##// END OF EJS Templates
allow async output on the most recent request...
allow async output on the most recent request Keeps track of the most recent request, so async output is still allowed

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pickleutil.py
390 lines | 10.8 KiB | text/x-python | PythonLexer
# encoding: utf-8
"""Pickle related utilities. Perhaps this should be called 'can'."""
__docformat__ = "restructuredtext en"
#-------------------------------------------------------------------------------
# Copyright (C) 2008-2011 The IPython Development Team
#
# Distributed under the terms of the BSD License. The full license is in
# the file COPYING, distributed as part of this software.
#-------------------------------------------------------------------------------
#-------------------------------------------------------------------------------
# Imports
#-------------------------------------------------------------------------------
import copy
import logging
import sys
from types import FunctionType
try:
import cPickle as pickle
except ImportError:
import pickle
from . import codeutil # This registers a hook when it's imported
from . import py3compat
from .importstring import import_item
from .py3compat import string_types, iteritems
from IPython.config import Application
if py3compat.PY3:
buffer = memoryview
class_type = type
else:
from types import ClassType
class_type = (type, ClassType)
#-------------------------------------------------------------------------------
# Functions
#-------------------------------------------------------------------------------
def use_dill():
"""use dill to expand serialization support
adds support for object methods and closures to serialization.
"""
# import dill causes most of the magic
import dill
# dill doesn't work with cPickle,
# tell the two relevant modules to use plain pickle
global pickle
pickle = dill
try:
from IPython.kernel.zmq import serialize
except ImportError:
pass
else:
serialize.pickle = dill
# disable special function handling, let dill take care of it
can_map.pop(FunctionType, None)
#-------------------------------------------------------------------------------
# Classes
#-------------------------------------------------------------------------------
class CannedObject(object):
def __init__(self, obj, keys=[], hook=None):
"""can an object for safe pickling
Parameters
==========
obj:
The object to be canned
keys: list (optional)
list of attribute names that will be explicitly canned / uncanned
hook: callable (optional)
An optional extra callable,
which can do additional processing of the uncanned object.
large data may be offloaded into the buffers list,
used for zero-copy transfers.
"""
self.keys = keys
self.obj = copy.copy(obj)
self.hook = can(hook)
for key in keys:
setattr(self.obj, key, can(getattr(obj, key)))
self.buffers = []
def get_object(self, g=None):
if g is None:
g = {}
obj = self.obj
for key in self.keys:
setattr(obj, key, uncan(getattr(obj, key), g))
if self.hook:
self.hook = uncan(self.hook, g)
self.hook(obj, g)
return self.obj
class Reference(CannedObject):
"""object for wrapping a remote reference by name."""
def __init__(self, name):
if not isinstance(name, string_types):
raise TypeError("illegal name: %r"%name)
self.name = name
self.buffers = []
def __repr__(self):
return "<Reference: %r>"%self.name
def get_object(self, g=None):
if g is None:
g = {}
return eval(self.name, g)
class CannedFunction(CannedObject):
def __init__(self, f):
self._check_type(f)
self.code = f.__code__
if f.__defaults__:
self.defaults = [ can(fd) for fd in f.__defaults__ ]
else:
self.defaults = None
self.module = f.__module__ or '__main__'
self.__name__ = f.__name__
self.buffers = []
def _check_type(self, obj):
assert isinstance(obj, FunctionType), "Not a function type"
def get_object(self, g=None):
# try to load function back into its module:
if not self.module.startswith('__'):
__import__(self.module)
g = sys.modules[self.module].__dict__
if g is None:
g = {}
if self.defaults:
defaults = tuple(uncan(cfd, g) for cfd in self.defaults)
else:
defaults = None
newFunc = FunctionType(self.code, g, self.__name__, defaults)
return newFunc
class CannedClass(CannedObject):
def __init__(self, cls):
self._check_type(cls)
self.name = cls.__name__
self.old_style = not isinstance(cls, type)
self._canned_dict = {}
for k,v in cls.__dict__.items():
if k not in ('__weakref__', '__dict__'):
self._canned_dict[k] = can(v)
if self.old_style:
mro = []
else:
mro = cls.mro()
self.parents = [ can(c) for c in mro[1:] ]
self.buffers = []
def _check_type(self, obj):
assert isinstance(obj, class_type), "Not a class type"
