| """Read one sample from a shard with nothing but the standard library, safetensors and zstd. |
| |
| python examples/read_one_sample.py data/validation/validation-00000-of-00001.tar |
| """ |
| import io |
| import json |
| import sys |
| import tarfile |
|
|
| import zstandard |
| from safetensors.numpy import load as st_load |
|
|
| COMPRESSED = {"mesh.safetensors", "queries.safetensors", "visibility.safetensors", |
| "meta.json"} |
|
|
|
|
| def members_of_first_sample(tar_path): |
| """The tar is written so a sample's members are always adjacent.""" |
| with tarfile.open(tar_path, "r:") as tf: |
| key, out = None, {} |
| for m in tf: |
| if not m.isfile(): |
| continue |
| k = m.name.rsplit("/", 1)[-1].split(".", 1)[0] |
| if key is None: |
| key = k |
| if k != key: |
| break |
| name = m.name.rsplit("/", 1)[-1][len(k) + 1:] |
| out[name] = tf.extractfile(m).read() |
| return key, out |
|
|
|
|
| def decode(name, blob): |
| if name.endswith(".zst"): |
| blob, name = zstandard.ZstdDecompressor().decompress(blob), name[:-4] |
| if name == "meta.json": |
| return json.loads(blob) |
| if name.endswith(".safetensors"): |
| return st_load(blob) |
| return blob |
|
|
|
|
| if __name__ == "__main__": |
| uid, raw = members_of_first_sample(sys.argv[1]) |
| payload = {} |
| for name, blob in raw.items(): |
| clean = name[:-4] if name.endswith(".zst") else name |
| payload[clean] = decode(name, blob) |
|
|
| print(f"uid {uid}") |
| mesh, q = payload["mesh.safetensors"], payload["queries.safetensors"] |
| print(f" faces {mesh['faces'].shape[0]:,} vertices {mesh['vertices'].shape[0]:,}") |
| for fam in ("xatlas", "smart_uv", "partial"): |
| valid = (q[f"{fam}_valid_mask"] > 0).mean() |
| print(f" {fam:9s} texture {q[f'{fam}_gt_texture'].shape} " |
| f"valid {valid:.1%}") |
| vis = payload["visibility.safetensors"]["xatlas_vis"] |
| print(f" visibility {vis.shape} visible texels per view " |
| f"{[int((vis[i] == 2).sum()) for i in range(vis.shape[0])]}") |
| views = [k for k in payload if k.endswith(".png")] |
| print(f" views {sorted(views)}") |
| meta = payload["meta.json"] |
| print(f" release {meta.get('release_version')} schema {meta.get('schema_version')}") |
|
|
