U
    }®c…0  ã                   @   sô   d Z ddlZddlZddlZddlZddlmZ ddlmZm	Z	 ddl
mZ ddlmZ ddlmZ edd	ƒZG d
d„ deƒZG dd„ deed�Zdd„ ZG dd„ dejƒZG dd„ dƒZG dd„ dƒZd dd„Zdd„ Zdd„ ZG dd„ dƒZdS )!zî
Various data structures used in query construction.

Factored out from django.db.models.query to avoid making the main module very
large and/or so that they can be used by other modules without getting into
circular import difficulties.
é    N)Ú
namedtuple©ÚFieldDoesNotExistÚ
FieldError)Ú
LOOKUP_SEP)Útree)ÚRemovedInDjango40WarningÚPathInfozGfrom_opts to_opts target_fields join_field m2m direct filtered_relationc                       s<   e Zd Zedd„ ƒZdd„ Z‡ fdd„Z‡ fdd„Z‡  ZS )	ÚInvalidQueryTypec                 C   s   t tfS ©Nr   ©Úself© r   ú@/tmp/pip-unpacked-wheel-7m9rsep5/django/db/models/query_utils.pyÚ_subclasses   s    zInvalidQueryType._subclassesc                 C   s   t jdtdd� d S )Nz\The InvalidQuery exception class is deprecated. Use FieldDoesNotExist or FieldError instead.é   )ÚcategoryÚ
stacklevel)ÚwarningsÚwarnr   r   r   r   r   Z__warn   s
    üzInvalidQueryType.__warnc                    s    |   ¡  t|| jƒptƒ  |¡S r   )Ú_InvalidQueryType__warnÚ
isinstancer   ÚsuperÚ__instancecheck__)r   Úinstance©Ú	__class__r   r   r   &   s    z"InvalidQueryType.__instancecheck__c                    s    |   ¡  t|| jƒptƒ  |¡S r   )r   Ú
issubclassr   r   Ú__subclasscheck__)r   Úsubclassr   r   r   r   *   s    z"InvalidQueryType.__subclasscheck__)	Ú__name__Ú
__module__Ú__qualname__Úpropertyr   r   r   r   Ú__classcell__r   r   r   r   r
      s
   
r
   c                   @   s   e Zd ZdS )ÚInvalidQueryN)r    r!   r"   r   r   r   r   r%   /   s   r%   )Ú	metaclassc                 c   s&   | V  |   ¡ D ]}t|ƒE d H  qd S r   )Ú__subclasses__Ú
subclasses©Úclsr   r   r   r   r(   3   s    r(   c                       sj   e Zd ZdZdZdZeZdZdddœ‡ fdd	„
Zd
d„ Z	dd„ Z
dd„ Zdd„ Zddd„Zdd„ Z‡  ZS )ÚQze
    Encapsulate filters as objects that can then be combined logically (using
    `&` and `|`).
    ÚANDÚORTNF)Ú
_connectorÚ_negatedc                   s"   t ƒ j|t| ¡ ƒ•||d� d S )N)ÚchildrenÚ	connectorÚnegated)r   Ú__init__ÚsortedÚitems)r   r.   r/   ÚargsÚkwargsr   r   r   r3   D   s    z
Q.__init__c                 C   s˜   t |tƒs"t|ddƒdks"t|ƒ‚| sBt|dƒr8| ¡ S t |¡S t |tƒrl|sl|  ¡ \}}}t| ƒ||ŽS t| ƒƒ }||_| 	| |¡ | 	||¡ |S )NÚconditionalFTÚcopy)
r   r+   ÚgetattrÚ	TypeErrorÚhasattrr9   ÚdeconstructÚtyper1   Úadd)r   ÚotherÚconnÚ_r6   r7   Úobjr   r   r   Ú_combineG   s    
z
Q._combinec                 C   s   |   || j¡S r   )rD   r-   ©r   r@   r   r   r   Ú__or__W   s    zQ.__or__c                 C   s   |   || j¡S r   )rD   r,   rE   r   r   r   Ú__and__Z   s    z	Q.__and__c                 C   s$   t | ƒƒ }| | | j¡ | ¡  |S r   )r>   r?   r,   Únegate)r   rC   r   r   r   Ú
__invert__]   s    
zQ.__invert__c                 C   s&   |j | ||ddd�\}}| |¡ |S )NF)Úallow_joinsZ
split_subqZcheck_filterable)Z_add_qZpromote_joins)r   ÚqueryrJ   ÚreuseZ	summarizeZfor_saveZclauseZjoinsr   r   r   Úresolve_expressionc   s       þ

