| """Standard-library-only metadata reader for LoopVL weight snapshots. |
| |
| No code is imported from the snapshot. Version 2 stores all data files at its |
| root; version 1 retains its original nested image-processor JSON for backwards |
| compatibility. Both versions use the same code distributed in this runtime. |
| """ |
| from __future__ import annotations |
|
|
| import json |
| from pathlib import Path |
|
|
|
|
| COMPONENT_DTYPES = { |
| "vision": "bfloat16", |
| "language": "bfloat16", |
| "projector": "float32", |
| "visual_gate": "float32", |
| "visual_anchor": "float32", |
| } |
|
|
| FLAT_DATA_FILES = ( |
| "model.safetensors", |
| "config.json", |
| "generation_config.json", |
| "preprocessor_config.json", |
| "tokenizer.json", |
| "tokenizer_config.json", |
| ) |
|
|
| PROCESSOR_FIELDS = ( |
| "do_convert_rgb", "do_normalize", "do_rescale", "do_resize", |
| "image_mean", "image_std", "max_tokens", "min_tokens", "patch_size", |
| "resample", "rescale_factor", |
| ) |
|
|
|
|
| def read_checkpoint_metadata(model_dir: str | Path) -> dict: |
| """Read and validate format metadata without torch, transformers or imports.""" |
| root = Path(model_dir).expanduser().resolve() |
| raw = json.loads((root / "config.json").read_text(encoding="utf-8")) |
| if raw.get("model_type") != "loopvl" or raw.get("format_version") not in (1, 2): |
| raise ValueError("Expected LoopVL single-file checkpoint format_version 1 or 2") |
| if raw.get("component_dtypes") != COMPONENT_DTYPES: |
| raise ValueError("This loader requires the original BF16 cores / FP32 adapters") |
| for field in ("loopvl_config", "text_config", "vision_config"): |
| if not isinstance(raw.get(field), dict): |
| raise ValueError(f"Checkpoint lacks embedded {field}") |
| if raw["text_config"].get("model_type") != "hrm_text": |
| raise ValueError("Expected the embedded hrm_text language configuration") |
| if raw["vision_config"].get("model_type") != "penguinvl_vision_encoder": |
| raise ValueError("Expected the embedded penguinvl_vision_encoder configuration") |
| return raw |
|
|
|
|
| def read_processor_config(model_dir: str | Path, raw: dict | None = None) -> dict: |
| """Return the original processor parameters, never a remote-code reference. |
| |
| The old root preprocessor_config.json was only a bundle description and is |
| deliberately not used for format 1. Omitting the true image mean/std would |
| silently select CLIP defaults and change pixel values. |
| """ |
| root = Path(model_dir).expanduser().resolve() |
| if raw is None: |
| raw = read_checkpoint_metadata(root) |
| version = raw.get("format_version") |
| if version == 1: |
| path = root / "penguin_encoder" / "preprocessor_config.json" |
| elif version == 2: |
| path = root / "preprocessor_config.json" |
| else: |
| raise ValueError("Unsupported processor metadata format") |
| values = json.loads(path.read_text(encoding="utf-8")) |
| missing = sorted(set(PROCESSOR_FIELDS) - set(values)) |
| if missing: |
| raise ValueError(f"Missing actual Penguin image-processor parameters: {missing}") |
| kind = values.get("image_processor_type", "PenguinVLImageProcessor") |
| if kind != "PenguinVLImageProcessor": |
| raise ValueError(f"Unexpected image_processor_type: {kind!r}") |
| |
| |
| values.pop("auto_map", None) |
| return values |
|
|
