#!/usr/bin/env python # # Author: Mike McKerns (mmckerns @caltech and @uqfoundation) # Copyright (c) 2008-2016 California Institute of Technology. # Copyright (c) 2016-2023 The Uncertainty Quantification Foundation. # License: 3-clause BSD. The full license text is available at: # - https://github.com/uqfoundation/dill/blob/master/LICENSE __all__ = ['parent', 'reference', 'at', 'parents', 'children'] import gc import sys from ._dill import _proxy_helper as reference from ._dill import _locate_object as at def parent(obj, objtype, ignore=()): """ >>> listiter = iter([4,5,6,7]) >>> obj = parent(listiter, list) >>> obj == [4,5,6,7] # actually 'is', but don't have handle any longer True NOTE: objtype can be a single type (e.g. int or list) or a tuple of types. WARNING: if obj is a sequence (e.g. list), may produce unexpected results. Parent finds *one* parent (e.g. the last member of the sequence). """ depth = 1 #XXX: always looking for the parent (only, right?) chain = parents(obj, objtype, depth, ignore) parent = chain.pop() if parent is obj: return None return parent def parents(obj, objtype, depth=1, ignore=()): #XXX: objtype=object ? """Find the chain of referents for obj. Chain will end with obj. objtype: an object type or tuple of types to search for depth: search depth (e.g. depth=2 is 'grandparents') ignore: an object or tuple of objects to ignore in the search """ edge_func = gc.get_referents # looking for refs, not back_refs predicate = lambda x: isinstance(x, objtype) # looking for parent type #if objtype is None: predicate = lambda x: True #XXX: in obj.mro() ? ignore = (ignore,) if not hasattr(ignore, '__len__') else ignore ignore = (id(obj) for obj in ignore) chain = find_chain(obj, predicate, edge_func, depth)[::-1] #XXX: should pop off obj... ? return chain def children(obj, objtype, depth=1, ignore=()): #XXX: objtype=object ? """Find the chain of referrers for obj. Chain will start with obj. objtype: an object type or tuple of types to search for depth: search depth (e.g. depth=2 is 'grandchildren') ignore: an object or tuple of objects to ignore in the search NOTE: a common thing to ignore is all globals, 'ignore=(globals(),)' NOTE: repeated calls may yield different results, as python stores the last value in the special variable '_'; thus, it is often good to execute something to replace '_' (e.g. >>> 1+1). """ edge_func = gc.get_referrers # looking for back_refs, not refs predicate = lambda x: isinstance(x, objtype) # looking for child type #if objtype is None: predicate = lambda x: True #XXX: in obj.mro() ? ignore = (ignore,) if not hasattr(ignore, '__len__') else ignore ignore = (id(obj) for obj in ignore) chain = find_chain(obj, predicate, edge_func, depth, ignore) #XXX: should pop off obj... ? return chain # more generic helper function (cut-n-paste from objgraph) # Source at http://mg.pov.lt/objgraph/ # Copyright (c) 2008-2010 Marius Gedminas <marius@pov.lt> # Copyright (c) 2010 Stefano Rivera <stefano@rivera.za.net> # Released under the MIT licence (see objgraph/objgrah.py) def find_chain(obj, predicate, edge_func, max_depth=20, extra_ignore=()): queue = [obj] depth = {id(obj): 0} parent = {id(obj): None} ignore = set(extra_ignore) ignore.add(id(extra_ignore)) ignore.add(id(queue)) ignore.add(id(depth)) ignore.add(id(parent)) ignore.add(id(ignore)) ignore.add(id(sys._getframe())) # this function ignore.add(id(sys._getframe(1))) # find_chain/find_backref_chain, likely gc.collect() while queue: target = queue.pop(0) if predicate(target): chain = [target] while parent[id(target)] is not None: target = parent[id(target)] chain.append(target) return chain tdepth = depth[id(target)] if tdepth < max_depth: referrers = edge_func(target) ignore.add(id(referrers)) for source in referrers: if id(source) in ignore: continue if id(source) not in depth: depth[id(source)] = tdepth + 1 parent[id(source)] = target queue.append(source) return [obj] # not found # backward compatibility refobject = at # EOF