zQ.resolve_expressionc                 C   sf   d| j j| j jf }| d¡r*| dd¡}t| jƒ}i }| j| jkrN| j|d< | j	r\d|d< |||fS )Nz%s.%szdjango.db.models.query_utilszdjango.db.modelsr.   Tr/   )
r   r!   r    Ú
startswithÚreplaceÚtupler0   r1   Údefaultr2   )r   Úpathr6   r7   r   r   r   r=   m   s    


zQ.deconstruct)NTNFF)r    r!   r"   Ú__doc__r,   r-   rQ   r8   r3   rD   rF   rG   rI   rM   r=   r$   r   r   r   r   r+   9   s   

r+   c                   @   s*   e Zd ZdZdd„ Zd	dd„Zdd„ ZdS )
ÚDeferredAttributez„
    A wrapper for a deferred-loading field. When the value is read from this
    object the first time, the query is executed.
    c                 C   s
   || _ d S r   )Úfield)r   rU   r   r   r   r3      s    zDeferredAttribute.__init__Nc                 C   sT   |dkr| S |j }| jj}||krL|  |¡}|dkrD|j|gd� n|||< || S )zx
        Retrieve and caches the value from the datastore on the first lookup.
        Return the cached value.
        N)Úfields)Ú__dict__rU   ÚattnameÚ_check_parent_chainZrefresh_from_db)r   r   r*   ÚdataÚ
field_nameÚvalr   r   r   Ú__get__‚   s    
zDeferredAttribute.__get__c                 C   s6   |j }| | jj¡}| jjr2| j|kr2t||jƒS dS )zÁ
        Check if the field value can be fetched from a parent field already
        loaded in the instance. This can be done if the to-be fetched
        field is a primary key field.
        N)Ú_metaZget_ancestor_linkrU   ÚmodelÚprimary_keyr:   rX   )r   r   ÚoptsZ
link_fieldr   r   r   rY   •   s
    z%DeferredAttribute._check_parent_chain)N)r    r!   r"   rS   r3   r]   rY   r   r   r   r   rT   z   s   
rT   c                   @   st   e Zd Zedd„ ƒZeejdd�dd„ ƒƒZdd„ Zd	d
„ Z	e
dd„ ƒZedd„ ƒZeddd„ƒZeddd„ƒZdS )ÚRegisterLookupMixinc                 C   s   |   ¡  |d ¡S r   )Úget_lookupsÚget)r*   Úlookup_namer   r   r   Ú_get_lookup¤   s    zRegisterLookupMixin._get_lookupN)Úmaxsizec                 C   s   dd„ t  | ¡D ƒ}|  |¡S )Nc                 S   s   g | ]}|j  d i ¡‘qS )Úclass_lookups)rW   rd   )Ú.0Úparentr   r   r   Ú
<listcomp>«   s     z3RegisterLookupMixin.get_lookups.<locals>.<listcomp>)ÚinspectÚgetmroÚmerge_dicts)r*   rh   r   r   r   rc   ¨   s    zRegisterLookupMixin.get_lookupsc                 C   sN   ddl m} |  |¡}|d kr4t| dƒr4| j |¡S |d k	rJt||ƒsJd S |S )Nr   )ÚLookupÚoutput_field)Údjango.db.models.lookupsro   rf   r<   rp   Ú
get_lookupr   )r   re   ro   Úfoundr   r   r   rr   ®   s    
zRegisterLookupMixin.get_lookupc                 C   sN   ddl m} |  |¡}|d kr4t| dƒr4| j |¡S |d k	rJt||ƒsJd S |S )Nr   )Ú	Transformrp   )rq   rt   rf   r<   rp   Úget_transformr   )r   re   rt   rs   r   r   r   ru   ·   s    
z!RegisterLookupMixin.get_transformc                 C   s    i }t | ƒD ]}| |¡ q|S )z«
        Merge dicts in reverse to preference the order of the original list. e.g.,
        merge_dicts([a, b]) will preference the keys in 'a' over those in 'b'.
        )ÚreversedÚupdate)ZdictsÚmergedÚdr   r   r   rn   À   s    zRegisterLookupMixin.merge_dictsc                 C   s   t | ƒD ]}|j ¡  qd S r   )r(   rc   Úcache_clearr)   r   r   r   Ú_clear_cached_lookupsË   s    z)RegisterLookupMixin._clear_cached_lookupsc                 C   s4   |d kr|j }d| jkri | _|| j|< |  ¡  |S )Nrh   )re   rW   rh   r{   ©r*   Úlookupre   r   r   r   Úregister_lookupÐ   s    

z#RegisterLookupMixin.register_lookupc                 C   s   |dkr|j }| j|= dS )zn
        Remove given lookup from cls lookups. For use in tests only as it's
        not thread-safe.
        N)re   rh   r|   r   r   r   Ú_unregister_lookupÚ   s    z&RegisterLookupMixin._unregister_lookup)N)N)r    r!   r"   Úclassmethodrf   Ú	functoolsÚ	lru_cacherc   rr   ru   Ústaticmethodrn   r{   r~   r   r   r   r   r   rb   ¢   s   

		


	rb   Fc                 C   sŽ   | j s
dS | j jr|sdS |rD|r2|  ¡ |kr2dS |sD| j|krDdS |sR| jrRdS |rŠ| j|krŠ|rŠ| j|krŠd| jjj| jf }t	|ƒ‚dS )au  
    Return True if this field should be used to descend deeper for
    select_related() purposes. Used by both the query construction code
    (sql.query.fill_related_selections()) and the model instance creation code
    (query.get_klass_info()).

