File size: 2,114 Bytes
736324b | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 | """Verify and reconstruct content-addressed MemRSI experimental artifacts (stdlib only)."""
import argparse,gzip,hashlib,json,tarfile
from pathlib import Path,PurePosixPath
def digest(path):
h=hashlib.sha256()
with path.open('rb') as f:
for chunk in iter(lambda:f.read(4*1024*1024),b''):h.update(chunk)
return h.hexdigest()
def main():
p=argparse.ArgumentParser(description=__doc__);p.add_argument('--data-dir',type=Path,required=True);p.add_argument('--output',type=Path,required=True);p.add_argument('--text-only',action='store_true');a=p.parse_args()
checks=json.loads((a.data_dir/'DATA-SHA256.json').read_text());need={'file-index.jsonl.gz','text-objects.tar.gz'}
if not a.text_only:need.add('media-objects.tar.gz')
for n in need:
assert digest(a.data_dir/n)==checks[n]['sha256'],f'Archive checksum mismatch: {n}'
with gzip.open(a.data_dir/'file-index.jsonl.gz','rt') as f:rows=[json.loads(l) for l in f]
by_archive={}
for r in rows:
if a.text_only and r['disposition']!='text':continue
by_archive.setdefault(r['archive'],{}).setdefault(r['object'],[]).append(r)
a.output.mkdir(parents=True,exist_ok=True);base=a.output.resolve();count=0
for n,objects in by_archive.items():
with tarfile.open(a.data_dir/n,'r|gz') as archive:
for member in archive:
if member.name not in objects:continue
assert member.isfile(),'Unexpected non-file archive object'
data=archive.extractfile(member).read();sha=hashlib.sha256(data).hexdigest()
for r in objects.pop(member.name):
assert sha==r['public_sha256'] and len(data)==r['public_bytes'],r['path']
rel=PurePosixPath(r['path']);assert not rel.is_absolute() and '..' not in rel.parts
dest=base/str(rel);assert dest.resolve().is_relative_to(base),'Path escapes destination'
dest.parent.mkdir(parents=True,exist_ok=True)
if dest.exists():assert not dest.is_symlink() and digest(dest)==sha,f'Refusing overwrite: {dest}'
else:dest.write_bytes(data)
count+=1
assert not objects,f'Missing objects: {len(objects)}'
print(f'Verified and restored {count} files to {base}')
if __name__=='__main__':main()
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