Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/dill/pointers.py: 17%

1#!/usr/bin/env python 

2# 

3# Author: Mike McKerns (mmckerns @caltech and @uqfoundation) 

4# Copyright (c) 2008-2016 California Institute of Technology. 

5# Copyright (c) 2016-2022 The Uncertainty Quantification Foundation. 

6# License: 3-clause BSD. The full license text is available at: 

7# - https://github.com/uqfoundation/dill/blob/master/LICENSE 

8 

9__all__ = ['parent', 'reference', 'at', 'parents', 'children'] 

10 

11import gc 

12import sys 

13 

14from ._dill import _proxy_helper as reference 

15from ._dill import _locate_object as at 

16 

17def parent(obj, objtype, ignore=()): 

18 """ 

19>>> listiter = iter([4,5,6,7]) 

20>>> obj = parent(listiter, list) 

21>>> obj == [4,5,6,7] # actually 'is', but don't have handle any longer 

22True 

23 

24NOTE: objtype can be a single type (e.g. int or list) or a tuple of types. 

25 

26WARNING: if obj is a sequence (e.g. list), may produce unexpected results. 

27Parent finds *one* parent (e.g. the last member of the sequence). 

28 """ 

29 depth = 1 #XXX: always looking for the parent (only, right?) 

30 chain = parents(obj, objtype, depth, ignore) 

31 parent = chain.pop() 

32 if parent is obj: 

33 return None 

34 return parent 

35 

36 

37def parents(obj, objtype, depth=1, ignore=()): #XXX: objtype=object ? 

38 """Find the chain of referents for obj. Chain will end with obj. 

39 

40 objtype: an object type or tuple of types to search for 

41 depth: search depth (e.g. depth=2 is 'grandparents') 

42 ignore: an object or tuple of objects to ignore in the search 

43 """ 

44 edge_func = gc.get_referents # looking for refs, not back_refs 

45 predicate = lambda x: isinstance(x, objtype) # looking for parent type 

46 #if objtype is None: predicate = lambda x: True #XXX: in obj.mro() ? 

47 ignore = (ignore,) if not hasattr(ignore, '__len__') else ignore 

48 ignore = (id(obj) for obj in ignore) 

49 chain = find_chain(obj, predicate, edge_func, depth)[::-1] 

50 #XXX: should pop off obj... ? 

51 return chain 

52 

53 

54def children(obj, objtype, depth=1, ignore=()): #XXX: objtype=object ? 

55 """Find the chain of referrers for obj. Chain will start with obj. 

56 

57 objtype: an object type or tuple of types to search for 

58 depth: search depth (e.g. depth=2 is 'grandchildren') 

59 ignore: an object or tuple of objects to ignore in the search 

60 

61 NOTE: a common thing to ignore is all globals, 'ignore=(globals(),)' 

62 

63 NOTE: repeated calls may yield different results, as python stores 

64 the last value in the special variable '_'; thus, it is often good 

65 to execute something to replace '_' (e.g. >>> 1+1). 

66 """ 

67 edge_func = gc.get_referrers # looking for back_refs, not refs 

68 predicate = lambda x: isinstance(x, objtype) # looking for child type 

69 #if objtype is None: predicate = lambda x: True #XXX: in obj.mro() ? 

70 ignore = (ignore,) if not hasattr(ignore, '__len__') else ignore 

71 ignore = (id(obj) for obj in ignore) 

72 chain = find_chain(obj, predicate, edge_func, depth, ignore) 

73 #XXX: should pop off obj... ? 

74 return chain 

75 

76 

77# more generic helper function (cut-n-paste from objgraph) 

78# Source at http://mg.pov.lt/objgraph/ 

79# Copyright (c) 2008-2010 Marius Gedminas <marius@pov.lt> 

80# Copyright (c) 2010 Stefano Rivera <stefano@rivera.za.net> 

81# Released under the MIT licence (see objgraph/objgrah.py) 

82 

83def find_chain(obj, predicate, edge_func, max_depth=20, extra_ignore=()): 

84 queue = [obj] 

85 depth = {id(obj): 0} 

86 parent = {id(obj): None} 

87 ignore = set(extra_ignore) 

88 ignore.add(id(extra_ignore)) 

89 ignore.add(id(queue)) 

90 ignore.add(id(depth)) 

91 ignore.add(id(parent)) 

92 ignore.add(id(ignore)) 

93 ignore.add(id(sys._getframe())) # this function 

94 ignore.add(id(sys._getframe(1))) # find_chain/find_backref_chain, likely 

95 gc.collect() 

96 while queue: 

97 target = queue.pop(0) 

98 if predicate(target): 

99 chain = [target] 

100 while parent[id(target)] is not None: 

101 target = parent[id(target)] 

102 chain.append(target) 

103 return chain 

104 tdepth = depth[id(target)] 

105 if tdepth < max_depth: 

106 referrers = edge_func(target) 

107 ignore.add(id(referrers)) 

108 for source in referrers: 

109 if id(source) in ignore: 

110 continue 

111 if id(source) not in depth: 

112 depth[id(source)] = tdepth + 1 

113 parent[id(source)] = target 

114 queue.append(source) 

115 return [obj] # not found 

116 

117 

118# backward compatability 

119refobject = at 

120 

121 

122# EOF