| """Dispatch AC2 numerical work to the optional C++ runtime.""" |
|
|
| from __future__ import annotations |
|
|
| import os |
|
|
| __all__ = ["native", "have_native", "require_native", "resolve_backend", "native_kernel"] |
|
|
| try: |
| from . import _native as native |
| except ImportError: |
| try: |
| from actioncodec2.core.backends.actioncodec2 import _native as native |
| except ImportError: |
| try: |
| from actioncodec2_kernels import _native as native |
| except ImportError: |
| native = None |
|
|
|
|
| def have_native() -> bool: |
| """True when the compiled kernels are importable and not disabled.""" |
| return native is not None and not os.environ.get("ACTIONCODEC2_NO_NATIVE") |
|
|
|
|
| def native_kernel(name: str): |
| """Resolve an optional kernel, honoring the Python reference override.""" |
| return getattr(native, name, None) if have_native() else None |
|
|
|
|
| def require_native(): |
| """Return the native module or explain how to get one.""" |
| if not have_native(): |
| raise RuntimeError( |
| "the actioncodec2 native extension is not available; run " |
| "'python setup.py build_ext --inplace' from the repository root or " |
| "select backend='python'" |
| ) |
| return native |
|
|
|
|
| def resolve_backend(backend: str) -> str: |
| """Turn ``'auto'`` into a concrete backend name.""" |
| if backend not in {"auto", "native", "python"}: |
| raise ValueError("backend must be 'auto', 'native' or 'python'") |
| if backend == "auto": |
| return "native" if have_native() else "python" |
| if backend == "native": |
| require_native() |
| return backend |
|
|
