Restore _PreciseSelector

Author: barneygale

Lib/pathlib.py

@@ -67,7 +67,7 @@ def _is_case_sensitive(flavour):
 #
 
 @functools.lru_cache()
-def _make_selector(pattern_parts, case_sensitive):
+def _make_selector(pattern_parts, flavour, case_sensitive):
     pat = pattern_parts[0]
     child_parts = pattern_parts[1:]
     if not pat:
@@ -78,19 +78,21 @@ def _make_selector(pattern_parts, case_sensitive):
         cls = _ParentSelector
     elif '**' in pat:
         raise ValueError("Invalid pattern: '**' can only be an entire path component")
-    else:
+    elif _is_wildcard_pattern(pat) or case_sensitive != _is_case_sensitive(flavour):
         cls = _WildcardSelector
-    return cls(pat, child_parts, case_sensitive)
+    else:
+        cls = _PreciseSelector
+    return cls(pat, child_parts, flavour, case_sensitive)
 
 
 class _Selector:
     """A selector matches a specific glob pattern part against the children
     of a given path."""
 
-    def __init__(self, child_parts, case_sensitive):
+    def __init__(self, child_parts, flavour, case_sensitive):
         self.child_parts = child_parts
         if child_parts:
-            self.successor = _make_selector(child_parts, case_sensitive)
+            self.successor = _make_selector(child_parts, flavour, case_sensitive)
             self.dironly = True
         else:
             self.successor = _TerminatingSelector()
@@ -100,37 +102,55 @@ def select_from(self, parent_path):
         """Iterate over all child paths of `parent_path` matched by this
         selector.  This can contain parent_path itself."""
         path_cls = type(parent_path)
+        is_dir = path_cls.is_dir
+        exists = path_cls.exists
         scandir = path_cls._scandir
-        if not parent_path.is_dir():
+        if not is_dir(parent_path):
             return iter([])
-        return self._select_from(parent_path, scandir)
+        return self._select_from(parent_path, is_dir, exists, scandir)
 
 
 class _TerminatingSelector:
 
-    def _select_from(self, parent_path, scandir):
+    def _select_from(self, parent_path, is_dir, exists, scandir):
         yield parent_path
 
 
 class _ParentSelector(_Selector):
 
-    def __init__(self, name, child_parts, case_sensitive):
-        _Selector.__init__(self, child_parts, case_sensitive)
+    def __init__(self, name, child_parts, flavour, case_sensitive):
+        _Selector.__init__(self, child_parts, flavour, case_sensitive)
 
-    def _select_from(self,  parent_path, scandir):
+    def _select_from(self,  parent_path, is_dir, exists, scandir):
         path = parent_path._make_child_relpath('..')
-        for p in self.successor._select_from(path, scandir):
+        for p in self.successor._select_from(path, is_dir, exists, scandir):
             yield p
 
 
+class _PreciseSelector(_Selector):
+
+    def __init__(self, name, child_parts, flavour, case_sensitive):
+        self.name = name
+        _Selector.__init__(self, child_parts, flavour, case_sensitive)
+
+    def _select_from(self, parent_path, is_dir, exists, scandir):
+        try:
+            path = parent_path._make_child_relpath(self.name)
+            if (is_dir if self.dironly else exists)(path):
+                for p in self.successor._select_from(path, is_dir, exists, scandir):
+                    yield p
+        except PermissionError:
+            return
+
+
 class _WildcardSelector(_Selector):
 
-    def __init__(self, pat, child_parts, case_sensitive):
+    def __init__(self, pat, child_parts, flavour, case_sensitive):
         flags = re.NOFLAG if case_sensitive else re.IGNORECASE
         self.match = re.compile(fnmatch.translate(pat), flags=flags).fullmatch
-        _Selector.__init__(self, child_parts, case_sensitive)
+        _Selector.__init__(self, child_parts, flavour, case_sensitive)
 
-    def _select_from(self, parent_path, scandir):
+    def _select_from(self, parent_path, is_dir, exists, scandir):
         try:
             # We must close the scandir() object before proceeding to
             # avoid exhausting file descriptors when globbing deep trees.
@@ -151,18 +171,18 @@ def _select_from(self, parent_path, scandir):
                 name = entry.name
                 if self.match(name):
                     path = parent_path._make_child_relpath(name)
-                    for p in self.successor._select_from(path, scandir):
+                    for p in self.successor._select_from(path, is_dir, exists, scandir):
                         yield p
         except PermissionError:
             return
 
 
 class _RecursiveWildcardSelector(_Selector):
 
-    def __init__(self, pat, child_parts, case_sensitive):
-        _Selector.__init__(self, child_parts, case_sensitive)
+    def __init__(self, pat, child_parts, flavour, case_sensitive):
+        _Selector.__init__(self, child_parts, flavour, case_sensitive)
 
-    def _iterate_directories(self, parent_path, scandir):
+    def _iterate_directories(self, parent_path, is_dir, scandir):
         yield parent_path
         try:
             # We must close the scandir() object before proceeding to
@@ -178,18 +198,18 @@ def _iterate_directories(self, parent_path, scandir):
                         raise
                 if entry_is_dir and not entry.is_symlink():
                     path = parent_path._make_child_relpath(entry.name)
-                    for p in self._iterate_directories(path, scandir):
+                    for p in self._iterate_directories(path, is_dir, scandir):
                         yield p
         except PermissionError:
             return
 
-    def _select_from(self, parent_path, scandir):
+    def _select_from(self, parent_path, is_dir, exists, scandir):
         try:
             yielded = set()
             try:
                 successor_select = self.successor._select_from
-                for starting_point in self._iterate_directories(parent_path, scandir):
-                    for p in successor_select(starting_point, scandir):
+                for starting_point in self._iterate_directories(parent_path, is_dir, scandir):
+                    for p in successor_select(starting_point, is_dir, exists, scandir):
                         if p not in yielded:
                             yield p
                             yielded.add(p)
@@ -839,7 +859,7 @@ def glob(self, pattern, *, case_sensitive=None):
             pattern_parts.append('')
         if case_sensitive is None:
             case_sensitive = _is_case_sensitive(self._flavour)
-        selector = _make_selector(tuple(pattern_parts), case_sensitive)
+        selector = _make_selector(tuple(pattern_parts), self._flavour, case_sensitive)
         for p in selector.select_from(self):
             yield p
 
@@ -856,7 +876,7 @@ def rglob(self, pattern, *, case_sensitive=None):
             pattern_parts.append('')
         if case_sensitive is None:
             case_sensitive = _is_case_sensitive(self._flavour)
-        selector = _make_selector(("**",) + tuple(pattern_parts), case_sensitive)
+        selector = _make_selector(("**",) + tuple(pattern_parts), self._flavour, case_sensitive)
         for p in selector.select_from(self):
             yield p