JezK
Edit File: objectpath.pxi
################################################################################ # ObjectPath ctypedef struct _ObjectPath: const_xmlChar* href const_xmlChar* name Py_ssize_t index cdef object _NO_DEFAULT = object() cdef class ObjectPath: u"""ObjectPath(path) Immutable object that represents a compiled object path. Example for a path: 'root.child[1].{other}child[25]' """ cdef readonly object find cdef list _path cdef object _path_str cdef _ObjectPath* _c_path cdef Py_ssize_t _path_len def __init__(self, path): if python._isString(path): self._path = _parse_object_path_string(path) self._path_str = path else: self._path = _parse_object_path_list(path) self._path_str = u'.'.join(path) self._path_len = len(self._path) self._c_path = _build_object_path_segments(self._path) self.find = self.__call__ def __dealloc__(self): if self._c_path is not NULL: python.lxml_free(self._c_path) def __str__(self): return self._path_str def __call__(self, _Element root not None, *_default): u"""Follow the attribute path in the object structure and return the target attribute value. If it it not found, either returns a default value (if one was passed as second argument) or raises AttributeError. """ if _default: if len(_default) > 1: raise TypeError, u"invalid number of arguments: needs one or two" default = _default[0] else: default = _NO_DEFAULT return _find_object_path(root, self._c_path, self._path_len, default) def hasattr(self, _Element root not None): u"hasattr(self, root)" try: _find_object_path(root, self._c_path, self._path_len, _NO_DEFAULT) except AttributeError: return False return True def setattr(self, _Element root not None, value): u"""setattr(self, root, value) Set the value of the target element in a subtree. If any of the children on the path does not exist, it is created. """ _create_object_path(root, self._c_path, self._path_len, 1, value) def addattr(self, _Element root not None, value): u"""addattr(self, root, value) Append a value to the target element in a subtree. If any of the children on the path does not exist, it is created. """ _create_object_path(root, self._c_path, self._path_len, 0, value) cdef object __MATCH_PATH_SEGMENT = re.compile( ur"(\.?)\s*(?:\{([^}]*)\})?\s*([^.{}\[\]\s]+)\s*(?:\[\s*([-0-9]+)\s*\])?", re.U).match cdef tuple _RELATIVE_PATH_SEGMENT = (None, None, 0) cdef list _parse_object_path_string(_path): u"""Parse object path string into a (ns, name, index) list. """ cdef bint has_dot cdef unicode path new_path = [] if isinstance(_path, bytes): path = (<bytes>_path).decode('ascii') elif type(_path) is not unicode: path = unicode(_path) else: path = _path path = path.strip() if path == u'.': return [_RELATIVE_PATH_SEGMENT] path_pos = 0 while path: match = __MATCH_PATH_SEGMENT(path, path_pos) if match is None: break dot, ns, name, index = match.groups() index = int(index) if index else 0 has_dot = dot == u'.' if not new_path: if has_dot: # path '.child' => ignore root new_path.append(_RELATIVE_PATH_SEGMENT) elif index: raise ValueError, u"index not allowed on root node" elif not has_dot: raise ValueError, u"invalid path" if ns is not None: ns = python.PyUnicode_AsUTF8String(ns) name = python.PyUnicode_AsUTF8String(name) new_path.append( (ns, name, index) ) path_pos = match.end() if not new_path or len(path) > path_pos: raise ValueError, u"invalid path" return new_path cdef list _parse_object_path_list(path): u"""Parse object path sequence into a (ns, name, index) list. """ new_path = [] for item in path: item = item.strip() if not new_path and item == u'': # path '.child' => ignore root ns = name = None index = 0 else: ns, name = cetree.getNsTag(item) c_name = _xcstr(name) index_pos = tree.xmlStrchr(c_name, c'[') if index_pos is NULL: index = 0 else: index_end = tree.xmlStrchr(index_pos + 1, c']') if index_end is NULL: raise ValueError, u"index must be enclosed in []" index = int(index_pos[1:index_end - index_pos]) if not new_path and index != 0: raise ValueError, u"index not allowed on root node" name = <bytes>c_name[:index_pos - c_name] new_path.append( (ns, name, index) ) if not new_path: raise ValueError, u"invalid path" return new_path cdef _ObjectPath* _build_object_path_segments(list path_list) except NULL: cdef _ObjectPath* c_path cdef _ObjectPath* c_path_segments c_path_segments = <_ObjectPath*>python.lxml_malloc(len(path_list), sizeof(_ObjectPath)) if c_path_segments is NULL: raise MemoryError() c_path = c_path_segments for href, name, index in path_list: c_path[0].href = _xcstr(href) if href is not None else NULL c_path[0].name = _xcstr(name) if name is not