use __slots__ in more places to lower memory footprint by a bit.

Author: jhgg

graphql/core/language/visitor.py

@@ -152,6 +152,8 @@ def visit(root, visitor, key_map=None):
 
 @six.add_metaclass(VisitorMeta)
 class Visitor(object):
+    __slots__ = ()
+
     def enter(self, node, key, parent, path, ancestors):
         method = self._get_enter_handler(type(node))
         if method:

graphql/core/utils/type_info.py

@@ -21,6 +21,9 @@ def pop(lst):
 # noinspection PyPep8Naming
 @six.add_metaclass(visitor_meta.VisitorMeta)
 class TypeInfo(object):
+    __slots__ = '_schema', '_type_stack', '_parent_type_stack', '_input_type_stack', '_field_def_stack', '_directive', \
+                '_argument'
+
     def __init__(self, schema):
         self._schema = schema
         self._type_stack = []

graphql/core/validation/__init__.py

@@ -6,12 +6,10 @@
 from .visitor import ValidationVisitor
 
 
-def validate(schema, ast, rules=None):
+def validate(schema, ast, rules=specified_rules):
     assert schema, 'Must provide schema'
     assert ast, 'Must provide document'
     assert isinstance(schema, GraphQLSchema)
-    if rules is None:
-        rules = specified_rules
     return visit_using_rules(schema, ast, rules)
 
 

graphql/core/validation/context.py

@@ -2,6 +2,8 @@
 
 
 class ValidationContext(object):
+    __slots__ = '_schema', '_ast', '_type_info', '_fragments'
+
     def __init__(self, schema, ast, type_info):
         self._schema = schema
         self._ast = ast

graphql/core/validation/rules/base.py

@@ -2,5 +2,7 @@
 
 
 class ValidationRule(Visitor):
+    __slots__ = 'context',
+
     def __init__(self, context):
         self.context = context

graphql/core/validation/rules/lone_anonymous_operation.py

@@ -4,9 +4,10 @@
 
 
 class LoneAnonymousOperation(ValidationRule):
-    operation_count = 0
+    __slots__ = 'operation_count',
 
     def __init__(self, context):
+        self.operation_count = 0
         super(LoneAnonymousOperation, self).__init__(context)
 
     def enter_Document(self, node, key, parent, path, ancestors):

graphql/core/validation/rules/no_fragment_cycles.py

@@ -5,6 +5,8 @@
 
 
 class NoFragmentCycles(ValidationRule):
+    __slots__ = 'spreads_in_fragment', 'known_to_lead_to_cycle'
+
     def __init__(self, context):
         super(NoFragmentCycles, self).__init__(context)
         self.spreads_in_fragment = {
@@ -59,6 +61,8 @@ def gather_spreads(cls, node):
         return visitor.collect_fragment_spread_nodes()
 
     class CollectFragmentSpreadNodesVisitor(Visitor):
+        __slots__ = 'spread_nodes',
+
         def __init__(self):
             self.spread_nodes = []
 

graphql/core/validation/rules/no_undefined_variables.py

@@ -4,12 +4,14 @@
 
 
 class NoUndefinedVariables(ValidationRule):
+    __slots__ = 'visited_fragment_names', 'defined_variable_names', 'operation',
     visit_spread_fragments = True
-    operation = None
 
     def __init__(self, context):
         self.visited_fragment_names = set()
         self.defined_variable_names = set()
+        self.operation = None
+
         super(NoUndefinedVariables, self).__init__(context)
 
     @staticmethod

graphql/core/validation/rules/no_unused_fragments.py

@@ -3,6 +3,8 @@
 
 
 class NoUnusedFragments(ValidationRule):
+    __slots__ = 'fragment_definitions', 'spreads_within_operation', 'fragment_adjacencies', 'spread_names'
+
     def __init__(self, context):
         super(NoUnusedFragments, self).__init__(context)
         self.fragment_definitions = []

graphql/core/validation/rules/no_unused_variables.py

@@ -3,12 +3,13 @@
 
 
 class NoUnusedVariables(ValidationRule):
-    visited_fragment_names = None
-    variable_definitions = None
-    variable_name_used = None
-    visit_spread_fragments = True
+    __slots__ = 'visited_fragment_names', 'variable_definitions', 'variable_name_used', 'visit_spread_fragments'
 
     def __init__(self, context):
+        self.visited_fragment_names = None
+        self.variable_definitions = None
+        self.variable_name_used = None
+        self.visit_spread_fragments = True
         super(NoUnusedVariables, self).__init__(context)
 
     def enter_OperationDefinition(self, node, key, parent, path, ancestors):
@@ -24,7 +25,7 @@ def leave_OperationDefinition(self, node, key, parent, path, ancestors):
             )
             for variable_definition in self.variable_definitions
             if variable_definition.variable.name.value not in self.variable_name_used
-        ]
+            ]
 
         if errors:
             return errors