Merge pull request #137 from zopefoundation/ztutils-py3k

Make ZTUtils tests pass on Py3k

src/ZTUtils/Tree.py

@@ -20,11 +20,6 @@
 from ComputedAttribute import ComputedAttribute
 import six
 
-try:
-    maketrans = str.maketrans
-except AttributeError:  # Py2
-    from string import maketrans
-
 
 class TreeNode(Explicit):
     __allow_access_to_unprotected_subobjects__ = 1
@@ -76,32 +71,15 @@ class TreeMaker:
     __allow_access_to_unprotected_subobjects__ = 1
 
     _id = 'tpId'
+    _assume_children = False
+    _expand_root = True
     _values = 'tpValues'
-    _assume_children = 0
     _values_filter = None
     _values_function = None
     _state_function = None
-    _expand_root = 1
 
     _cached_children = None
 
-    def setChildAccess(self, attrname=_marker, filter=_marker,
-                       function=_marker):
-        '''Set the criteria for fetching child nodes.
-
-        Child nodes can be accessed through either an attribute name
-        or callback function.  Children fetched by attribute name can
-        be filtered through a callback function.
-        '''
-        if function is _marker:
-            self._values_function = None
-            if attrname is not _marker:
-                self._values = str(attrname)
-            if filter is not _marker:
-                self._values_filter = filter
-        else:
-            self._values_function = function
-
     def setIdAttr(self, id):
         """Set the attribute or method name called to get a unique Id.
 
@@ -137,6 +115,23 @@ def setAssumeChildren(self, assume):
         """
         self._assume_children = assume and True or False
 
+    def setChildAccess(self, attrname=_marker, filter=_marker,
+                       function=_marker):
+        '''Set the criteria for fetching child nodes.
+
+        Child nodes can be accessed through either an attribute name
+        or callback function.  Children fetched by attribute name can
+        be filtered through a callback function.
+        '''
+        if function is _marker:
+            self._values_function = None
+            if attrname is not _marker:
+                self._values = str(attrname)
+            if filter is not _marker:
+                self._values_filter = filter
+        else:
+            self._values_function = function
+
     def setStateFunction(self, function):
         """Set the expansion state function.
 
@@ -153,41 +148,6 @@ def setStateFunction(self, function):
         """
         self._state_function = function
 
-    def tree(self, root, expanded=None, subtree=0):
-        '''Create a tree from root, with specified nodes expanded.
-
-        "expanded" must be false, true, or a mapping.
-        Each key of the mapping is the id of a top-level expanded
-        node, and each value is the "expanded" value for the
-        children of that node.
-        '''
-        node = self.node(root)
-        child_exp = expanded
-        if not simple_type(expanded):
-            # Assume a mapping
-            expanded = node.id in expanded
-            child_exp = child_exp.get(node.id)
-
-        expanded = expanded or (not subtree and self._expand_root)
-        # Set state to 0 (leaf), 1 (opened), or -1 (closed)
-        state = self.hasChildren(root) and (expanded or -1)
-        if self._state_function is not None:
-            state = self._state_function(node.object, state)
-        node.state = state
-        if state > 0:
-            for child in self.getChildren(root):
-                node._add_child(self.tree(child, child_exp, 1))
-
-        if not subtree:
-            node.depth = 0
-        return node
-
-    def node(self, object):
-        node = TreeNode()
-        node.object = object
-        node.id = b2a(self.getId(object))
-        return node
-
     def getId(self, object):
         id_attr = self._id
         if hasattr(object, id_attr):
@@ -199,13 +159,25 @@ def getId(self, object):
             return str(object._p_oid)
         return id(object)
 
+    def node(self, object):
+        node = TreeNode()
+        node.object = object
+        obid = self.getId(object)
+        node.id = b2a(self.getId(object))
+        return node
+
     def hasChildren(self, object):
         if self._assume_children:
             return 1
         # Cache generated children for a subsequent call to getChildren
         self._cached_children = (object, self.getChildren(object))
         return not not self._cached_children[1]
 
+    def filterChildren(self, children):
+        if self._values_filter:
+            return self._values_filter(children)
+        return children
+
     def getChildren(self, object):
         # Check and clear cache first
         if self._cached_children is not None:
@@ -225,40 +197,64 @@ def getChildren(self, object):
 
         return self.filterChildren(children)
 
