development

```bash
# Build (libtorch from the installed torch package):
cd rust/sglang-radix-tree
LIBTORCH_USE_PYTORCH=1 \
  LIBTORCH_BYPASS_VERSION_CHECK=1 \
  CXXFLAGS="-include $PWD/torch_2_13_compat.h" \
  cargo build --release --locked --features python-extension

# Native tests do not enable pyo3's extension-module feature:
TORCH_ROOT=$(python3 -c 'import pathlib, torch; print(pathlib.Path(torch.__file__).parent)')
LIBTORCH_USE_PYTORCH=1 LIBTORCH_BYPASS_VERSION_CHECK=1 \
  CXXFLAGS="-include $PWD/torch_2_13_compat.h" \
  LD_LIBRARY_PATH="$TORCH_ROOT/lib${LD_LIBRARY_PATH:+:$LD_LIBRARY_PATH}" \
  cargo test --locked
```

The `inspection` Cargo feature adds white-box methods for the shared Python/Rust
cache suite. Production wheels do not enable it.

Unit tests live in `src/tests/`, mirroring the source layout one file per module (wired via `#[cfg(test)] #[path = ...]`), so implementation files stay free of inline test blocks.

Supported component sets are `[Full]`, `[Full, SWA]`, `[Full, Mamba]`, and `[Full, SWA, Mamba]`.