Add execution stats to GraphQL responses

src/main/kotlin/info/jotajoti/jampuz/JampuzApplication.kt

@@ -2,6 +2,7 @@ package info.jotajoti.jampuz
 
 import graphql.scalars.*
 import info.jotajoti.jampuz.event.*
+import info.jotajoti.jampuz.graphql.*
 import info.jotajoti.jampuz.jidcode.*
 import info.jotajoti.jampuz.security.*
 import org.springframework.aot.hint.annotation.*
@@ -24,6 +25,7 @@ class GraphQlConfig {
     fun runtimeWiringConfigurer() =
         RuntimeWiringConfigurer { wiringBuilder ->
             wiringBuilder.scalar(ExtendedScalars.Date)
+            wiringBuilder.registerCostDirective()
         }
 }
 

src/main/kotlin/info/jotajoti/jampuz/graphql/CostDirective.kt

@@ -0,0 +1,35 @@
+package info.jotajoti.jampuz.graphql
+
+import graphql.schema.*
+import graphql.schema.idl.*
+import graphql.schema.idl.RuntimeWiring.*
+import org.springframework.graphql.server.*
+
+fun Builder.registerCostDirective(): Builder =
+    directive("Cost", CostDirective)
+
+val WebGraphQlResponse.calculatedCost: Int get() = executionInput.graphQLContext.getOrDefault(COST_KEY, 0)
+
+private object CostDirective : SchemaDirectiveWiring {
+    override fun onField(environment: SchemaDirectiveWiringEnvironment<GraphQLFieldDefinition>): GraphQLFieldDefinition =
+        environment.setFieldDataFetcher(
+            CostDataFetcher(
+                environment.appliedDirective,
+                environment.fieldDataFetcher
+            )
+        )
+}
+
+private class CostDataFetcher<T>(val appliedDirective: GraphQLAppliedDirective, dataFetcher: DataFetcher<T>) :
+    DataFetcherDelegate<T>(dataFetcher) {
+
+    override fun get(environment: DataFetchingEnvironment): T {
+        val cost = appliedDirective.getArgument("value").getValue<Int>()
+        environment.graphQlContext.compute<Int>(COST_KEY) { t, u ->
+            u?.let { u + cost } ?: cost
+        }
+        return super.get(environment)
+    }
+}
+
+private const val COST_KEY = "cost"

src/main/kotlin/info/jotajoti/jampuz/graphql/DataFetcherDelegate.kt

@@ -0,0 +1,11 @@
+package info.jotajoti.jampuz.graphql
+
+import graphql.schema.DataFetcher
+import graphql.schema.DataFetchingEnvironment
+
+abstract class DataFetcherDelegate<T>(val dataFetcher: DataFetcher<T>) : DataFetcher<T> {
+
+    override fun get(environment: DataFetchingEnvironment): T {
+        return dataFetcher.get(environment)
+    }
+}

src/main/kotlin/info/jotajoti/jampuz/graphql/GraphQLQueryStatsInterceptor.kt

@@ -0,0 +1,33 @@
+package info.jotajoti.jampuz.graphql
+
+import org.springframework.graphql.server.*
+import org.springframework.graphql.server.WebGraphQlInterceptor.*
+import org.springframework.stereotype.*
+import reactor.core.publisher.*
+
+@Component
+class GraphQLQueryStatsInterceptor : WebGraphQlInterceptor {
+
+    override fun intercept(request: WebGraphQlRequest, chain: Chain): Mono<WebGraphQlResponse> {
+        val start = System.currentTimeMillis()
+
+        return chain.next(request).map { response ->
+            val end = System.currentTimeMillis()
+            response.transform {
+                it.extensions(
+                    mapOf(
+                        "executionStats" to ExecutionStats(
+                            duration = end - start,
+                            cost = response.calculatedCost
+                        )
+                    )
+                )
+            }
+        }
+    }
+}
+
+data class ExecutionStats(
+    val duration: Long,
+    val cost: Int,
+)

src/main/resources/graphql/admin.graphqls

@@ -17,5 +17,5 @@ extend type Mutation {
 
 extend type Query {
     # Return null if not authenticated or if authentication is not an admin
-    authenticatedAdmin: Admin
+    authenticatedAdmin: Admin @Cost(value: 1)
 }

src/main/resources/graphql/event.graphqls

@@ -3,13 +3,13 @@ type Event {
     code: JidCode!
     year: Int!
     active: Boolean!
-    location: Location!
+    location: Location! @Cost(value: 5)
     # Returns true if event is latest for the location
-    isLatest: Boolean!
+    isLatest: Boolean! @Cost(value: 5)
     # Return previous year's event
-    previous: Event
+    previous: Event @Cost(value: 5)
     # Return next year's event
-    next: Event
+    next: Event @Cost(value: 5)
 }
 
 input CreateEventInput {
@@ -27,18 +27,18 @@ input UpdateEventInput {
 }
 
 extend type Location {
-    events: [Event!]!
-    latestEvent: Event
+    events: [Event!]! @Cost(value: 10)
+    latestEvent: Event @Cost(value: 5)
 }
 
 extend type Query {
     # If no year is provided the latest event is taken
     # Can be loaded without authentication
-    event(code: String!, year: Int): Event
+    event(code: String!, year: Int): Event @Cost(value: 5)
 