None else NULL c_path[0].index = index c_path += 1 return c_path_segments cdef _find_object_path(_Element root, _ObjectPath* c_path, Py_ssize_t c_path_len, default_value): u"""Follow the path to find the target element. """ cdef tree.xmlNode* c_node cdef Py_ssize_t c_index c_node = root._c_node c_name = c_path[0].name c_href = c_path[0].href if c_href is NULL or c_href[0] == c'\0': c_href = tree._getNs(c_node) if not cetree.tagMatches(c_node, c_href, c_name): if default_value is not _NO_DEFAULT: return default_value else: raise ValueError( f"root element does not match: need {cetree.namespacedNameFromNsName(c_href, c_name)}, got {root.tag}") while c_node is not NULL: c_path_len -= 1 if c_path_len <= 0: break c_path += 1 if c_path[0].href is not NULL: c_href = c_path[0].href # otherwise: keep parent namespace c_name = tree.xmlDictExists(c_node.doc.dict, c_path[0].name, -1) if c_name is NULL: c_name = c_path[0].name c_node = NULL break c_index = c_path[0].index c_node = c_node.last if c_index < 0 else c_node.children c_node = _findFollowingSibling(c_node, c_href, c_name, c_index) if c_node is not NULL: return cetree.elementFactory(root._doc, c_node) elif default_value is not _NO_DEFAULT: return default_value else: tag = cetree.namespacedNameFromNsName(c_href, c_name) raise AttributeError, f"no such child: {tag}" cdef _create_object_path(_Element root, _ObjectPath* c_path, Py_ssize_t c_path_len, int replace, value): u"""Follow the path to find the target element, build the missing children as needed and set the target element to 'value'. If replace is true, an existing value is replaced, otherwise the new value is added. """ cdef _Element child cdef tree.xmlNode* c_node cdef tree.xmlNode* c_child cdef Py_ssize_t c_index if c_path_len == 1: raise TypeError, u"cannot update root node" c_node = root._c_node c_name = c_path[0].name c_href = c_path[0].href if c_href is NULL or c_href[0] == c'\0': c_href = tree._getNs(c_node) if not cetree.tagMatches(c_node, c_href, c_name): raise ValueError( f"root element does not match: need {cetree.namespacedNameFromNsName(c_href, c_name)}, got {root.tag}") while c_path_len > 1: c_path_len -= 1 c_path += 1 if c_path[0].href is not NULL: c_href = c_path[0].href # otherwise: keep parent namespace c_index = c_path[0].index c_name = tree.xmlDictExists(c_node.doc.dict, c_path[0].name, -1) if c_name is NULL: c_name = c_path[0].name c_child = NULL else: c_child = c_node.last if c_index < 0 else c_node.children c_child = _findFollowingSibling(c_child, c_href, c_name, c_index) if c_child is not NULL: c_node = c_child elif c_index != 0: raise TypeError, u"creating indexed path attributes is not supported" elif c_path_len == 1: _appendValue(cetree.elementFactory(root._doc, c_node), cetree.namespacedNameFromNsName(c_href, c_name), value) return else: child = cetree.makeSubElement( cetree.elementFactory(root._doc, c_node), cetree.namespacedNameFromNsName(c_href, c_name), None, None, None, None) c_node = child._c_node # if we get here, the entire path was already there if replace: element = cetree.elementFactory(root._doc, c_node) _replaceElement(element, value) else: _appendValue(cetree.elementFactory(root._doc, c_node.parent), cetree.namespacedName(c_node), value) cdef list _build_descendant_paths(tree.xmlNode* c_node, prefix_string): u"""Returns a list of all descendant paths. """ cdef list path, path_list tag = cetree.namespacedName(c_node) if prefix_string: if prefix_string[-1] != u'.': prefix_string += u'.' prefix_string = prefix_string + tag else: prefix_string = tag path = [prefix_string] path_list = [] _recursive_build_descendant_paths(c_node, path, path_list) return path_list cdef int _recursive_build_descendant_paths(tree.xmlNode* c_node, list path, list path_list) except -1: u"""Fills the list 'path_list' with all descendant paths, initial prefix being in the list 'path'. """ cdef tree.xmlNode* c_child tags = {} path_list.append(u'.'.join(path)) c_href = tree._getNs(c_node) c_child = c_node.children while c_child is not NULL: while c_child.type != tree.XML_ELEMENT_NODE: c_child = c_child.next if c_child is NULL: return 0 if c_href is tree._getNs(c_child): tag = pyunicode(c_child.name) elif c_href is not NULL and tree._getNs(c_child) is NULL: # special case: parent has namespace, child does not tag = u'{}' + pyunicode(c_child.name) else: tag = cetree.namespacedName(c_child) count = tags.get(tag) if count is None: tags[tag] = 1 else: tags[tag] = count + 1 tag += f'[{count}]' path.append(tag) _recursive_build_descendant_paths(c_child, path, path_list) del path[-1] c_child = c_child.next return 0