-    def filterChildren(self, children):
-        if self._values_filter:
-            return self._values_filter(children)
-        return children
+    def tree(self, root, expanded=None, subtree=0):
+        '''Create a tree from root, with specified nodes expanded.
+
+        "expanded" must be false, true, or a mapping.
+        Each key of the mapping is the id of a top-level expanded
+        node, and each value is the "expanded" value for the
+        children of that node.
+        '''
+        node = self.node(root)
+        child_exp = expanded
+        if not simple_type(expanded):
+            # Assume a mapping
+            expanded = node.id in expanded
+            child_exp = child_exp.get(node.id)
+
+        expanded = expanded or (not subtree and self._expand_root)
+        # Set state to 0 (leaf), 1 (opened), or -1 (closed)
+        state = self.hasChildren(root) and (expanded or -1)
+        if self._state_function is not None:
+            state = self._state_function(node.object, state)
+        node.state = state
+        if state > 0:
+            for child in self.getChildren(root):
+                node._add_child(self.tree(child, child_exp, 1))
 
+        if not subtree:
+            node.depth = 0
+        return node
 
-def simple_type(ob,
-                is_simple={type(''): 1, type(0): 1, type(0.0): 1,
-                           type(None): 1}.__contains__):
-    return is_simple(type(ob))
 
+_SIMPLE_TYPES = set([type(u''), type(b''), type(0), type(0.0), type(None)])
 
-a2u_map = maketrans('+/=', '-._')
-u2a_map = maketrans('-._', '+/=')
+def simple_type(ob):
+    return type(ob) in _SIMPLE_TYPES
 
 
 def b2a(s):
-    '''Encode a value as a cookie- and url-safe string.
+    '''Encode a bytes/string as a cookie- and url-safe string.
 
     Encoded string use only alpahnumeric characters, and "._-".
     '''
-    text = str(s).translate(a2u_map)
-    if six.PY3:
-        text = text.encode('utf-8')
-    return base64.b64encode(text)
+    if not isinstance(s, bytes):
+        s = str(s)
+        if isinstance(s, six.text_type):
+            s = s.encode('utf-8')
+    return base64.urlsafe_b64encode(s)
 
 
 def a2b(s):
-    '''Decode a b2a-encoded string.'''
-    return base64.b64decode(s.translate(u2a_map))
+    '''Decode a b2a-encoded value to bytes.'''
+    if not isinstance(s, bytes):
+        if isinstance(s, six.text_type):
+            s = s.encode('ascii')
+    return base64.urlsafe_b64decode(s)
 
 
 def encodeExpansion(nodes, compress=1):
-    '''Encode the expanded node ids of a tree into a string.
+    '''Encode the expanded node ids of a tree into bytes.
 
     Accepts a list of nodes, such as that produced by root.flat().
     Marks each expanded node with an expansion_number attribute.
@@ -267,34 +263,32 @@ def encodeExpansion(nodes, compress=1):
     '''
     steps = []
     last_depth = -1
-    n = 0
-    for node in nodes:
+    for n, node in enumerate(nodes):
         if node.state <= 0:
             continue
         dd = last_depth - node.depth + 1
         last_depth = node.depth
         if dd > 0:
             steps.append('_' * dd)
-        steps.append(node.id)
+        steps.append(node.id) # id is bytes
         node.expansion_number = n
-        n = n + 1
-    result = ':'.join(steps)
+    result = b':'.join(steps)
     if compress and len(result) > 2:
-        zresult = ':' + b2a(zlib.compress(result, 9))
+        zresult = b':' + b2a(zlib.compress(result, 9))
         if len(zresult) < len(result):
             result = zresult
     return result
 
 
 def decodeExpansion(s, nth=None, maxsize=8192):
-    '''Decode an expanded node map from a string.
+    '''Decode an expanded node map from bytes.
 
     If nth is an integer, also return the (map, key) pair for the nth entry.
     '''
     if len(s) > maxsize:  # Set limit to avoid DoS attacks.
         raise ValueError('Encoded node map too large')
 
-    if s[0] == ':':  # Compressed state
+    if s.startswith(b':'):  # Compressed state
         dec = zlib.decompressobj()
         s = dec.decompress(a2b(s[1:]), maxsize)
         if dec.unconsumed_tail:
@@ -308,8 +302,8 @@ def decodeExpansion(s, nth=None, maxsize=8192):
     if nth is not None:
         nth_pair = (None, None)
     obid = None
-    for step in s.split(':'):
-        if step.startswith('_'):
+    for step in s.split(b':'):
+        if step.startswith(b'_'):
             pop = len(step) - 1
             continue
         if pop < 0: