Move common libs to libs/common

libs/common/beets/vfs.py

@@ -0,0 +1,53 @@
+# -*- coding: utf-8 -*-
+# This file is part of beets.
+# Copyright 2016, Adrian Sampson.
+#
+# Permission is hereby granted, free of charge, to any person obtaining
+# a copy of this software and associated documentation files (the
+# "Software"), to deal in the Software without restriction, including
+# without limitation the rights to use, copy, modify, merge, publish,
+# distribute, sublicense, and/or sell copies of the Software, and to
+# permit persons to whom the Software is furnished to do so, subject to
+# the following conditions:
+#
+# The above copyright notice and this permission notice shall be
+# included in all copies or substantial portions of the Software.
+
+"""A simple utility for constructing filesystem-like trees from beets
+libraries.
+"""
+from __future__ import division, absolute_import, print_function
+
+from collections import namedtuple
+from beets import util
+
+Node = namedtuple('Node', ['files', 'dirs'])
+
+
+def _insert(node, path, itemid):
+    """Insert an item into a virtual filesystem node."""
+    if len(path) == 1:
+        # Last component. Insert file.
+        node.files[path[0]] = itemid
+    else:
+        # In a directory.
+        dirname = path[0]
+        rest = path[1:]
+        if dirname not in node.dirs:
+            node.dirs[dirname] = Node({}, {})
+        _insert(node.dirs[dirname], rest, itemid)
+
+
+def libtree(lib):
+    """Generates a filesystem-like directory tree for the files
+    contained in `lib`. Filesystem nodes are (files, dirs) named
+    tuples in which both components are dictionaries. The first
+    maps filenames to Item ids. The second maps directory names to
+    child node tuples.
+    """
+    root = Node({}, {})
+    for item in lib.items():
+        dest = item.destination(fragment=True)
+        parts = util.components(dest)
+        _insert(root, parts, item.id)
+    return root