From 5ee7884d91c4513e1b7322a4ca30a2c908e931b8 Mon Sep 17 00:00:00 2001 From: Jan Provaznik Date: Mon, 6 May 2019 21:24:19 +0000 Subject: [PATCH] GraphQL - Add extra complexity for resolvers If a field is a resolver, its complexity is automatically increased. By default we add extra points for sort and search arguments (which will be common for various resolvers). For specific resolvers we add field-specific complexity, e.g. for Issues complexity is increased if we filter issues by `labelName` (because then SQL query is more complex). We may want to tune these values in future depending on real-life results. Complexity is also dependent on the number of loaded nodes, but only if we don't search by specific ID(s). Also added complexity is limited (by default only twice more than child complexity) - the reason is that although it's more complex to process more items, the complexity increase is not linear (there is not so much difference between loading 10, 20 or 100 records from DB). --- app/graphql/resolvers/base_resolver.rb | 19 +++++++++++ .../resolvers/concerns/resolves_pipelines.rb | 10 ++++++ app/graphql/resolvers/issues_resolver.rb | 7 ++++ app/graphql/resolvers/project_resolver.rb | 4 +++ app/graphql/types/base_field.rb | 34 +++++++++++++++++-- app/graphql/types/issue_type.rb | 6 ++-- .../graphql-resolvers-complexity.yml | 6 ++++ spec/graphql/resolvers/base_resolver_spec.rb | 15 ++++++++ .../concerns/resolves_pipelines_spec.rb | 8 +++++ .../graphql/resolvers/issues_resolver_spec.rb | 7 ++++ .../resolvers/project_resolver_spec.rb | 8 +++++ spec/graphql/types/base_field_spec.rb | 26 ++++++++++++++ 12 files changed, 146 insertions(+), 4 deletions(-) create mode 100644 changelogs/unreleased/graphql-resolvers-complexity.yml diff --git a/app/graphql/resolvers/base_resolver.rb b/app/graphql/resolvers/base_resolver.rb index 063def75d38..31850c2cadb 100644 --- a/app/graphql/resolvers/base_resolver.rb +++ b/app/graphql/resolvers/base_resolver.rb @@ -9,5 +9,24 @@ module Resolvers end end end + + def self.resolver_complexity(args) + complexity = 1 + complexity += 1 if args[:sort] + complexity += 5 if args[:search] + + complexity + end + + def self.complexity_multiplier(args) + # When fetching many items, additional complexity is added to the field + # depending on how many items is fetched. For each item we add 1% of the + # original complexity - this means that loading 100 items (our default + # maxp_age_size limit) doubles the original complexity. + # + # Complexity is not increased when searching by specific ID(s), because + # complexity difference is minimal in this case. + [args[:iid], args[:iids]].any? ? 0 : 0.01 + end end end diff --git a/app/graphql/resolvers/concerns/resolves_pipelines.rb b/app/graphql/resolvers/concerns/resolves_pipelines.rb index 8fd26d85994..a166211fc18 100644 --- a/app/graphql/resolvers/concerns/resolves_pipelines.rb +++ b/app/graphql/resolvers/concerns/resolves_pipelines.rb @@ -19,6 +19,16 @@ module ResolvesPipelines description: "Filter pipelines by the sha of the commit they are run for" end + class_methods do + def resolver_complexity(args) + complexity = super + complexity += 2 if args[:sha] + complexity += 2 if args[:ref] + + complexity + end + end + def resolve_pipelines(project, params = {}) PipelinesFinder.new(project, context[:current_user], params).execute end diff --git a/app/graphql/resolvers/issues_resolver.rb b/app/graphql/resolvers/issues_resolver.rb index 54d32a688bf..1c3c24ad6dc 100644 --- a/app/graphql/resolvers/issues_resolver.rb +++ b/app/graphql/resolvers/issues_resolver.rb @@ -57,5 +57,12 @@ module Resolvers IssuesFinder.new(context[:current_user], args).execute end + + def self.resolver_complexity(args) + complexity = super + complexity += 2 if args[:labelName] + + complexity + end end end diff --git a/app/graphql/resolvers/project_resolver.rb b/app/graphql/resolvers/project_resolver.rb index ac7c9b0ce2e..2132447da5e 100644 --- a/app/graphql/resolvers/project_resolver.rb +++ b/app/graphql/resolvers/project_resolver.rb @@ -9,5 +9,9 @@ module Resolvers def