From 71c9fa26570d8c03bd08c799104aac80a1ced7ff Mon Sep 17 00:00:00 2001
From: Ryan Young <ryan@youngryan.com>
Date: Thu, 19 Mar 2020 13:17:17 -0700
Subject: [PATCH] Ignore exceptions when loading MSTS data.

---
 autotable/mstsinstall.py | 52 ++++++++++++++++++++++++----------------
 1 file changed, 31 insertions(+), 21 deletions(-)

diff --git a/autotable/mstsinstall.py b/autotable/mstsinstall.py
index 00fde76..ea3620c 100644
--- a/autotable/mstsinstall.py
+++ b/autotable/mstsinstall.py
@@ -64,7 +64,7 @@ def __init__(self, data: kf.Object):
             self.latlon = _latlon(tile_x, tile_z, ew, ns)
 
     def __init__(self, path: Path, encoding=ENCODING):
-        df = one(_echild(path, 'trk'))
+        df = one(_echildren(path, 'trk'))
         with open(df, encoding=encoding) as fp:
             d = kf.load(fp)
         desc = d['Tr_RouteFile']
@@ -89,10 +89,8 @@ def stations(self) -> typ.Mapping[Station, typ.Iterable[PlatformItem]]:
             d = kf.load(fp)
         table = d['TrItemTable']
 
-        with ProcessPoolExecutor() as executor:
-            platforms = executor.map(Route.PlatformItem, table['PlatformItem'])
         res = defaultdict(list)
-        for platform in platforms:
+        for platform in _pmap(table['PlatformItem'], Route.PlatformItem):
             res[platform.station].append(platform)
         return res
 
@@ -100,14 +98,9 @@ def station_names(self) -> typ.Iterable[Station]: return self.stations().keys()
 
     @lru_cache(maxsize=1)
     def train_paths(self) -> typ.Mapping[Ident, TrainPath]:
-        route_paths = _echild(_ichild(self.path, 'paths'), 'pat')
-        with ProcessPoolExecutor() as executor:
-            futures = []
-            for path in route_paths:
-                futures.append(
-                    executor.submit(Route.TrainPath, path, encoding=self._encoding))
-            loaded_paths = [future.result() for future in as_completed(futures)]
-        return {path.id: path for path in loaded_paths}
+        route_paths = _echildren(_ichild(self.path, 'paths'), 'pat')
+        return {path.id: path for path
+                in _pmap(route_paths, Route.TrainPath, encoding=self._encoding)}
 
     def train_path(self, id: str) -> TrainPath:
         return self.train_paths()[Ident(id)]
@@ -130,10 +123,8 @@ def __init__(self, path: Path, encoding=ENCODING):
 
     @lru_cache(maxsize=1)
     def routes(self) -> typ.Mapping[Ident, Route]:
-        route_dirs = (child for child in _ichild(self.path, 'routes').iterdir()
-                      if child.is_dir())
-        with ProcessPoolExecutor() as executor:
-            return {route.id: route for route in executor.map(Route, route_dirs)}
+        route_dirs = _dchildren(_ichild(self.path, 'routes'))
+        return {route.id: route for route in _pmap(route_dirs, Route)}
 
     def route(self, id: str) -> Route:
         return self.routes()[Ident(id)]
@@ -141,26 +132,45 @@ def route(self, id: str) -> Route:
     @lru_cache(maxsize=1)
     def consists(self) -> typ.Mapping[Ident, Consist]:
         con_files = \
-            _echild(_ichild(_ichild(self.path, 'trains'), 'consists'), 'con')
-        with ProcessPoolExecutor() as executor:
-            return {consist.id: consist
-                    for consist in executor.map(Consist, con_files)}
+            _echildren(_ichild(_ichild(self.path, 'trains'), 'consists'), 'con')
+        return {consist.id: consist for consist in _pmap(con_files, Consist)}
 
     def consist(self, id: str) -> Consist:
         return self.consists()[Ident(id)]
 
 
+
+_T = typ.TypeVar('_T')
+_U = typ.TypeVar('_U')
+
+def _pmap(inputs: typ.Iterable[_T], fn: typ.Callable[..., _U], *args, **kwargs) \
+        -> typ.Generator[_U, None, None]:
+    with ProcessPoolExecutor() as executor:
+        futures = [executor.submit(fn, input, *args, **kwargs) for input in inputs]
+        for future in as_completed(futures):
+            try:
+                result = future.result()
+            except:
+                pass # Just eat exceptions.
+            else:
+                yield result
+
+
 def _ichild(path: Path, name: str) -> Path:
     matches = (child for child in path.iterdir()
                if child.name.casefold() == name.casefold())
     return one(matches, too_short=FileNotFoundError, too_long=LookupError)
 
 
-def _echild(path: Path, extension: str) -> typ.Iterable[Path]:
+def _echildren(path: Path, extension: str) -> typ.Iterable[Path]:
     suffix = f'.{extension.casefold()}'
     return (child for child in path.iterdir() if child.suffix.casefold() == suffix)
 
 
+def _dchildren(path: Path) -> typ.Iterable[Path]:
+    return (child for child in path.iterdir() if child.is_dir())
+
+
 def _latlon(tile_x: int, tile_z: int, ew: float, ns: float) \
         -> typ.Tuple[float, float]:
     # Conversion is abridged from Open Rails (Orts.Common.WorldLatLon.ConvertWTC)