digest.py
python
sha256:0e9549ec7b463911bc08b7d586dc320b1ac9b1f5c943ee7e3865dcc6cb0f6f83
chore(governance): sync handover+roadmap to 84db8c8 (drift:…
Human
2 days ago
| 1 | """Footprint digest computation per §K4.7.""" |
| 2 | |
| 3 | from __future__ import annotations |
| 4 | |
| 5 | import hashlib |
| 6 | import re |
| 7 | from dataclasses import dataclass |
| 8 | |
| 9 | |
| 10 | @dataclass(frozen=True) |
| 11 | class FootprintRecord: |
| 12 | """Per-file digest record for manifest and aggregate hash.""" |
| 13 | |
| 14 | path: str |
| 15 | sha256_hex: str |
| 16 | |
| 17 | |
| 18 | def canonical_bytes(data: bytes) -> bytes: |
| 19 | """Normalize line endings to LF without altering trailing newline count.""" |
| 20 | text = data.decode("utf-8") |
| 21 | normalized = text.replace("\r\n", "\n").replace("\r", "\n") |
| 22 | return normalized.encode("utf-8") |
| 23 | |
| 24 | |
| 25 | def sha256_hex(data: bytes) -> str: |
| 26 | """Return lowercase hex sha256 of canonical bytes.""" |
| 27 | return hashlib.sha256(canonical_bytes(data)).hexdigest() |
| 28 | |
| 29 | |
| 30 | def sha256_hex_raw(data: bytes) -> str: |
| 31 | """Return lowercase hex sha256 of raw bytes (for manifest aggregate).""" |
| 32 | return hashlib.sha256(data).hexdigest() |
| 33 | |
| 34 | |
| 35 | def build_manifest_lines(records: list[FootprintRecord]) -> str: |
| 36 | """Build the sorted sha256sum-style manifest string.""" |
| 37 | sorted_records = sorted(records, key=lambda r: r.path) |
| 38 | lines = [f"{rec.sha256_hex} {rec.path}\n" for rec in sorted_records] |
| 39 | return "".join(lines) |
| 40 | |
| 41 | |
| 42 | def compute_footprint_digest(records: list[FootprintRecord]) -> str: |
| 43 | """Compute aggregate ``sha256:<hex>`` digest over sorted manifest lines.""" |
| 44 | manifest = build_manifest_lines(records) |
| 45 | digest_hex = sha256_hex_raw(manifest.encode("utf-8")) |
| 46 | return f"sha256:{digest_hex}" |
| 47 | |
| 48 | |
| 49 | def records_from_bytes(path: str, content: bytes) -> FootprintRecord: |
| 50 | """Create a per-file record from raw file bytes.""" |
| 51 | return FootprintRecord(path=path, sha256_hex=sha256_hex(content)) |
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1 commit
sha256:6abcf1fa82a7a621ccbc945f19acdba5bc0db54569599404a1452fb4a096a199
fix(ISR): default require_independent_second_reviewer to require
Human
minor
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2 days ago