resolve(full_path:) model_by_full_path(Project, full_path) end + + def self.complexity_multiplier(args) + 0 + end end end diff --git a/app/graphql/types/base_field.rb b/app/graphql/types/base_field.rb index 8c8b8a82d3e..15331129134 100644 --- a/app/graphql/types/base_field.rb +++ b/app/graphql/types/base_field.rb @@ -7,10 +7,40 @@ module Types DEFAULT_COMPLEXITY = 1 def initialize(*args, **kwargs, &block) - # complexity is already defaulted to 1, but let's make it explicit - kwargs[:complexity] ||= DEFAULT_COMPLEXITY + kwargs[:complexity] ||= field_complexity(kwargs[:resolver_class]) super(*args, **kwargs, &block) end + + private + + def field_complexity(resolver_class) + if resolver_class + field_resolver_complexity + else + DEFAULT_COMPLEXITY + end + end + + def field_resolver_complexity + # Complexity can be either integer or proc. If proc is used then it's + # called when computing a query complexity and context and query + # arguments are available for computing complexity. For resolvers we use + # proc because we set complexity depending on arguments and number of + # items which can be loaded. + proc do |ctx, args, child_complexity| + page_size = @max_page_size || ctx.schema.default_max_page_size + limit_value = [args[:first], args[:last], page_size].compact.min + + # Resolvers may add extra complexity depending on used arguments + complexity = child_complexity + self.resolver&.try(:resolver_complexity, args).to_i + + # Resolvers may add extra complexity depending on number of items being loaded. + multiplier = self.resolver&.try(:complexity_multiplier, args).to_f + complexity += complexity * limit_value * multiplier + + complexity.to_i + end + end end end diff --git a/app/graphql/types/issue_type.rb b/app/graphql/types/issue_type.rb index adb137dfee3..b21a226d07f 100644 --- a/app/graphql/types/issue_type.rb +++ b/app/graphql/types/issue_type.rb @@ -19,9 +19,11 @@ module Types null: false, resolve: -> (obj, _args, _ctx) { Gitlab::Graphql::Loaders::BatchModelLoader.new(User, obj.author_id).find } - field :assignees, Types::UserType.connection_type, null: true + # Remove complexity when BatchLoader is used + field :assignees, Types::UserType.connection_type, null: true, complexity: 5 - field :labels, Types::LabelType.connection_type, null: true + # Remove complexity when BatchLoader is used + field :labels, Types::LabelType.connection_type, null: true, complexity: 5 field :milestone, Types::MilestoneType, null: true, resolve: -> (obj, _args, _ctx) { Gitlab::Graphql::Loaders::BatchModelLoader.new(Milestone, obj.milestone_id).find } diff --git a/changelogs/unreleased/graphql-resolvers-complexity.yml b/changelogs/unreleased/graphql-resolvers-complexity.yml new file mode 100644 index 00000000000..503ffbd97f2 --- /dev/null +++ b/changelogs/unreleased/graphql-resolvers-complexity.yml @@ -0,0 +1,6 @@ +--- +title: 'GraphQL: improve evaluation of query complexity based on arguments and query + limits.' +merge_request: 28017 +author: +type: added diff --git a/spec/graphql/resolvers/base_resolver_spec.rb b/spec/graphql/resolvers/base_resolver_spec.rb index e3a34762b62..9982288e206 100644 --- a/spec/graphql/resolvers/base_resolver_spec.rb +++ b/spec/graphql/resolvers/base_resolver_spec.rb @@ -28,4 +28,19 @@ describe Resolvers::BaseResolver do expect(result).to eq(test: 1) end end + + it 'increases complexity based on arguments' do + field = Types::BaseField.new(name: 'test', type: GraphQL::STRING_TYPE, resolver_class: described_class, null: false, max_page_size: 1) + + expect(field.to_graphql.complexity.call({}, { sort: 'foo' }, 1)).to eq 3 + expect(field.to_graphql.complexity.call({}, { search: 'foo' }, 1)).to eq 7 + end + + it 'does not increase complexity when filtering by iids' do + field = Types::BaseField.new(name: 'test', type: GraphQL::STRING_TYPE, resolver_class: described_class, null: false, max_page_size: 100) + + expect(field.to_graphql.complexity.call({}, { sort: 'foo' }, 1)).to eq 6 + expect(field.to_graphql.complexity.call({}, { sort: 'foo', iid: 1 }, 1)).to eq 3 + expect(field.to_graphql.complexity.call({}, { sort: 'foo', iids: [1, 2, 