Files
libretro/tests/test_agnostic_scan.py
T
Abdessamad Derraz b11c8b0638 fix: keep the agnostic scan inside its own tree
A filename-agnostic core accepts any name for its BIOS, so the builder
scans the directory holding the candidates. It picked that directory
from a first-hit lookup by name, the one piece of evidence that lands
in another emulator's tree: five files answer to GameIndex.yaml and one
belongs to an Android package, rom1.bin is a PS2 ROM and a Roland
SC-55 ROM. One wrong match became every file beside it, flattened into
the BIOS root of platforms that do not run that emulator: 45 files in
the Recalbox pack, 170 in the RetroArch one.

Four things decide it now. A destination and the repo layout meet on a
tail, so the path index is tried from the longest tail down and never
to the bare filename; that alone corrects seven files, among them the
Japanese GameCube slot, which held the US dump. A seed has to declare
the shape it is looking for, since no shape means the whole directory.
An ambiguous name needs the profile's other files to agree before the
scan walks anywhere. What the scan emits carries the SHA-1 it selected,
so packing never resolves it by name again.
2026-08-12 07:23:23 +02:00

256 lines
9.1 KiB
Python

#!/usr/bin/env python3
"""The filename-agnostic scan and the tree it is allowed to walk.
Some emulators accept any filename for their BIOS, so the builder scans the
directory holding the candidates and packs what matches. The directory came
from a first-hit lookup by name, which is the one piece of evidence that can
land in another emulator's tree: five files in the collection answer to
GameIndex.yaml and one of them belongs to an Android package. The scan then
turned that single wrong match into every file beside it, flattened into the
BIOS root of platforms that do not run that emulator.
"""
from __future__ import annotations
import hashlib
import sys
import tempfile
import unittest
from pathlib import Path
REPO_ROOT = Path(__file__).resolve().parent.parent
sys.path.insert(0, str(REPO_ROOT / "scripts"))
import common # noqa: E402
import generate_pack as builder # noqa: E402
SIZE = 1024
def _blob(root: Path, relative: str, filler: bytes) -> tuple[str, dict]:
path = root / relative
path.parent.mkdir(parents=True, exist_ok=True)
payload = (filler * SIZE)[:SIZE]
path.write_bytes(payload)
sha1 = hashlib.sha1(payload).hexdigest()
return sha1, {
"path": str(path),
"name": path.name,
"size": SIZE,
"sha1": sha1,
"md5": hashlib.md5(payload).hexdigest(),
"sha256": hashlib.sha256(payload).hexdigest(),
"crc32": "00000000",
}
class AgnosticScanStaysInItsTree(unittest.TestCase):
def setUp(self):
self._tmp = tempfile.TemporaryDirectory()
self.root = Path(self._tmp.name)
(self.root / "emulators").mkdir()
files: dict[str, dict] = {}
by_name: dict[str, list[str]] = {}
def add(relative: str, filler: bytes):
sha1, record = _blob(self.root, relative, filler)
files[sha1] = record
by_name.setdefault(record["name"], []).append(sha1)
# The system's own BIOS directory: three interchangeable dumps.
add("bios/SystemA/boot.bin", b"A")
add("bios/SystemA/boot-alt.bin", b"B")
add("bios/SystemA/boot-jp.bin", b"C")
# Another emulator's asset tree, holding a file of the same name and
# a crowd of same-sized neighbours the scan must not claim.
add("bios/Other/someapp/shared.bin", b"D")
for n in range(20):
add(f"bios/Other/someapp/icons/flag{n:02d}.bin", bytes([n or 1]))
# The same filename on both sides, which is the whole difficulty:
# rom1.bin is a PlayStation 2 ROM and a Roland SC-55 ROM. The foreign
# copy is indexed first, so a lookup by name reaches it first.
add("bios/SystemA/shared.bin", b"E")
self.db = {
"files": files,
"indexes": {
"by_name": by_name,
"by_md5": {r["md5"]: s for s, r in files.items()},
"by_sha256": {},
"by_crc32": {},
"by_path_suffix": {},
},
}
self.config = {
"platform": "Demo",
"verification_mode": "existence",
"cores": ["demo"],
"base_destination": "",
"systems": {},
}
common._emulator_profiles_cache.clear()
def tearDown(self):
common._emulator_profiles_cache.clear()
self._tmp.cleanup()
def _write_profile(self, body: str):
(self.root / "emulators" / "demo.yml").write_text(body)
return common.load_emulator_profiles(str(self.root / "emulators"))
def _scan(self, profiles):
