tegwick
29ceb77938
Assistant: codex Assistant-Model: gpt-6-astra Assistant-Session: 01a09c77-b1a9-7eb3-b501-6cb24b458c97
53 lines
1.7 KiB
Python
53 lines
1.7 KiB
Python
"""Atomic content-addressed JSON and source artifact storage."""
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import hashlib
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import json
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import os
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from pathlib import Path
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import tempfile
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def canonical(value):
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return json.dumps(value, sort_keys=True, separators=(',', ':'), ensure_ascii=False,
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allow_nan=False).encode('utf-8')
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def atomic(path, data, immutable=False):
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path = Path(path)
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path.parent.mkdir(parents=True, exist_ok=True)
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fd, name = tempfile.mkstemp(dir=path.parent, prefix='.write-')
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try:
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with os.fdopen(fd, 'wb') as stream:
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stream.write(data)
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stream.flush()
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os.fsync(stream.fileno())
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if immutable:
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try:
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os.link(name, path)
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except FileExistsError:
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if path.read_bytes() != data:
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raise ValueError(f'immutable content mismatch: {path}') from None
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else:
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os.replace(name, path)
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finally:
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Path(name).unlink(missing_ok=True)
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def put(root, kind, value):
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content = canonical(value)
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ident = hashlib.sha256(content).hexdigest()
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atomic(Path(root) / 'data' / kind / f'{ident}.json', content + b'\n', immutable=True)
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return ident
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def get(root, kind, ident):
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if len(ident) != 64 or any(c not in '0123456789abcdef' for c in ident):
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raise ValueError('invalid content ID')
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value = json.loads((Path(root) / 'data' / kind / f'{ident}.json').read_text())
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if hashlib.sha256(canonical(value)).hexdigest() != ident:
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raise ValueError(f'integrity mismatch: {kind}/{ident}')
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return value
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def all_records(root, kind):
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return [(p.stem, get(root, kind, p.stem))
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for p in sorted((Path(root) / 'data' / kind).glob('*.json'))]
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