3] }, 1)).to eq 3 + end end diff --git a/spec/graphql/resolvers/concerns/resolves_pipelines_spec.rb b/spec/graphql/resolvers/concerns/resolves_pipelines_spec.rb index ea7159eacf9..3140af27af5 100644 --- a/spec/graphql/resolvers/concerns/resolves_pipelines_spec.rb +++ b/spec/graphql/resolvers/concerns/resolves_pipelines_spec.rb @@ -46,6 +46,14 @@ describe ResolvesPipelines do expect(resolve_pipelines({}, {})).to be_empty end + it 'increases field complexity based on arguments' do + field = Types::BaseField.new(name: 'test', type: GraphQL::STRING_TYPE, resolver_class: resolver, null: false, max_page_size: 1) + + expect(field.to_graphql.complexity.call({}, {}, 1)).to eq 2 + expect(field.to_graphql.complexity.call({}, { sha: 'foo' }, 1)).to eq 4 + expect(field.to_graphql.complexity.call({}, { sha: 'ref' }, 1)).to eq 4 + end + def resolve_pipelines(args = {}, context = { current_user: current_user }) resolve(resolver, obj: project, args: args, ctx: context) end diff --git a/spec/graphql/resolvers/issues_resolver_spec.rb b/spec/graphql/resolvers/issues_resolver_spec.rb index 399a33dae75..bffcdbfe915 100644 --- a/spec/graphql/resolvers/issues_resolver_spec.rb +++ b/spec/graphql/resolvers/issues_resolver_spec.rb @@ -120,6 +120,13 @@ describe Resolvers::IssuesResolver do end end + it 'increases field complexity based on arguments' do + field = Types::BaseField.new(name: 'test', type: GraphQL::STRING_TYPE, resolver_class: described_class, null: false, max_page_size: 100) + + expect(field.to_graphql.complexity.call({}, {}, 1)).to eq 4 + expect(field.to_graphql.complexity.call({}, { labelName: 'foo' }, 1)).to eq 8 + end + def resolve_issues(args = {}, context = { current_user: current_user }) resolve(described_class, obj: project, args: args, ctx: context) end diff --git a/spec/graphql/resolvers/project_resolver_spec.rb b/spec/graphql/resolvers/project_resolver_spec.rb index d4990c6492c..4fdbb3aa43e 100644 --- a/spec/graphql/resolvers/project_resolver_spec.rb +++ b/spec/graphql/resolvers/project_resolver_spec.rb @@ -26,6 +26,14 @@ describe Resolvers::ProjectResolver do end end + it 'does not increase complexity depending on number of load limits' do + field1 = Types::BaseField.new(name: 'test', type: GraphQL::STRING_TYPE, resolver_class: described_class, null: false, max_page_size: 100) + field2 = Types::BaseField.new(name: 'test', type: GraphQL::STRING_TYPE, resolver_class: described_class, null: false, max_page_size: 1) + + expect(field1.to_graphql.complexity.call({}, {}, 1)).to eq 2 + expect(field2.to_graphql.complexity.call({}, {}, 1)).to eq 2 + end + def resolve_project(full_path) resolve(described_class, args: { full_path: full_path }) end diff --git a/spec/graphql/types/base_field_spec.rb b/spec/graphql/types/base_field_spec.rb index b5697ee5245..4fe426e2447 100644 --- a/spec/graphql/types/base_field_spec.rb +++ b/spec/graphql/types/base_field_spec.rb @@ -4,6 +4,18 @@ require 'spec_helper' describe Types::BaseField do context 'when considering complexity' do + let(:resolver) do + Class.new(described_class) do + def self.resolver_complexity(args) + 2 if args[:foo] + end + + def self.complexity_multiplier(args) + 0.01 + end + end + end + it 'defaults to 1' do field = described_class.new(name: 'test', type: GraphQL::STRING_TYPE, null: true) @@ -15,5 +27,19 @@ describe Types::BaseField do expect(field.to_graphql.complexity).to eq 12 end + + it 'sets complexity depending on arguments for resolvers' do + field = described_class.new(name: 'test', type: GraphQL::STRING_TYPE, resolver_class: resolver, max_page_size: 100, null: true) + + expect(field.to_graphql.complexity.call({}, {}, 2)).to eq 4 + expect(field.to_graphql.complexity.call({}, { first: 50 }, 2)).to eq 3 + end + + it 'sets complexity depending on number load limits for resolvers' do + field = described_class.new(name: 'test', type: GraphQL::STRING_TYPE, resolver_class: resolver, max_page_size: 100, null: true) + + expect(field.to_graphql.complexity.call({}, { first: 1 }, 2)).to eq 2 + expect(field.to_graphql.complexity.call({}, { first: 1, foo: true }, 2)).to eq 4 + end end end