added two new context settings that do not add dispatching instrumentation

Author: jmccaull

README.md

@@ -233,9 +233,9 @@ Here's an example of a GraphQL provider that implements three interfaces at the
 
 * [ExampleGraphQLProvider](examples/osgi/providers/src/main/java/graphql/servlet/examples/osgi/ExampleGraphQLProvider.java)
 
-## Request-scoped DataLoaders
+## Context and DataLoader settings
 
-It is possible to use dataloaders in both a request scope and a per query scope by customizing [GraphQLContextBuilder](https://github.com/graphql-java-kickstart/graphql-java-servlet/blob/master/src/main/java/graphql/servlet/context/GraphQLContextBuilder.java) and selecting the appropriate [ContextSetting](https://github.com/graphql-java-kickstart/graphql-java-servlet/blob/master/src/main/java/graphql/servlet/context/ContextSetting.java) with the provided [GraphQLConfiguration](https://github.com/graphql-java-kickstart/graphql-java-servlet/blob/master/src/main/java/graphql/servlet/config/GraphQLConfiguration.java).
+It is possible to create context, and consequently dataloaders, in both a request scope and a per query scope by customizing [GraphQLContextBuilder](https://github.com/graphql-java-kickstart/graphql-java-servlet/blob/master/src/main/java/graphql/servlet/context/GraphQLContextBuilder.java) and selecting the appropriate [ContextSetting](https://github.com/graphql-java-kickstart/graphql-java-servlet/blob/master/src/main/java/graphql/servlet/context/ContextSetting.java) with the provided [GraphQLConfiguration](https://github.com/graphql-java-kickstart/graphql-java-servlet/blob/master/src/main/java/graphql/servlet/config/GraphQLConfiguration.java).
 A new [DataLoaderRegistry](https://github.com/graphql-java/java-dataloader/blob/master/src/main/java/org/dataloader/DataLoaderRegistry.java) should be created in each call to the GraphQLContextBuilder, and the servlet will call the builder at the appropriate times.
 For eg:
 ```java
@@ -281,4 +281,6 @@ public class CustomGraphQLContextBuilder implements GraphQLContextBuilder {
      }
 
  ```
- If per request is selected, this will cause all queries within the http request, if using a batch, to share dataloader caches and batch together load calls as efficently as possible. The dataloaders are dispatched using instrumentation and the correct instrumentation will be selected according to the ContextSetting. The default context setting in GraphQLConfiguration is per query.
+ If per request is selected this will cause all queries within the http request, if using a batch, to share dataloader caches and batch together load calls as efficently as possible. The dataloaders are dispatched using instrumentation and the correct instrumentation will be selected according to the ContextSetting. The default context setting in GraphQLConfiguration is per query.
+ 
+ Two additional context settings are provided, one for each of the previous settings but without the addition of the Dataloader dispatching instrumentation. This is useful for those not using Dataloaders or wanting to supply their own dispatching instrumentation though the instrumentation supplier within the GraphQLQueryInvoker.

src/main/java/graphql/servlet/config/GraphQLConfiguration.java

@@ -111,7 +111,7 @@ public static class Builder {
         private boolean asyncServletModeEnabled = false;
         private Executor asyncExecutor = Executors.newCachedThreadPool(new GraphQLThreadFactory());
         private long subscriptionTimeout = 0;
-        private ContextSetting contextSetting = ContextSetting.PER_QUERY;
+        private ContextSetting contextSetting = ContextSetting.PER_QUERY_WITH_INSTRUMENTATION;
         private Supplier<BatchInputPreProcessor> batchInputPreProcessorSupplier = () -> new NoOpBatchInputPreProcessor();
 
         private Builder(GraphQLInvocationInputFactory.Builder invocationInputFactoryBuilder) {

src/main/java/graphql/servlet/context/ContextSetting.java

@@ -29,11 +29,13 @@ public enum ContextSetting {
     /**
      * A context object, and therefor dataloader registry and subject, should be shared between all GraphQL executions in a http request.
      */
-    PER_REQUEST,
+    PER_REQUEST_WITH_INSTRUMENTATION,
+    PER_REQUEST_WITHOUT_INSTRUMENTATION,
     /**
      * Each GraphQL execution should always have its own context.
      */
-    PER_QUERY;
+    PER_QUERY_WITH_INSTRUMENTATION,
+    PER_QUERY_WITHOUT_INSTRUMENTATION;
 
