Optimization Hints

graphene_django_extras/fields.py

@@ -10,12 +10,13 @@
     is_valid_django_model,
     DJANGO_FILTER_INSTALLED,
 )
+from graphql.execution.base import get_field_def
 from graphene_django_extras.settings import graphql_api_settings
 
 from graphene_django_extras.filters.filter import get_filterset_class
 from .base_types import DjangoListObjectBase
 from .paginations.pagination import BaseDjangoGraphqlPagination
-from .utils import get_extra_filters, queryset_factory, get_related_fields, find_field
+from .utils import get_extra_filters, queryset_factory, get_related_fields, find_field, get_type
 
 
 # *********************************************** #
@@ -57,7 +58,7 @@ def __init__(
         extra_filter_meta=None,
         filterset_class=None,
         *args,
-        **kwargs,
+        **kwargs
     ):
 
         if DJANGO_FILTER_INSTALLED:
@@ -129,7 +130,7 @@ def list_resolver(manager, filterset_class, filtering_args, root, info, **kwargs
                 qs = None
 
         if qs is None:
-            qs = queryset_factory(manager, info.field_asts, info.fragments, **kwargs)
+            qs = queryset_factory(manager, info, **kwargs)
             qs = filterset_class(
                 data=filter_kwargs, queryset=qs, request=info.context
             ).qs
@@ -161,7 +162,7 @@ def __init__(
         extra_filter_meta=None,
         filterset_class=None,
         *args,
-        **kwargs,
+        **kwargs
     ):
 
         _fields = _type._meta.filter_fields
@@ -219,14 +220,11 @@ def __init__(
     def model(self):
         return self.type.of_type._meta.node._meta.model
 
-    def get_queryset(self, manager, info, **kwargs):
-        return queryset_factory(manager, info.field_asts, info.fragments, **kwargs)
-
     def list_resolver(
         self, manager, filterset_class, filtering_args, root, info, **kwargs
     ):
         filter_kwargs = {k: v for k, v in kwargs.items() if k in filtering_args}
-        qs = self.get_queryset(manager, info, **kwargs)
+        qs = queryset_factory(manager, info, **kwargs)
         qs = filterset_class(data=filter_kwargs, queryset=qs, request=info.context).qs
 
         if root and is_valid_django_model(root._meta.model):
@@ -258,7 +256,7 @@ def __init__(
         extra_filter_meta=None,
         filterset_class=None,
         *args,
-        **kwargs,
+        **kwargs
     ):
 
         if DJANGO_FILTER_INSTALLED:
@@ -299,7 +297,7 @@ def list_resolver(
         self, manager, filterset_class, filtering_args, root, info, **kwargs
     ):
 
-        qs = queryset_factory(manager, info.field_asts, info.fragments, **kwargs)
+        qs = queryset_factory(manager, info, **kwargs)
 
         filter_kwargs = {k: v for k, v in kwargs.items() if k in filtering_args}
 
@@ -318,4 +316,4 @@ def get_resolver(self, parent_resolver):
             self.type._meta.model._default_manager,
             self.filterset_class,
             self.filtering_args,
-        )
+        )

graphene_django_extras/hints.py

@@ -0,0 +1,19 @@
+__all__ = ["OptimizationHints", "resolver_hints"]
+
+
+class OptimizationHints(object):
+    def __init__(self, model_field=None, select_related=None, prefetch_related=None, only=None):
+        self.model_field = model_field
+        self.prefetch_related = set(prefetch_related) if prefetch_related else set()
+        self.select_related = set(select_related) if select_related else set()
+        self.only = set(only) if only else set()
+
+
+def resolver_hints(*args, **kwargs):
+    optimization_hints = OptimizationHints(*args, **kwargs)
+
+    def apply_resolver_hints(resolver):
+        resolver.optimization_hints = optimization_hints
+        return resolver
+
+    return apply_resolver_hints

graphene_django_extras/utils.py

@@ -17,6 +17,7 @@
     ManyToManyRel,
 )
 from django.db.models.base import ModelBase
+from graphql.execution.base import get_field_def
 from graphene.utils.str_converters import to_snake_case
 from graphene_django.utils import is_valid_django_model
 from graphql import GraphQLList, GraphQLNonNull
@@ -295,13 +296,23 @@ def find_field(field, fields_dict):
 
 
 def recursive_params(
-    selection_set, fragments, available_related_fields, select_related, prefetch_related
+        root_info,
+        current_parent_type,
+        selection_set,
+        fragments,
+        available_related_fields,
+        select_related,
+        prefetch_related,
 ):
 
     for field in selection_set.selections:
+        field_def = get_field_def(root_info.schema, current_parent_type, field.name.value)
+        field_type = get_type(field_def.type)
 
         if isinstance(field, FragmentSpread) and fragments:
             a, b = recursive_params(
+                root_info,
+                field_type,
                 fragments[field.name.value].selection_set,
                 fragments,
                 available_related_fields,
@@ -314,6 +325,8 @@ def recursive_params(
 
         if isinstance(field, InlineFragment):
             a, b = recursive_params(
+                root_info,
+                field_type,
                 field.selection_set,
                 fragments,
                 available_related_fields,
@@ -324,6 +337,11 @@ def recursive_params(
             [prefetch_related.append(x) for x in b if x not in prefetch_related]
             continue
 
+        optimization_hints = getattr(field_def.resolver, "optimization_hints", None)
+        if optimization_hints:
+            select_related = sorted(set(select_related) | optimization_hints.select_related)
+            prefetch_related = sorted(set(prefetch_related) | optimization_hints.prefetch_related)
+
         temp = available_related_fields.get(
             field.name.value,
             available_related_fields.get(to_snake_case(field.name.value), None),
@@ -336,6 +354,8 @@ def recursive_params(
                 select_related.append(temp.name)
         elif getattr(field, "selection_set", None):
             a, b = recursive_params(
+                root_info,
+                field_type,
                 field.selection_set,
                 fragments,
                 available_related_fields,
@@ -348,7 +368,9 @@ def recursive_params(
     return select_related, prefetch_related
 
 
-def queryset_factory(manager, fields_asts=None, fragments=None, **kwargs):
+def queryset_factory(manager, info, **kwargs):
+    fields_asts = info.field_asts
+    fragments = info.fragments
 
     select_related = []
     prefetch_related = []
@@ -364,8 +386,13 @@ def queryset_factory(manager, fields_asts=None, fragments=None, **kwargs):
             else:
                 select_related.append(temp.name)
 
+    base_field_def = get_field_def(info.schema, info.parent_type, info.field_name)
+    base_type = get_type(base_field_def.type)
+
     if fields_asts:
         select_related, prefetch_related = recursive_params(
+            info,
+            base_type,
             fields_asts[0].selection_set,
             fragments,
             available_related_fields,