Improvements to try resolve the issues with login checksums.

ptlinux/runtime.py

@@ -4,6 +4,7 @@ from __future__ import annotations
 
 from dataclasses import asdict, dataclass
 from datetime import datetime
+import hashlib
 import json
 import os
 from pathlib import Path
@@ -33,6 +34,7 @@ WINETRICKS_CODEPAGE_PROBE = (
 WINETRICKS_PROTON7_PROBE = 'winetricks_early_wine_arch cmd.exe /c "echo %$1%"'
 RUNTIME_DEFAULT_SYNC = "runtime-default"
 CACHYOS_MARKER = "cachyos"
+GAME_RUNTIME_CONFIGURATION_VERSION = 1
 
 
 class RuntimeErrorPT(RuntimeError):
@@ -159,6 +161,8 @@ def prepare_game_runtime(
 	elif selection.kind in {"proton7", "proton7-container"}:
 		if not selection.proton_path or not selection.steam_root:
 			raise RuntimeErrorPT("incomplete Proton 7 runtime selection")
+		if not runner.dry_run and _game_runtime_ready(paths, selection):
+			return results
 		if not runner.dry_run:
 			paths.compat_data.mkdir(parents=True, exist_ok=True)
 		proton = Path(selection.proton_path)
@@ -237,11 +241,13 @@ def prepare_game_runtime(
 		raise RuntimeErrorPT(f"unsupported runtime kind: {selection.kind}")
 	if not runner.dry_run:
 		_write_json(
-			paths.state / "game-runtime.json",
+			paths.game_runtime_marker,
 			{
+				"configuration_version": GAME_RUNTIME_CONFIGURATION_VERSION,
 				"configured_at": datetime.now().astimezone().isoformat(),
 				"native_d3d43": True,
 				"dxvk_d3d9_override": DXVK_D3D9_OVERRIDE,
+				"proton_identity": _proton_identity(selection),
 				"runtime": asdict(selection),
 			},
 		)
@@ -572,6 +578,69 @@ def _proton_prefix_ready(prefix: Path) -> bool:
 	).exists()
 
 
+def _game_runtime_ready(paths: AppPaths, selection: RuntimeSelection) -> bool:
+	marker = _read_json(paths.game_runtime_marker)
+	identity = _proton_identity(selection)
+	if marker is None or identity is None:
+		return False
+	if marker.get("configuration_version") != GAME_RUNTIME_CONFIGURATION_VERSION:
+		return False
+	if marker.get("runtime") != asdict(selection):
+		return False
+	if marker.get("proton_identity") != identity:
+		return False
+	if marker.get("native_d3d43") is not True:
+		return False
+	if marker.get("dxvk_d3d9_override") != DXVK_D3D9_OVERRIDE:
+		return False
+	if not _proton_prefix_ready(paths.proton_prefix):
+		return False
+	if not native_d3d_ready(paths.proton_prefix):
+		return False
+	if not _d3d9_override_ready(paths.proton_prefix):
+		return False
+	return _proton_game_link_ready(paths)
+
+
+def _d3d9_override_ready(prefix: Path) -> bool:
+	try:
+		registry = (prefix / "user.reg").read_text(
+			encoding="utf-8",
+			errors="replace",
+		).casefold()
+	except OSError:
+		return False
+	return f'"d3d9"="{DXVK_D3D9_OVERRIDE}"' in registry
+
+
+def _proton_game_link_ready(paths: AppPaths) -> bool:
+	link = paths.proton_prefix / "drive_c/Program Files (x86)/Pristontale EU"
+	if not link.is_symlink():
+		return False
+	try:
+		return link.resolve(strict=True) == paths.runtime_view.resolve(strict=True)
+	except (OSError, RuntimeError):
+		return False
+
+
+def _proton_identity(selection: RuntimeSelection) -> dict[str, str] | None:
+	if not selection.proton_path:
+		return None
+	proton = Path(selection.proton_path)
+	identity_paths = {
+		"proton": proton,
+		"version": proton.parent / "version",
+		"toolmanifest": proton.parent / "toolmanifest.vdf",
+	}
+	identity: dict[str, str] = {}
+	for name, path in identity_paths.items():
+		try:
+			identity[name] = _sha256(path)
+		except OSError:
+			return None
+	return identity
+
+
 def _find_proton_wine_tools(proton: Path) -> tuple[Path, Path] | None:
 	for directory in (proton.parent / "files/bin", proton.parent / "dist/bin"):
 		wine = directory / "wine"
@@ -586,3 +655,19 @@ def _write_json(path: Path, value: object) -> None:
 	temporary = path.with_name(f".{path.name}.{os.getpid()}.tmp")
 	temporary.write_text(json.dumps(value, indent=2, sort_keys=True) + "\n", encoding="utf-8")
 	temporary.replace(path)
+
+
+def _read_json(path: Path) -> dict[str, object] | None:
+	try:
+		value = json.loads(path.read_text(encoding="utf-8"))
+	except (OSError, UnicodeError, json.JSONDecodeError):
+		return None
+	return value if isinstance(value, dict) else None
+
+
+def _sha256(path: Path) -> str:
+	digest = hashlib.sha256()
+	with path.open("rb") as handle:
+		for chunk in iter(lambda: handle.read(1024 * 1024), b""):
+			digest.update(chunk)
+	return digest.hexdigest()