2026-1-6

venv/Lib/site-packages/whoosh/util/loading.py

@@ -0,0 +1,84 @@
+# Copyright 2012 Matt Chaput. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#
+#    1. Redistributions of source code must retain the above copyright notice,
+#       this list of conditions and the following disclaimer.
+#
+#    2. Redistributions in binary form must reproduce the above copyright
+#       notice, this list of conditions and the following disclaimer in the
+#       documentation and/or other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY MATT CHAPUT ``AS IS'' AND ANY EXPRESS OR
+# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
+# EVENT SHALL MATT CHAPUT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
+# OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+# LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+# NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
+# EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+# The views and conclusions contained in the software and documentation are
+# those of the authors and should not be interpreted as representing official
+# policies, either expressed or implied, of Matt Chaput.
+
+import pickle
+
+
+class RenamingUnpickler(pickle.Unpickler):
+    """Subclasses ``pickle.Unpickler`` to allow remapping of class names before
+    loading them.
+    """
+
+    def __init__(self, f, objmap, shortcuts=None):
+        pickle.Unpickler.__init__(self, f)
+
+        if shortcuts:
+            objmap = dict((k % shortcuts, v % shortcuts)
+                          for k, v in objmap.items())
+        self._objmap = objmap
+
+    def find_class(self, modulename, objname):
+        fqname = "%s.%s" % (modulename, objname)
+        if fqname in self._objmap:
+            fqname = self._objmap[fqname]
+        try:
+            obj = find_object(fqname)
+        except ImportError:
+            raise ImportError("Couldn't find %r" % fqname)
+        return obj
+
+
+def find_object(name, blacklist=None, whitelist=None):
+    """Imports and returns an object given a fully qualified name.
+
+    >>> find_object("whoosh.analysis.StopFilter")
+    <class 'whoosh.analysis.StopFilter'>
+    """
+
+    if blacklist:
+        for pre in blacklist:
+            if name.startswith(pre):
+                raise TypeError("%r: can't instantiate names starting with %r"
+                                % (name, pre))
+    if whitelist:
+        passes = False
+        for pre in whitelist:
+            if name.startswith(pre):
+                passes = True
+                break
+        if not passes:
+            raise TypeError("Can't instantiate %r" % name)
+
+    lastdot = name.rfind(".")
+
+    assert lastdot > -1, "Name %r must be fully qualified" % name
+    modname = name[:lastdot]
+    clsname = name[lastdot + 1:]
+
+    mod = __import__(modname, fromlist=[clsname])
+    cls = getattr(mod, clsname)
+    return cls