@neo4j/graphql
Version:
A GraphQL to Cypher query execution layer for Neo4j and JavaScript GraphQL implementations
98 lines • 4.41 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.ComplexityEstimatorHelper = void 0;
/*
* Copyright (c) "Neo4j"
* Neo4j Sweden AB [http://neo4j.com]
*
* This file is part of Neo4j.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
const graphql_1 = require("graphql");
const graphql_query_complexity_1 = require("graphql-query-complexity");
class ComplexityEstimatorHelper {
constructor(useComplexityEstimators) {
this.useComplexityEstimators = useComplexityEstimators;
this.objectTypeNameToFieldNamesMapForComplexityExtensions = new Map();
}
registerField(parentObjectTypeNameOrInterfaceTypeName, fieldName) {
if (this.useComplexityEstimators) {
const existingFieldsForTypeName = this.objectTypeNameToFieldNamesMapForComplexityExtensions.get(parentObjectTypeNameOrInterfaceTypeName) ?? [];
this.objectTypeNameToFieldNamesMapForComplexityExtensions.set(parentObjectTypeNameOrInterfaceTypeName, existingFieldsForTypeName.concat(fieldName));
}
}
hydrateDefinitionNodeWithComplexityExtensions(definition) {
if (definition.kind !== graphql_1.Kind.OBJECT_TYPE_DEFINITION && definition.kind !== graphql_1.Kind.INTERFACE_TYPE_DEFINITION) {
return definition;
}
if (!this.objectTypeNameToFieldNamesMapForComplexityExtensions.has(definition.name.value)) {
return definition;
}
const fieldsWithComplexity = definition.fields?.map(f => {
const hasFieldComplexityEstimator = this.getFieldsForParentTypeName(definition.name.value).find(fieldName => fieldName === f.name.value);
if (!hasFieldComplexityEstimator) {
return f;
}
return {
...f,
extensions: {
// COMPLEXITY FORMULA
// c = c_child + lvl_limit * c_field, where
// c_field = 1
// lvl_limit defaults to 1
// c_child comes from simpleEstimator
complexity: ({ childComplexity, args }) => {
const fieldDefaultComplexity = 1;
const defaultLimitIfNotProvided = 1;
if (args.limit ?? args.first) {
return childComplexity + (args.limit ?? args.first) * fieldDefaultComplexity;
}
return childComplexity + defaultLimitIfNotProvided;
},
},
};
});
return {
...definition,
fields: fieldsWithComplexity,
};
}
hydrateSchemaFromSDLWithASTNodeExtensions(schema) {
const types = schema.getTypeMap();
Object.values(types).forEach((type) => {
if (type instanceof graphql_1.GraphQLObjectType || type instanceof graphql_1.GraphQLInterfaceType) {
const fields = type.getFields();
Object.values(fields).forEach((field) => {
if (field.astNode && 'extensions' in field.astNode) {
field.extensions = field.astNode.extensions;
}
});
}
});
}
getComplexityEstimators() {
if (!this.useComplexityEstimators) {
return [];
}
return [
(0, graphql_query_complexity_1.fieldExtensionsEstimator)(),
(0, graphql_query_complexity_1.simpleEstimator)({ defaultComplexity: 1 }),
];
}
getFieldsForParentTypeName(parentObjectTypeNameOrInterfaceTypeName) {
return this.objectTypeNameToFieldNamesMapForComplexityExtensions.get(parentObjectTypeNameOrInterfaceTypeName) || [];
}
}
exports.ComplexityEstimatorHelper = ComplexityEstimatorHelper;
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