Add example stress query (#583)

* Add stress query

* Update stress query to simplify structure

* Add instrumentation stress queries

* Update log statement

* Move instrumentation state to private class

Author: smyrick

examples/spring/src/main/kotlin/com/expediagroup/graphql/examples/directives/TrackTimesInvoked.kt

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+/*
+ * Copyright 2020 Expedia, Inc
+ *
+ * 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
+ *
+ *     https://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.
+ */
+
+package com.expediagroup.graphql.examples.directives
+
+import com.expediagroup.graphql.annotations.GraphQLDirective
+
+/**
+ * Used to verify the performance overhead of instrumentation on fields.
+ * Marker directive only, does not have DirectiveWiring.
+ */
+@GraphQLDirective(
+    name = TRACK_TIMES_INVOKED_DIRECTIVE_NAME,
+    description = "If the field is marked with this directive, " +
+        "we keep track of how many times this field was invoked per exection " +
+        "and log the result server side through graphql-java Instrumentation"
+)
+annotation class TrackTimesInvoked
+
+const val TRACK_TIMES_INVOKED_DIRECTIVE_NAME = "trackTimesInvoked"

examples/spring/src/main/kotlin/com/expediagroup/graphql/examples/instrumentation/TrackTimesInvokedInstrumentation.kt

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+/*
+ * Copyright 2020 Expedia, Inc
+ *
+ * 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
+ *
+ *     https://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.
+ */
+
+package com.expediagroup.graphql.examples.instrumentation
+
+import com.expediagroup.graphql.examples.directives.TRACK_TIMES_INVOKED_DIRECTIVE_NAME
+import graphql.ExecutionResult
+import graphql.execution.instrumentation.InstrumentationContext
+import graphql.execution.instrumentation.InstrumentationState
+import graphql.execution.instrumentation.SimpleInstrumentation
+import graphql.execution.instrumentation.SimpleInstrumentationContext
+import graphql.execution.instrumentation.parameters.InstrumentationExecutionParameters
+import graphql.execution.instrumentation.parameters.InstrumentationFieldFetchParameters
+import org.slf4j.LoggerFactory
+import org.springframework.stereotype.Component
+import java.util.concurrent.CompletableFuture
+import java.util.concurrent.ConcurrentHashMap
+
+/**
+ * Adds field count tracking in the instrumentation layer if [com.expediagroup.graphql.examples.directives.TrackTimesInvoked] is present.
+ */
+@Component
+class TrackTimesInvokedInstrumentation : SimpleInstrumentation() {
+
+    private val logger = LoggerFactory.getLogger(TrackTimesInvokedInstrumentation::class.java)
+
+    override fun createState(): InstrumentationState = TrackTimesInvokedInstrumenationState()
+
+    override fun beginFieldFetch(parameters: InstrumentationFieldFetchParameters): InstrumentationContext<Any> {
+        if (parameters.field.getDirective(TRACK_TIMES_INVOKED_DIRECTIVE_NAME) != null) {
+            (parameters.getInstrumentationState() as? TrackTimesInvokedInstrumenationState)?.incrementCount(parameters.field.name)
+        }
+
+        return SimpleInstrumentationContext<Any>()
+    }
+
+    override fun instrumentExecutionResult(executionResult: ExecutionResult, parameters: InstrumentationExecutionParameters): CompletableFuture<ExecutionResult> {
+        val count = (parameters.getInstrumentationState() as? TrackTimesInvokedInstrumenationState)?.getCount()
+        logger.info("TrackTimesInvokedInstrumentation fields invoked: $count")
+        return super.instrumentExecutionResult(executionResult, parameters)
+    }
+
+    /**
+     * The state per execution for this Instrumentation
+     */
+    private class TrackTimesInvokedInstrumenationState : InstrumentationState {
+
+        private val fieldCount = ConcurrentHashMap<String, Int>()
+
+        fun incrementCount(fieldName: String) {
+            val currentCount = fieldCount.getOrDefault(fieldName, 0)
+            fieldCount[fieldName] = currentCount.plus(1)
+        }
+
+        fun getCount() = fieldCount.toString()
+    }
+}

examples/spring/src/main/kotlin/com/expediagroup/graphql/examples/query/StressQuery.kt

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+/*
+ * Copyright 2020 Expedia, Inc
+ *
+ * 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
+ *
+ *     https://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.
+ */
+
+@file:Suppress("unused")
+
+package com.expediagroup.graphql.examples.query
+
+import com.expediagroup.graphql.examples.directives.TrackTimesInvoked
+import com.expediagroup.graphql.spring.operations.Query
+import io.netty.util.internal.ThreadLocalRandom
+import org.springframework.stereotype.Component
+import java.util.UUID
+
+/**
+ * Used to stress test the performance of running many data fetchers.
+ * Tests properties vs functions vs suspend functions.
+ */
+@Component
+class StressQuery : Query {
+
+    fun stressNode(traceId: String?, count: Int?): List<StressNode> {
+        val id = traceId ?: getRandomStringFromThread()
+        return (1..(count ?: 1)).map { StressNode(id) }
+    }
+}
+
+@Suppress("MemberVisibilityCanBePrivate", "RedundantSuspendModifier")
+class StressNode(val traceId: String) {
+
+    val valueId: String = getRandomStringFromThread()
+
+    fun functionId(): String = getRandomStringFromThread()
+
+    suspend fun suspendId(): String = getRandomStringFromThread()
+
+    @TrackTimesInvoked
+    fun loggingFunctionId(): String = getRandomStringFromThread()
+
+    @TrackTimesInvoked
+    suspend fun suspendLoggingFunctionId(): String = getRandomStringFromThread()
+}
+
+private fun getRandomStringFromThread(): String {
+    val random = ThreadLocalRandom.current()
+    return UUID(random.nextLong(), random.nextLong()).toString()
+}