def get_object(self, g=None):
parents = tuple(uncan(p, g) for p in self.parents)
return type(self.name, parents, uncan_dict(self._canned_dict, g=g))
class CannedArray(CannedObject):
def __init__(self, obj):
from numpy import ascontiguousarray
self.shape = obj.shape
self.dtype = obj.dtype.descr if obj.dtype.fields else obj.dtype.str
self.pickled = False
if sum(obj.shape) == 0:
self.pickled = True
elif obj.dtype == 'O':
# can't handle object dtype with buffer approach
self.pickled = True
elif obj.dtype.fields and any(dt == 'O' for dt,sz in obj.dtype.fields.values()):
self.pickled = True
if self.pickled:
# just pickle it
self.buffers = [pickle.dumps(obj, -1)]
else:
# ensure contiguous
obj = ascontiguousarray(obj, dtype=None)
self.buffers = [buffer(obj)]
def get_object(self, g=None):
from numpy import frombuffer
data = self.buffers[0]
if self.pickled:
# no shape, we just pickled it
return pickle.loads(data)
else:
return frombuffer(data, dtype=self.dtype).reshape(self.shape)
class CannedBytes(CannedObject):
wrap = bytes
def __init__(self, obj):
self.buffers = [obj]
def get_object(self, g=None):
data = self.buffers[0]
return self.wrap(data)
def CannedBuffer(CannedBytes):
wrap = buffer
#-------------------------------------------------------------------------------
# Functions
#-------------------------------------------------------------------------------
def _logger():
"""get the logger for the current Application
the root logger will be used if no Application is running
"""
if Application.initialized():
logger = Application.instance().log
else:
logger = logging.getLogger()
if not logger.handlers:
logging.basicConfig()
return logger
def _import_mapping(mapping, original=None):
"""import any string-keys in a type mapping
"""
log = _logger()
log.debug("Importing canning map")
for key,value in list(mapping.items()):
if isinstance(key, string_types):
try:
cls = import_item(key)
except Exception:
if original and key not in original:
# only message on user-added classes
log.error("canning class not importable: %r", key, exc_info=True)
mapping.pop(key)
else:
mapping[cls] = mapping.pop(key)
def istype(obj, check):
"""like isinstance(obj, check), but strict
This won't catch subclasses.
"""
if isinstance(check, tuple):
for cls in check:
if type(obj) is cls:
return True
return False
else:
return type(obj) is check
def can(obj):
"""prepare an object for pickling"""
import_needed = False
for cls,canner in iteritems(can_map):
if isinstance(cls, string_types):
import_needed = True
break
elif istype(obj, cls):
return canner(obj)
if import_needed:
# perform can_map imports, then try again
# this will usually only happen once
_import_mapping(can_map, _original_can_map)
return can(obj)
return obj
def can_class(obj):
if isinstance(obj, class_type) and obj.__module__ == '__main__':
return CannedClass(obj)
else:
return obj
def can_dict(obj):
"""can the *values* of a dict"""
if istype(obj, dict):
newobj = {}
for k, v in iteritems(obj):
newobj[k] = can(v)
return newobj
else:
return obj
sequence_types = (list, tuple, set)
def can_sequence(obj):
"""can the elements of a sequence"""
if istype(obj, sequence_types):
t = type(obj)
return t([can(i) for i in obj])
else:
return obj
def uncan(obj, g=None):
"""invert canning"""
import_needed = False
for cls,uncanner in iteritems(uncan_map):
if isinstance(cls, string_types):
import_needed = True
break
elif isinstance(obj, cls):
return uncanner(obj, g)
if import_needed:
# perform uncan_map imports, then try again
# this will usually only happen once
_import_mapping(uncan_map, _original_uncan_map)
return uncan(obj, g)
return obj
def uncan_dict(obj, g=None):
if istype(obj, dict):
newobj = {}
for k, v in iteritems(obj):
newobj[k] = uncan(v,g)
return newobj
else:
return obj
def uncan_sequence(obj, g=None):
if istype(obj, sequence_types):
t = type(obj)
return t([uncan(i,g) for i in obj])
else:
return obj
def _uncan_dependent_hook(dep, g=None):
dep.check_dependency()
def can_dependent(obj):
return CannedObject(obj, keys=('f', 'df'), hook=_uncan_dependent_hook)
#-------------------------------------------------------------------------------
# API dictionaries
#-------------------------------------------------------------------------------
# These dicts can be extended for custom serialization of new objects
can_map = {
'IPython.parallel.dependent' : can_dependent,
'numpy.ndarray' : CannedArray,
FunctionType : CannedFunction,
bytes : CannedBytes,
buffer : CannedBuffer,
class_type : can_class,
}
uncan_map = {
CannedObject : lambda obj, g: obj.get_object(g),
}
# for use in _import_mapping:
_original_can_map = can_map.copy()
_original_uncan_map = uncan_map.copy()