avocado.multiplexer: Construct the tree directly from yaml file

Instead of creating OrderedDicts and then converting it into
tree structure, this modifies the `mapping` constructor to create
the tree structure directly. This way we only walk through the yaml
file once.

Also remove the `tree_unittest.TestReadYAML` selftest as it lost it's
meaning. Valures are checked in the TestTreeNode selftest.
Signed-off-by: NLukáš Doktor <ldoktor@redhat.com>

avocado/core/tree.py

@@ -34,7 +34,6 @@ original base tree code and re-license under GPLv2+, given that GPLv3 and GPLv2
 """
 
 import collections
-
 import yaml
 
 
@@ -65,8 +64,21 @@ class TreeNode(object):
     def __iter__(self):
         return self.iter_leaves()
 
+    def __eq__(self, other):
+        if isinstance(other, str):  # Compare names
+            if self.name == other:
+                return True
+        elif isinstance(other, self.__class__):
+            return self.__dict__ == other.__dict__
+        return False
+
     def add_child(self, node):
         if isinstance(node, self.__class__):
+            if node.name in self.children:
+                raise NotImplementedError('Adding children with the same '
+                                          'name is not implemented yet.'
+                                          '\nnode: %s\nchildren: %s'
+                                          % (node, self.children))
             node.parent = self
             self.children.append(node)
         else:
@@ -117,7 +129,7 @@ class TreeNode(object):
     def get_environment(self):
         def update_or_extend(target, source):
             for k, _ in source.items():
-                if target.has_key(k) and isinstance(target[k], list):
+                if k in target and isinstance(target[k], list):
                     target[k].extend(source[k])
                 else:
                     if isinstance(source[k], list):
@@ -207,50 +219,63 @@ class TreeNode(object):
         return self
 
 
-def ordered_load(stream, Loader=yaml.Loader,
-                 object_pairs_hook=collections.OrderedDict):
-    class OrderedLoader(Loader):
-        pass
-    OrderedLoader.add_constructor(yaml.resolver.BaseResolver.DEFAULT_MAPPING_TAG,
-                                  lambda loader, node:
-                                  object_pairs_hook(loader.construct_pairs(node)))
-    return yaml.load(stream, OrderedLoader)
+def _create_from_yaml(stream):
+    """ Create tree structure from yaml stream """
+    class Value(tuple):
 
+        """ Used to mark values to simplify checking for node vs. value """
+        pass
 
-def read_ordered_yaml(fileobj):
+    def tree_node_from_values(name, values):
+        """ Create $name node and add values  """
+        node_children = []
+        node_values = []
+        for value in values:
+            if isinstance(value, TreeNode):
+                node_children.append(value)
+            else:
+                node_values.append(value)
+        return TreeNode(name, dict(node_values), children=node_children)
+
+    def mapping_to_tree_loader(loader, node):
+        def is_node(values):
+            if isinstance(values, dict):    # dicts are always nodes
+                return True
+            elif (isinstance(values, list) and values
+                  and isinstance(values[0], (Value, TreeNode))):
+                # When any value is TreeNode or Value, all of them are already
+                # parsed and we can wrap them into self
+                return True
+
+        _value = loader.construct_pairs(node)
+        objects = []
+        for name, values in _value:
+            if is_node(values):    # New node
+                objects.append(tree_node_from_values(name, values))
+            elif values is None:            # Empty node
+                objects.append(TreeNode(name))
+            else:                           # Values
+                objects.append(Value((name, values)))
+        return objects
+    yaml.Loader.add_constructor(yaml.resolver.BaseResolver.DEFAULT_MAPPING_TAG,
+                                mapping_to_tree_loader)
+    return tree_node_from_values('', yaml.load(stream, yaml.Loader))
+
+
+def create_from_yaml(fileobj):
+    """
+    Create tree structure from yaml-like file
+    :param fileobj: File object to be processed
+    :raise SyntaxError: When yaml-file is corrupted
+    :return: Root of the created tree structure
+    """
     try:
-        data = ordered_load(fileobj.read())
+        data = _create_from_yaml(fileobj.read())
     except (yaml.scanner.ScannerError, yaml.parser.ParserError) as err:
         raise SyntaxError(err)
     return data
 
 
-def create_from_ordered_data(data, tree=None, root=None, name=''):
-    if tree is None:
-        tree = TreeNode(name)
-    if root is None:
-        root = tree
-    if isinstance(data, dict):
-        for key, value in data.items():
-            if isinstance(value, dict):
-                node = TreeNode(key)
-                tree.add_child(node)
-                create_from_ordered_data(value, node, root)
-            elif value is None:
-                # Leaf without variable
-                node = TreeNode(key)
-                tree.add_child(node)
-            else:
-                # Node/leaf with variable
-                tree.value[key] = value
-    return root
-
-
-def create_from_yaml(input_yaml):
-    data = read_ordered_yaml(input_yaml)
-    return create_from_ordered_data(data)
-
-
 def path_parent(path):
     """
     From a given path, return its parent path.

