+class Visitor:
+
+ def __init__(self):
+ self.dispatch = {}
+ self.dispatch[type(None)] = self.visitNone
+ self.dispatch[bool] = self.visitBool
+ self.dispatch[int] = self.visitInt
+ self.dispatch[long] = self.visitInt
+ self.dispatch[float] = self.visitFloat
+ self.dispatch[str] = self.visitStr
+ self.dispatch[tuple] = self.visitTuple
+ self.dispatch[list] = self.visitList
+ self.dispatch[dict] = self.visitDict
+ self.dispatch[bytearray] = self.visitByteArray
+
+ def visit(self, obj):
+ method = self.dispatch.get(type(obj), self.visitObj)
+ return method(obj)
+
+ def visitObj(self, obj):
+ raise NotImplementedError
+
+ def visitAtom(self, obj):
+ return self.visitObj(obj)
+
+ def visitNone(self, obj):
+ return self.visitAtom(obj)
+
+ def visitBool(self, obj):
+ return self.visitAtom(obj)
+
+ def visitInt(self, obj):
+ return self.visitAtom(obj)
+
+ def visitFloat(self, obj):
+ return self.visitAtom(obj)
+
+ def visitStr(self, obj):
+ return self.visitAtom(obj)
+
+ def visitIterable(self, obj):
+ return self.visitObj(obj)
+
+ def visitTuple(self, obj):
+ return self.visitIterable(obj)
+
+ def visitList(self, obj):
+ return self.visitIterable(obj)
+
+ def visitDict(self, obj):
+ raise NotImplementedError
+
+ def visitByteArray(self, obj):
+ raise NotImplementedError
+
+
+class Dumper(Visitor):
+
+ id_re = re.compile('^[_A-Za-z][_A-Za-z0-9]*$')
+
+ def visitObj(self, obj):
+ return repr(obj)
+
+ def visitStr(self, obj):
+ if self.id_re.match(obj):
+ return obj
+ else:
+ return repr(obj)
+
+ def visitTuple(self, obj):
+ return '[' + ', '.join(itertools.imap(self.visit, obj)) + ']'
+
+ def visitList(self, obj):
+ return '(' + ', '.join(itertools.imap(self.visit, obj)) + ')'
+
+ def visitByteArray(self, obj):
+ return 'blob(%u)' % len(obj)
+
+
+class Hasher(Visitor):
+ '''Returns a hashable version of the objtree.'''
+
+ def visitObj(self, obj):
+ return obj
+
+ def visitAtom(self, obj):
+ return obj
+
+ def visitIterable(self, obj):
+ return tuple(itertools.imap(self.visit, obj))
+
+ def visitByteArray(self, obj):
+ return str(obj)
+
+
+class Rebuilder(Visitor):
+ '''Returns a hashable version of the objtree.'''
+
+ def visitAtom(self, obj):
+ return obj
+
+ def visitIterable(self, obj):
+ changed = False
+ newItems = []
+ for oldItem in obj:
+ newItem = self.visit(oldItem)
+ if newItem is not oldItem:
+ changed = True
+ newItems.append(newItem)
+ if changed:
+ klass = type(obj)
+ return klass(newItems)
+ else:
+ return obj
+
+ def visitByteArray(self, obj):
+ return obj
+
+
+class Call:
+
+ def __init__(self, callTuple):
+ self.no, self.functionName, self.args, self.ret = callTuple
+ self._hash = None
+
+ def __str__(self):
+ s = self.functionName
+ if self.no is not None:
+ s = str(self.no) + ' ' + s
+ dumper = Dumper()
+ s += '(' + ', '.join(itertools.imap(dumper.visit, self.args)) + ')'
+ if self.ret is not None:
+ s += ' = '
+ s += dumper.visit(self.ret)
+ return s
+
+ def __eq__(self, other):
+ return \
+ self.functionName == other.functionName and \
+ self.args == other.args and \
+ self.ret == other.ret
+
+ def __hash__(self):
+ if self._hash is None:
+ hasher = Hasher()
+ hashable = hasher.visit(self.functionName), hasher.visit(self.args), hasher.visit(self.ret)
+ self._hash = hash(hashable)
+ return self._hash
+
+
+class Unpickler:
+
+ callFactory = Call
+
+ def __init__(self, stream):
+ self.stream = stream
+
+ def parse(self):
+ while self.parseCall():
+ pass
+
+ def parseCall(self):