    Arguments:
     * field - the field to be checked
     * restricted - a boolean field, indicating if the field list has been
       manually restricted using a requested clause)
     * requested - The select_related() dictionary.
     * load_fields - the set of fields to be loaded on this model
     * reverse - boolean, True if we are checking a reverse select related
    FzXField %s.%s cannot be both deferred and traversed using select_related at the same time.T)
Zremote_fieldZparent_linkZrelated_query_nameÚnameÚnullrX   r_   r^   Zobject_namer   )rU   Z
restrictedÚ	requestedZload_fieldsÚreverseÚmsgr   r   r   Úselect_related_descendå   s&    

ýr‰   c                 C   sV   t dt| ƒd ƒD ]>}t | d|… ¡}||kr|| r|| | |d… f  S qdS )zÕ
    Check if the lookup_parts contains references to the given annotations set.
    Because the LOOKUP_SEP is contained in the default annotation names, check
    each prefix of the lookup_parts for a match.
    é   r   N)Fr   )ÚrangeÚlenr   Újoin)Zlookup_partsÚannotationsÚnZlevel_n_lookupr   r   r   Úrefs_expression
  s
    r�   c                    s,   ‡ fdd„}||ƒp*t |ddƒo*||jjƒS )zÞ
    Check that self.model is compatible with target_opts. Compatibility
    is OK if:
      1) model and opts match (where proxy inheritance is removed)
      2) model is parent of opts' model or the other way around
    c                    s*   ˆ j j| jkp(| jˆ j  ¡ kp(ˆ |  ¡ kS r   )r^   Zconcrete_modelZget_parent_list)ra   ©r_   r   r   Úcheck  s
    ÿ
ýz-check_rel_lookup_compatibility.<locals>.checkr`   F)r:   r_   r^   )r_   Ztarget_optsrU   r’   r   r‘   r   Úcheck_rel_lookup_compatibility  s    þr“   c                   @   s@   e Zd ZdZeƒ dœdd„Zdd„ Zdd„ Zd	d
„ Zdd„ Z	dS )ÚFilteredRelationz7Specify custom filtering in the ON clause of SQL joins.©Ú	conditionc                C   s:   |st dƒ‚|| _d | _t|tƒs*t dƒ‚|| _g | _d S )Nzrelation_name cannot be empty.z*condition argument must be a Q() instance.)Ú
ValueErrorÚrelation_nameÚaliasr   r+   r–   rR   )r   r˜   r–   r   r   r   r3   6  s    
zFilteredRelation.__init__c                 C   s4   t || jƒstS | j|jko2| j|jko2| j|jkS r   )r   r   ÚNotImplementedr˜   r™   r–   rE   r   r   r   Ú__eq__@  s    
ÿ
ýzFilteredRelation.__eq__c                 C   s,   t | j| jd�}| j|_| jd d … |_|S )Nr•   )r”   r˜   r–   r™   rR   )r   Úcloner   r   r   rœ   I  s    zFilteredRelation.clonec                 O   s   t dƒ‚dS )zz
        QuerySet.annotate() only accepts expression-like arguments
        (with a resolve_expression() method).
        z0FilteredRelation.resolve_expression() is unused.N)ÚNotImplementedError)r   r6   r7   r   r   r   rM   O  s    z#FilteredRelation.resolve_expressionc                 C   s&   |j }|j| jt| jƒd�}| |¡S )N)rL   )rK   Zbuild_filtered_relation_qr–   ÚsetrR   Úcompile)r   ÚcompilerÚ
connectionrK   Úwherer   r   r   Úas_sqlV  s    zFilteredRelation.as_sqlN)
r    r!   r"   rS   r+   r3   r›   rœ   rM   r£   r   r   r   r   r”   3  s   
	r”   )F)rS   r9   r�   rl   r   Úcollectionsr   Zdjango.core.exceptionsr   r   Zdjango.db.models.constantsr   Zdjango.utilsr   Zdjango.utils.deprecationr   r	   r>   r
   Ú	Exceptionr%   r(   ÚNoder+   rT   rb   r‰   r�   r“   r”   r   r   r   r   Ú<module>   s(   
A(C
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