extras = builder._collect_emulator_extras(
self.config, str(self.root / "emulators"), self.db, set(), "",
profiles,
)
return [e for e in extras if e.get("agnostic_scan")]
def test_it_collects_the_interchangeable_dumps(self):
profiles = self._write_profile(
"emulator: demo\n"
"type: libretro\n"
"display_name: Demo\n"
"bios_mode: agnostic\n"
"systems: [demo-system]\n"
"cores: [demo]\n"
"files:\n"
" - name: boot.bin\n"
" system: demo-system\n"
" size: 1024\n"
" - name: boot-alt.bin\n"
" system: demo-system\n"
" size: 1024\n"
)
found = {e["name"] for e in self._scan(profiles)}
self.assertEqual(
found, {"boot.bin", "boot-alt.bin", "boot-jp.bin", "shared.bin"}
)
def test_one_colliding_filename_does_not_import_a_foreign_tree(self):
"""shared.bin resolves into another emulator's directory by name."""
profiles = self._write_profile(
"emulator: demo\n"
"type: libretro\n"
"display_name: Demo\n"
"bios_mode: agnostic\n"
"systems: [demo-system]\n"
"cores: [demo]\n"
"files:\n"
" - name: boot.bin\n"
" system: demo-system\n"
" size: 1024\n"
" - name: boot-alt.bin\n"
" system: demo-system\n"
" size: 1024\n"
" - name: shared.bin\n"
" system: demo-system\n"
" size: 1024\n"
)
found = {e["name"] for e in self._scan(profiles)}
self.assertNotIn(
"flag00.bin", found,
"a single name match must not drag its neighbours into the pack",
)
self.assertEqual(
found, {"boot.bin", "boot-alt.bin", "boot-jp.bin", "shared.bin"}
)
def test_an_entry_without_a_size_is_not_a_scan_seed(self):
"""No shape declared means the scan would take the whole directory."""
profiles = self._write_profile(
"emulator: demo\n"
"type: libretro\n"
"display_name: Demo\n"
"bios_mode: agnostic\n"
"systems: [demo-system]\n"
"cores: [demo]\n"
"files:\n"
" - name: shared.bin\n"
" system: demo-system\n"
" - name: boot.bin\n"
" system: demo-system\n"
)
self.assertEqual(self._scan(profiles), [])
def test_what_the_scan_emits_is_named_by_content(self):
"""A filename alone sends the packing step back to a by-name lookup."""
profiles = self._write_profile(
"emulator: demo\n"
"type: libretro\n"
"display_name: Demo\n"
"bios_mode: agnostic\n"
"systems: [demo-system]\n"
"cores: [demo]\n"
"files:\n"
" - name: boot.bin\n"
" system: demo-system\n"
" size: 1024\n"
" - name: boot-alt.bin\n"
" system: demo-system\n"
" size: 1024\n"
)
self.assertTrue(self._scan(profiles))
for extra in self._scan(profiles):
self.assertIn("sha1", extra, f"{extra['name']} carries no identity")
path, status = common.resolve_local_file(extra, self.db)
self.assertEqual(status, "sha1_exact")
self.assertTrue(path.endswith(extra["name"]))
class PathTailBeatsABareName(unittest.TestCase):
"""A destination is written from the emulator's point of view.
"pcsx2/resources/GameIndex.yaml" and the repo's
"bios/Sony/PlayStation 2/resources/GameIndex.yaml" meet on a tail, not on
the whole string, so the lookup fell through to the name and returned
whichever namesake sorted first.
"""
def setUp(self):
self._tmp = tempfile.TemporaryDirectory()
self.root = Path(self._tmp.name)
files, by_name, by_suffix = {}, {}, {}
for relative, filler in (
("bios/Sony/Console/resources/index.yaml", b"R"),
("bios/Other/app/assets/index.yaml", b"W"),
):
sha1, record = _blob(self.root, relative, filler)
files[sha1] = record
by_name.setdefault("index.yaml", []).append(sha1)
parts = relative.split("/")
for start in range(len(parts)):
by_suffix.setdefault("/".join(parts[start:]), []).append(sha1)
self.db = {
"files": files,
"indexes": {
"by_name": by_name,
"by_md5": {},
"by_sha256": {},
"by_crc32": {},
"by_path_suffix": by_suffix,
},
}
def tearDown(self):
self._tmp.cleanup()
def test_the_tail_of_the_declared_path_decides(self):
entry = {"name": "index.yaml", "path": "app/resources/index.yaml"}
path, status = common.resolve_local_file(
entry, self.db, dest_hint=entry["path"]
)
self.assertEqual(status, "path_exact")
self.assertIn("Sony/Console/resources", path)
def test_a_bare_name_is_never_reached_through_the_tail(self):
"""The tail stops above the filename: that is the weaker step."""
entry = {"name": "index.yaml", "path": "nowhere/index.yaml"}
_path, status = common.resolve_local_file(
entry, self.db, dest_hint=entry["path"]
)
self.assertEqual(status, "name_exact")
if __name__ == "__main__":
unittest.main()