| |
| """Inspect a source asset, or explicitly download a commit-pinned GitHub asset.""" |
| import argparse |
| import hashlib |
| import json |
| from pathlib import Path |
| import urllib.parse |
| import urllib.request |
|
|
|
|
| def github_raw_url(url): |
| parsed = urllib.parse.urlsplit(url) |
| parts = parsed.path.split('/') |
| if parsed.hostname != 'github.com' or len(parts) < 6 or parts[3] != 'blob': |
| raise ValueError('Expected a GitHub blob URL') |
| owner, repo, revision = parts[1], parts[2], parts[4] |
| if len(revision) != 40 or any(c not in '0123456789abcdef' for c in revision.lower()): |
| raise ValueError('Source URL is not pinned to a full commit') |
| raw_path = '/'.join([owner, repo, revision] + parts[5:]) |
| return 'https://raw.githubusercontent.com/' + urllib.parse.quote(urllib.parse.unquote(raw_path), safe='/') |
|
|
|
|
| def main(): |
| parser = argparse.ArgumentParser(description=__doc__) |
| parser.add_argument('manifest', type=Path) |
| parser.add_argument('sample_id') |
| parser.add_argument('--download', action='store_true') |
| parser.add_argument('--output', type=Path) |
| args = parser.parse_args() |
| record = next((r for r in map(json.loads, args.manifest.open()) if r['sample_id'] == args.sample_id), None) |
| if record is None: |
| parser.error('Sample ID not found') |
| info = {k: record[k] for k in ['sample_id', 'source_asset_id', 'source_url', 'source_file_type', |
| 'source_sha256', 'historical_license', 'observed_license_url', 'provenance_flags']} |
| if record['source_group'] == 'github': |
| info['download_url'] = github_raw_url(record['source_url']) |
| else: |
| info['download_method'] = 'Use the original Sketchfab page and its official download flow.' |
| print(json.dumps(info, indent=2, ensure_ascii=False)) |
| if not args.download: |
| return |
| if record['source_group'] != 'github': |
| parser.error('Automatic Sketchfab downloads are not implemented; use the official source flow.') |
| if args.output is None: |
| parser.error('--download requires --output') |
| if args.output.exists(): |
| parser.error('Output already exists; select a new path') |
| partial = args.output.with_name(args.output.name + '.partial') |
| digest = hashlib.sha256() |
| created = False |
| try: |
| with partial.open('xb') as out: |
| created = True |
| with urllib.request.urlopen(info['download_url'], timeout=60) as response: |
| for chunk in iter(lambda: response.read(1024 * 1024), b''): |
| out.write(chunk) |
| digest.update(chunk) |
| if digest.hexdigest() != record['source_sha256']: |
| raise ValueError('Source SHA-256 mismatch; upstream content or a Git LFS pointer may differ') |
| partial.rename(args.output) |
| except Exception: |
| if created and partial.exists(): |
| partial.unlink() |
| raise |
| print('Verified source asset saved to ' + str(args.output)) |
|
|
|
|
| if __name__ == '__main__': |
| main() |
|
|
