feat: resolve files by crc32, sha256 and case-folded names

This commit is contained in:
Abdessamad Derraz committed 2026-08-06 16:41:47 +02:00
1 parent 6cbcb609af
commit c4bef1010a
1 file changed
+49 -6
+49 -6
View File
@@ -98,6 +98,21 @@ def md5sum(source: str | Path | object) -> str:
_md5_composite_cache: dict[str, str] = {}
_casefold_index_cache: dict[int, dict[str, list[str]]] = {}
def _casefold_name_index(by_name: dict) -> dict[str, list[str]]:
"""Build (and cache) a casefolded view of the by_name index."""
key = id(by_name)
cached = _casefold_index_cache.get(key)
if cached is not None:
return cached
folded: dict[str, list[str]] = {}
for name, sha1s in by_name.items():
folded.setdefault(name.casefold(), []).extend(sha1s)
_casefold_index_cache[key] = folded
return folded
def md5_composite(filepath: str | Path) -> str:
"""Compute composite MD5 of a ZIP - matches Recalbox's Zip::Md5Composite().
@@ -386,7 +401,7 @@ def resolve_local_file(
exact, zip_exact, hash_mismatch, not_found.
"""
sha1 = file_entry.get("sha1")
md5_raw = file_entry.get("md5", "")
md5_raw = str(file_entry.get("md5", "") or "")
name = file_entry.get("name", "")
zipped_file = file_entry.get("zipped_file")
aliases = file_entry.get("aliases", [])
@@ -423,11 +438,13 @@ def resolve_local_file(
if os.path.exists(path):
return path, "exact"
# 1. SHA1 exact match
if sha1 and sha1 in files_db:
path = files_db[sha1]["path"]
if os.path.exists(path):
return path, "exact"
# 1. SHA1 exact match (accept list-valued sha1 from profiles)
sha1_candidates = sha1 if isinstance(sha1, list) else [sha1] if sha1 else []
for cand in sha1_candidates:
if isinstance(cand, str) and cand in files_db:
path = files_db[cand]["path"]
if os.path.exists(path):
return path, "exact"
# 1b. SHA256 exact match (profiles hashed from sources that publish
# sha256, e.g. MesenCE). A full sha256 is a strong identifier.
@@ -443,6 +460,20 @@ def resolve_local_file(
if os.path.exists(path):
return path, "exact"
# 1c. CRC32 + size exact match, only when no stronger hash is declared
# (crc-only profiles: FBNeo, Clock Signal). CRC32 alone is weak, so the
# declared size must confirm the match.
crc_raw = str(file_entry.get("crc32", "") or "").strip().lower()
declared_size = file_entry.get("size")
if crc_raw and declared_size and not zipped_file and not md5_raw:
by_crc32 = db.get("indexes", {}).get("by_crc32", {})
match = by_crc32.get(crc_raw)
if match and match in files_db:
entry = files_db[match]
path = entry["path"]
if entry.get("size") == declared_size and os.path.exists(path):
return path, "exact"
# 2. MD5 direct lookup (skip for zipped_file: md5 is inner ROM, not container)
# Guard: only accept if the found file's name matches the requested name
# (or is a .variants/ derivative). Prevents cross-contamination when an
@@ -483,6 +514,18 @@ def resolve_local_file(
path = files_db[match_sha1]["path"]
if os.path.exists(path) and path not in candidates:
candidates.append(path)
if not candidates:
# Case-insensitive fallback: upstream platforms disagree on
# casing (VEC_MineStorm.vec vs VEC_Minestorm.vec). Safe by
# invariant: dedup keeps a single casing per content, so a
# casefold match cannot pick a different file.
folded = _casefold_name_index(by_name)
for try_name in names_to_try:
for match_sha1 in folded.get(try_name.casefold(), []):
if match_sha1 in files_db:
path = files_db[match_sha1]["path"]
if os.path.exists(path) and path not in candidates:
candidates.append(path)
if candidates:
if zipped_file:
candidates = [p for p in candidates if ".zip" in os.path.basename(p)]