Edit File: __diff.py
#!/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 """ Module to show if an object has changed since it was memorised """ import builtins import os import sys import types try: import numpy HAS_NUMPY = True except ImportError: HAS_NUMPY = False # pypy doesn't use reference counting getrefcount = getattr(sys, 'getrefcount', lambda x:0) # memo of objects indexed by id to a tuple (attributes, sequence items) # attributes is a dict indexed by attribute name to attribute id # sequence items is either a list of ids, of a dictionary of keys to ids memo = {} id_to_obj = {} # types that cannot have changing attributes builtins_types = set((str, list, dict, set, frozenset, int)) dont_memo = set(id(i) for i in (memo, sys.modules, sys.path_importer_cache, os.environ, id_to_obj)) def get_attrs(obj): """ Gets all the attributes of an object though its __dict__ or return None """ if type(obj) in builtins_types \ or type(obj) is type and obj in builtins_types: return return getattr(obj, '__dict__', None) def get_seq(obj, cache={str: False, frozenset: False, list: True, set: True, dict: True, tuple: True, type: False, types.ModuleType: False, types.FunctionType: False, types.BuiltinFunctionType: False}): """ Gets all the items in a sequence or return None """ try: o_type = obj.__class__ except AttributeError: o_type = type(obj) hsattr = hasattr if o_type in cache: if cache[o_type]: if hsattr(obj, "copy"): return obj.copy() return obj elif HAS_NUMPY and o_type in (numpy.ndarray, numpy.ma.core.MaskedConstant): if obj.shape and obj.size: return obj else: return [] elif hsattr(obj, "__contains__") and hsattr(obj, "__iter__") \ and hsattr(obj, "__len__") and hsattr(o_type, "__contains__") \ and hsattr(o_type, "__iter__") and hsattr(o_type, "__len__"): cache[o_type] = True if hsattr(obj, "copy"): return obj.copy() return obj else: cache[o_type] = False return None def memorise(obj, force=False): """ Adds an object to the memo, and recursively adds all the objects attributes, and if it is a container, its items. Use force=True to update an object already in the memo. Updating is not recursively done. """ obj_id = id(obj) if obj_id in memo and not force or obj_id in dont_memo: return id_ = id g = get_attrs(obj) if g is None: attrs_id = None else: attrs_id = dict((key,id_(value)) for key, value in g.items()) s = get_seq(obj) if s is None: seq_id = None elif hasattr(s, "items"): seq_id = dict((id_(key),id_(value)) for key, value in s.items()) elif not hasattr(s, "__len__"): #XXX: avoid TypeError from unexpected case seq_id = None else: seq_id = [id_(i) for i in s] memo[obj_id] = attrs_id, seq_id id_to_obj[obj_id] = obj mem = memorise if g is not None: [mem(value) for key, value in g.items()] if s is not None: if hasattr(s, "items"): [(mem(key), mem(item)) for key, item in s.items()] else: if hasattr(s, '__len__'): [mem(item) for item in s] else: mem(s) def release_gone(): itop, mp, src = id_to_obj.pop, memo.pop, getrefcount [(itop(id_), mp(id_)) for id_, obj in list(id_to_obj.items()) if src(obj) < 4] #XXX: correct for pypy? def whats_changed(obj, seen=None, simple=False, first=True): """ Check an object against the memo. Returns a list in the form (attribute changes, container changed). Attribute changes is a dict of attribute name to attribute value. container changed is a boolean. If simple is true, just returns a boolean. None for either item means that it has not been checked yet """ # Special cases if first: # ignore the _ variable, which only appears in interactive sessions if "_" in builtins.__dict__: del builtins._ if seen is None: seen = {} obj_id = id(obj) if obj_id in seen: if simple: return any(seen[obj_id]) return seen[obj_id] # Safety checks if obj_id in dont_memo: seen[obj_id] = [{}, False] if simple: return False return seen[obj_id] elif obj_id not in memo: if simple: return True else: raise RuntimeError("Object not memorised " + str(obj)) seen[obj_id] = ({}, False) chngd = whats_changed id_ = id # compare attributes attrs = get_attrs(obj) if attrs is None: changed = {} else: obj_attrs = memo[obj_id][0] obj_get = obj_attrs.get changed = dict((key,None) for key in obj_attrs if key not in attrs) for key, o in attrs.items(): if id_(o) != obj_get(key, None) or chngd(o, seen, True, False): changed[key] = o # compare sequence items = get_seq(obj) seq_diff = False if (items is not None) and (hasattr(items, '__len__')): obj_seq = memo[obj_id][1] if (len(items) != len(obj_seq)): seq_diff = True elif hasattr(obj, "items"): # dict type obj obj_get = obj_seq.get for key, item in items.items(): if id_(item) != obj_get(id_(key)) \ or chngd(key, seen, True, False) \ or chngd(item, seen, True, False): seq_diff = True break else: for i, j in zip(items, obj_seq): # list type obj if id_(i) != j or chngd(i, seen, True, False): seq_diff = True break seen[obj_id] = changed, seq_diff if simple: return changed or seq_diff return changed, seq_diff def has_changed(*args, **kwds): kwds['simple'] = True # ignore simple if passed in return whats_changed(*args, **kwds) __import__ = __import__ def _imp(*args, **kwds): """ Replaces the default __import__, to allow a module to be memorised before the user can change it """ before = set(sys.modules.keys()) mod = __import__(*args, **kwds) after = set(sys.modules.keys()).difference(before) for m in after: memorise(sys.modules[m]) return mod builtins.__import__ = _imp if hasattr(builtins, "_"): del builtins._ # memorise all already imported modules. This implies that this must be # imported first for any changes to be recorded for mod in list(sys.modules.values()): memorise(mod) release_gone()