| """Reassemble uploaded byte shards into the exact original NPY file."""
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| import argparse,hashlib,json,shutil
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| from pathlib import Path
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|
|
| def sha(path):
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| h=hashlib.sha256()
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| with path.open('rb') as stream:
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| while data:=stream.read(8*1024**2): h.update(data)
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| return h.hexdigest()
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|
|
| def main():
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| parser=argparse.ArgumentParser(description=__doc__)
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| parser.add_argument('--root',type=Path,default=Path(__file__).resolve().parent)
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| args=parser.parse_args();root=args.root.resolve()
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| manifest=json.loads((root/'asset_manifest.json').read_text(encoding='utf-8'))
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| for item in manifest.get('reassemble',[]):
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| target=(root/item['path']).resolve()
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| if not target.is_relative_to(root):raise ValueError('Path escapes asset root')
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| target.parent.mkdir(parents=True,exist_ok=True)
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| if target.exists():
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| if target.stat().st_size!=item['bytes'] or sha(target)!=item['sha256']:
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| raise ValueError('Existing output differs; refusing overwrite')
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| print('Already verified:',item['path']);continue
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| if shutil.disk_usage(target.parent).free<item['bytes']:
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| raise RuntimeError('Insufficient space for the restored NPY; shards are retained')
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| temp=target.with_name(target.name+'.restoring')
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| digest=hashlib.sha256();written=0
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| try:
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| with temp.open('xb') as output:
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| for part in item['parts']:
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| if part['byte_offset']!=written:raise ValueError('Non-contiguous shards')
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| source=(root/part['path']).resolve()
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| if not source.is_relative_to(root) or source.stat().st_size!=part['bytes']:
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| raise ValueError('Missing or invalid shard')
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| part_hash=hashlib.sha256()
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| with source.open('rb') as stream:
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| while data:=stream.read(8*1024**2):
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| output.write(data);part_hash.update(data);digest.update(data);written+=len(data)
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| if part_hash.hexdigest()!=part['sha256']:raise ValueError('Shard checksum mismatch')
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| if written!=item['bytes'] or digest.hexdigest()!=item['sha256']:
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| raise ValueError('Restored NPY checksum mismatch')
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| temp.rename(target)
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| except Exception:
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|
|
| raise
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| print('Restored and verified:',item['path'])
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|
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| if __name__=='__main__':main()
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|
|
