perf(assets): reuse source snapshot digests during lock verification

edge0-infer/tools/assets/asset_common.py

@@ -33,12 +33,13 @@ def snapshot(root: Path) -> dict[str, str]:
     return {str(p.relative_to(root)): sha256(p) for p in sorted(root.rglob('*')) if p.is_file()}
 
 
-def verify_source(source: Path, lock: dict, names=None) -> None:
+def verify_source(source: Path, lock: dict, names=None, *, digests: dict[str, str] | None = None) -> None:
     for name in names if names is not None else lock['files']:
         path = source / name
         if not path.is_file():
             raise ValueError(f'missing source file: {name}')
-        if sha256(path) != lock['files'][name]:
+        digest = sha256(path) if digests is None else digests.get(name)
+        if digest != lock['files'][name]:
             raise ValueError(f'source digest mismatch: {name}')
 
 

edge0-infer/tools/assets/edge0_35b/make_assets.py

@@ -53,8 +53,8 @@ def make_assets(source: Path, out: Path, lock: dict | None = None, converter: Pa
     if partial.exists() or partial.is_symlink():
         raise ValueError(f'an earlier run left {partial}; delete it and rerun')
     lock = lock if lock is not None else read_json(Path(__file__).with_name('source.lock.json'))
-    verify_source(source, lock)
     before = snapshot(source)
+    verify_source(source, lock, digests=before)
     partial.mkdir(parents=True, exist_ok=False)
     try:
         _convert(source, out, partial, lock, converter, before)

edge0-infer/tools/assets/tests/test_make_assets.py

@@ -167,3 +167,26 @@ def test_repository_converter_is_recorded_relative(tmp_path):
     partial = tmp_path / 'out.partial'
     assert maker.recorded_path(maker.CONVERTER, partial) == 'tools/assets/edge0_35b/edge0_convert/convert_mlx_to_gguf.py'
     assert maker.recorded_path(partial / 'staging/edge0-35b', partial) == '<partial>/staging/edge0-35b'
+
+
+def test_source_snapshot_is_reused_for_lock_verification(setup, monkeypatch):
+    import asset_common
+    from collections import Counter
+
+    source, out, lock, converter, _ = setup
+    original = asset_common.sha256
+    reads = Counter()
+
+    def counted(path):
+        path = Path(path)
+        if path.parent == source:
+            reads[path.name] += 1
+        return original(path)
+
+    monkeypatch.setattr(asset_common, 'sha256', counted)
+    with pytest.raises(maker.MakeError):
+        maker.make_assets(source, out, lock, converter)
+    # One digest supplies both the initial snapshot and lock verification;
+    # the finally block independently verifies that the converter changed nothing.
+    assert dict(reads) == {name: 2 for name in lock['files']}
+    assert not out.exists()