avocado/plugins/multiplexer.py

@@ -67,8 +67,7 @@ class Multiplexer(plugin.Plugin):
 
         if args.tree:
             view.notify(event='message', msg='Config file tree structure:')
-            data = tree.read_ordered_yaml(open(multiplex_file))
-            t = tree.create_from_ordered_data(data)
+            t = tree.create_from_yaml(open(multiplex_file))
             t = tree.apply_filters(t, args.filter_only, args.filter_out)
             view.notify(event='minor', msg=t.get_ascii())
             sys.exit(error_codes.numeric_status['AVOCADO_ALL_OK'])

selftests/all/unit/avocado/multiplexer_unittest.py

@@ -25,7 +25,7 @@ class TestAnySibling(unittest.TestCase):
         os = t.add_child(TreeNode('os'))
         linux = os.add_child(TreeNode('linux'))
         self.mint = linux.add_child(TreeNode('mint'))
-        self.fedora = linux.add_child(TreeNode('mint'))
+        self.fedora = linux.add_child(TreeNode('fedora'))
         win = os.add_child(TreeNode('win'))
         self.winxp = win.add_child(TreeNode('winxp'))
         self.win7 = win.add_child(TreeNode('win7'))
@@ -53,7 +53,6 @@ class TestAnySibling(unittest.TestCase):
 class TestMultiplex(unittest.TestCase):
 
     def setUp(self):
-
         t1 = TreeNode()
         e = t1.add_child(TreeNode('env'))
         e.add_child(TreeNode('production'))
@@ -71,7 +70,7 @@ class TestMultiplex(unittest.TestCase):
         st = t2.add_child(TreeNode('tests')).add_child(TreeNode('sync_test'))
         st.add_child(TreeNode('standard'))
         st.add_child(TreeNode('aggressive'))
-        pt = t2.add_child(TreeNode('tests')).add_child(TreeNode('ping_test'))
+        pt = t2.children[1].add_child(TreeNode('ping_test'))
         pt.add_child(TreeNode('standard'))
         pt.add_child(TreeNode('aggressive'))
         self.tree2 = t2

selftests/all/unit/avocado/tree_unittest.py

@@ -37,42 +37,22 @@ os:
 """
 
 
-class TestReadYAML(unittest.TestCase):
-
-    def setUp(self):
-        self.yaml = StringIO.StringIO(source_yaml)
-
-    def test_read_yaml_values(self):
-        data = read_ordered_yaml(self.yaml)
-        self.assertIsInstance(data, dict)
-        self.assertIn('hw', data)
-        self.assertIn('os', data)
-        self.assertIn('cpu', data['hw'])
-        self.assertIn('intel', data['hw']['cpu'])
-        self.assertIsInstance(data['hw']['cpu']['intel']['arch'], list)
-        self.assertIn('arm', data['hw']['cpu'])
-        self.assertIsInstance(data['hw']['cpu']['arm']['arch'], list)
-        self.assertIn('os', data)
-        self.assertIn('linux', data['os'])
-        self.assertIn('dev-tools', data['os']['linux'])
-        self.assertIn('fedora', data['os']['linux'])
-        self.assertIn('mint', data['os']['linux'])
-        self.assertIn('centos', data['os']['linux'])
-        self.assertIn('win', data['os'])
-        self.assertIn('dev-tools', data['os']['win'])
-        self.assertIn('win7', data['os']['win'])
-        self.assertIn('win8', data['os']['win'])
-
-
 class TestTreeNode(unittest.TestCase):
 
     def setUp(self):
-        self.data = read_ordered_yaml(StringIO.StringIO(source_yaml))
-        self.treenode = create_from_ordered_data(self.data)
+        self.treenode = create_from_yaml(StringIO.StringIO(source_yaml))
 
     def test_create_treenode(self):
         self.assertIsInstance(self.treenode, TreeNode)
 
+    def test_comparison(self):
+        self.assertEqual(self.treenode.children[0], self.treenode.children[0])
+        self.assertEqual(self.treenode.children[0], "hw")
+        self.assertEqual("hw", self.treenode.children[0])
+        self.assertNotEqual(self.treenode.children[0],
+                            self.treenode.children[1])
+        self.assertNotEqual(self.treenode.children[0], "nothw")
+
     def test_node_order(self):
         self.assertEqual(self.treenode.children[0].name, 'hw')
         self.assertEqual(self.treenode.children[0].children[0].name, 'cpu')