     # Load specific event by ID.
     # Requires admin authentication
-    eventById(eventId: ID!): Event
+    eventById(eventId: ID!): Event @Cost(value: 5)
 }
 
 extend type Mutation {

src/main/resources/graphql/jidcode.graphqls

@@ -9,21 +9,21 @@ enum Region {
 }
 
 type JidCode {
-    value: String!
-    region: Region!
+    value: String! @Cost(value: 1)
+    region: Region! @Cost(value: 1)
     # A lowercase [ISO3166-1 alpha-2](https://en.wikipedia.org/wiki/ISO_3166-1_alpha-2) country code
-    country: String!
+    country: String! @Cost(value: 1)
 }
 
 type JidCodeStats {
     id: ID!
     count: Int!
     uniqueCount: Int!
     uniqueCountryCount: Int!
-    countryStats: [CountryStat!]!
-    uniqueCountries: [String!]!
+    countryStats: [CountryStat!]! @Cost(value: 1)
+    uniqueCountries: [String!]! @Cost(value: 1)
     uniqueRegionCount: Int!
-    uniqueRegions: [Region!]!
+    uniqueRegions: [Region!]! @Cost(value: 1)
 }
 
 type CountryStat {
@@ -34,9 +34,9 @@ type CountryStat {
 }
 
 extend type Participant {
-    jidCodeStats: JidCodeStats!
+    jidCodeStats: JidCodeStats! @Cost(value: 10)
 }
 
 extend type Event {
-    jidCodeStats: JidCodeStats!
+    jidCodeStats: JidCodeStats! @Cost(value: 10)
 }

src/main/resources/graphql/location.graphqls

@@ -1,7 +1,7 @@
 type Location {
     id: ID!
     name: String!
-    owners: [Admin!]
+    owners: [Admin!] @Cost(value: 3)
 }
 
 input CreateLocationInput {
@@ -10,9 +10,9 @@ input CreateLocationInput {
 
 extend type Query {
     # Only returns locations owned by authenticated admin
-    locations: [Location!]
+    locations: [Location!] @Cost(value: 10)
     # Only returns location if owned by authenticated admin
-    location(locationId: ID!): Location
+    location(locationId: ID!): Location @Cost(value: 5)
 }
 
 extend type Mutation {

src/main/resources/graphql/participant.graphqls

@@ -1,18 +1,18 @@
 type Participant {
-    id: ID!
-    name: String!
+    id: ID! @Cost(value: 1)
+    name: String! @Cost(value: 1)
     # Pin code is only set if authenticated user is participant itself or an owner on the location
-    pinCode: String
+    pinCode: String @Cost(value: 1)
     # If not null, means this participant is linked to the Admin user so the admin also can act as participant.
-    admin: Admin
-    event: Event!
-    foundJidCodes: [FoundJidCode!]
+    admin: Admin @Cost(value: 5)
+    event: Event! @Cost(value: 5)
+    foundJidCodes: [FoundJidCode!] @Cost(value: 5)
 }
 
 type FoundJidCode {
-    id: ID!
-    code: JidCode!
-    participant: Participant!
+    id: ID! @Cost(value: 1)
+    code: JidCode! @Cost(value: 1)
+    participant: Participant! @Cost(value: 5)
 }
 
 input CreateParticipantInput {
@@ -26,7 +26,7 @@ input RegisterFoundJidCode {
 }
 
 extend type Event {
-    participants: [Participant!]!
+    participants: [Participant!]! @Cost(value: 5)
 }
 
 extend type Mutation {
@@ -40,5 +40,5 @@ extend type Query {
     # Return null if not authenticated or if authentication is not a participant
     # If eventJidCode is provided it will only return participant if the authenticated
     # participant is associated with the event
-    authenticatedParticipant(eventJidCode: String, year: Int): Participant
+    authenticatedParticipant(eventJidCode: String, year: Int): Participant @Cost(value: 1)
 }

src/main/resources/graphql/schema.graphqls

@@ -1,4 +1,5 @@
 scalar Date @specifiedBy(url: "https://tools.ietf.org/html/rfc3339")
+directive @Cost(value: Int!) on FIELD_DEFINITION
 
 type Mutation {
 }