77 lines
2.4 KiB
Python
77 lines
2.4 KiB
Python
from django.db import models
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from django.contrib.contenttypes.fields import GenericRelation
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from asgiref.sync import sync_to_async
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from asyncron.utils import rgetattr
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import asyncio
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class AsyncronQuerySet( models.QuerySet ):
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async def gather_method( self, method, *args, **kwargs ):
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#This functions postpones NotImplementedError(s) casued
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#by asyncron.extensions not matching, to inside asyncio.gather
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async def raise_notemp( e ): raise e
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mapping = {}
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async for instance in self:
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try:
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mapping[instance.pk] = getattr( instance, method )( *args, **kwargs )
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except NotImplementedError as e:
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mapping[instance.pk] = raise_notemp(e)
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returns = await asyncio.gather( *list(mapping.values()), return_exceptions = True )
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for index, pk in enumerate(mapping):
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mapping[pk] = returns[index]
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return mapping
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def to_json( self, *structure ):
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return [ m.fields_to_dict( *structure ) for m in self ]
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class BaseModel( models.Model ):
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objects = AsyncronQuerySet.as_manager()
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metadata = GenericRelation("asyncron.Metadata", content_type_field = 'model_type', object_id_field = 'model_id')
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async def eval_related( self, *fields ):
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if not fields:
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fields = [ f.name for f in self._meta.fields if f.is_relation ]
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#Since we're using an underscore variable
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#This next line running correctly is optional,
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#but helps reduce or eliminate 'sync_to_async' context switches.
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try: fields = [ f for f in fields if f not in self._state.fields_cache ]
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except: print("WARNING: could not check already cached relations.")
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if fields:
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await sync_to_async(lambda: [ getattr(self, f) for f in fields ])()
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_model_presentations = {}
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@classmethod
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def presentation( cls, name ):
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def attacher_decorator( f ):
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cls._model_presentations[name] = f
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return f
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return attacher_decorator
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def fields_to_dict( self, *fields, presentation_name = None ):
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"""
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To create json/dict from fields.
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"""
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if presentation_name:
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assert presentation in self._model_presentations, f"This model '{self.__class__}' does not have a '{presentation_name}' presentation!"
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fields.extend( self._model_presentations[presentation_name].fields )
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results = {}
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for f in fields:
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name, method = (f[0], f[1]) if isinstance(f, tuple) else (f, f)
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value = method(self) if callable(method) else rgetattr(self, method)
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results[name] = value() if callable(value) else value
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return results
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class Meta:
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abstract = True
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