| """Load an exported model for inference.""" |
|
|
| import json |
| from pathlib import Path |
|
|
| from .checkpoint import load_checkpoint |
| from .model import PayaModel |
| from .provenance import RUNTIME_CONTRACT, contained_file, sha256 |
| from .vendor import signal |
|
|
| __all__ = ["load_model"] |
|
|
|
|
| def load_model(directory, device="cpu"): |
| root = Path(directory).resolve() |
| manifest = json.loads((root/"manifest.json").read_text(encoding="utf-8")) |
| if manifest.get("contract") != RUNTIME_CONTRACT: |
| raise ValueError("Unsupported model architecture") |
| for name, expected in manifest["files"].items(): |
| if sha256(contained_file(root, name)) != expected: |
| raise ValueError(f"Model file checksum changed: {name}") |
| config = json.loads((root/"config.json").read_text(encoding="utf-8")) |
| assets = {name: root/name for name in (signal.ASSET_KEY, "text")} |
| model = PayaModel.from_assets(assets, config["preparation"], config["head"], device) |
| if manifest["identity"] != model.identity(): |
| raise ValueError("Model identities differ") |
| load_checkpoint(root/"decision.pt", model) |
| return model |
|
|
