Celery Model Serializer

README.md

Usage

app = Celery('myapp')

@app.task(serializer='django-model')
def test(x):
    print x
    
obj = MyModel.objects.get(pk=12)
test.delay(obj)

django_model_serializer.py

import pickle
from kombu.serialization import register, loads, dumps, unpickle, registry
import copy
from django.db import models
from django.db.models.loading import get_model
from django.utils.encoding import force_str


class SerializedModel(object):
    app_label = None
    model = None
    pk = None

    def __init__(self, obj):
        self.app_label = obj._meta.app_label
        self.model_name = obj._meta.model_name
        self.auto_field_value = getattr(obj, obj._meta.auto_field.attname)

    def get_model_instance(self):
        model_cls = get_model(self.app_label, self.model_name)
        auto_field_attname = model_cls._meta.auto_field.attname
        auto_field_value = self.auto_field_value
        return model_cls.objects.get(**{auto_field_attname: auto_field_value})

    def __repr__(self):
        return force_str('<%s: %s.%s(%s)>' % (self.__class__.__name__,
                                              self.app_label,
                                              self.model_name,
                                              self.auto_field_value))


def model_decode(data):
    _data = unpickle(data)
    args = []
    args_has_models = False
    for obj in _data['args']:
        if isinstance(obj, SerializedModel):
            args_has_models = True
            args.append(obj.get_model_instance())
        else:
            args.append(obj)
    if args_has_models:
        _data['args'] = tuple(args)
    for kwarg, obj in _data['kwargs']:
        if isinstance(obj, SerializedModel):
            _data['kwargs'][kwarg] = obj.get_model_instance()
    return _data


def model_encode(data):
    _data = copy.copy(data)
    args = []
    args_has_models = False
    for obj in _data['args']:
        if isinstance(obj, models.Model):
            args_has_models = True
            args.append(SerializedModel(obj))
        else:
            args.append(obj)
    if args_has_models:
        _data['args'] = tuple(args)
    for kwarg, obj in _data['kwargs']:
        if isinstance(obj, models.Model):
            _data['kwargs'][kwarg] = SerializedModel(obj)
    return pickle.dumps(_data)


register('django-model', model_encode, model_decode, content_type='application/x-python-serialize', content_encoding='binary')
registry.enable('django-model')