     /**
      * Creates a set of inputs with the correct context based on the setting.
@@ -45,9 +47,13 @@ public enum ContextSetting {
      */
     public GraphQLBatchedInvocationInput getBatch(List<GraphQLRequest> requests, GraphQLSchema schema, Supplier<GraphQLContext> contextSupplier, Object root) {
         switch (this) {
-            case PER_QUERY:
+            case PER_QUERY_WITH_INSTRUMENTATION:
+                //Intentional fallthrough
+            case PER_QUERY_WITHOUT_INSTRUMENTATION:
                 return new PerQueryBatchedInvocationInput(requests, schema, contextSupplier, root);
-            case PER_REQUEST:
+            case PER_REQUEST_WITHOUT_INSTRUMENTATION:
+                //Intentional fallthrough
+            case PER_REQUEST_WITH_INSTRUMENTATION:
                 return new PerRequestBatchedInvocationInput(requests, schema, contextSupplier.get(), root);
                 default:
                     throw new RuntimeException("Unconfigured context setting type");
@@ -65,18 +71,22 @@ public Supplier<Instrumentation> configureInstrumentationForContext(Supplier<Ins
                                                                         DataLoaderDispatcherInstrumentationOptions options) {
         ConfigurableDispatchInstrumentation dispatchInstrumentation;
         switch (this) {
-            case PER_REQUEST:
+            case PER_REQUEST_WITH_INSTRUMENTATION:
                 DataLoaderRegistry registry = executionInputs.stream().findFirst().map(ExecutionInput::getDataLoaderRegistry)
                     .orElseThrow(IllegalArgumentException::new);
                 List<ExecutionId> executionIds = executionInputs.stream().map(ExecutionInput::getExecutionId).collect(Collectors.toList());
                 RequestLevelTrackingApproach requestTrackingApproach = new RequestLevelTrackingApproach(executionIds, registry);
                 dispatchInstrumentation = new ConfigurableDispatchInstrumentation(options,
                     (dataLoaderRegistry -> requestTrackingApproach));
                 break;
-            case PER_QUERY:
+            case PER_QUERY_WITH_INSTRUMENTATION:
                 dispatchInstrumentation = new ConfigurableDispatchInstrumentation(options,
                     (dataLoaderRegistry) -> new FieldLevelTrackingApproach(dataLoaderRegistry));
                 break;
+            case PER_REQUEST_WITHOUT_INSTRUMENTATION:
+                //Intentional fallthrough
+            case PER_QUERY_WITHOUT_INSTRUMENTATION:
+                return () -> instrumentation.get();
                 default:
                     throw new RuntimeException("Unconfigured context setting type");
         }

src/test/groovy/graphql/servlet/DataLoaderDispatchingSpec.groovy

@@ -1,7 +1,6 @@
 package graphql.servlet
 
 import com.fasterxml.jackson.databind.ObjectMapper
-import graphql.execution.reactive.SingleSubscriberPublisher
 import graphql.schema.DataFetcher
 import graphql.schema.DataFetchingEnvironment
 import graphql.servlet.context.DefaultGraphQLContext
@@ -24,7 +23,6 @@ import javax.websocket.server.HandshakeRequest
 import java.util.concurrent.CompletableFuture
 import java.util.concurrent.CompletionStage
 import java.util.concurrent.atomic.AtomicInteger
-import java.util.concurrent.atomic.AtomicReference
 
 class DataLoaderDispatchingSpec extends Specification {
 
@@ -115,7 +113,7 @@ class DataLoaderDispatchingSpec extends Specification {
 
     def "batched query with per query context does not batch loads together"() {
         setup:
-        configureServlet(ContextSetting.PER_QUERY)
+        configureServlet(ContextSetting.PER_QUERY_WITH_INSTRUMENTATION)
         request.addParameter('query', '[{ "query": "query { query(arg:\\"test\\") { echo(arg:\\"test\\") { echo(arg:\\"test\\") } }}" }, { "query": "query{query(arg:\\"test\\") { echo (arg:\\"test\\") { echo(arg:\\"test\\")} }}" },' +
                 ' { "query": "query{queryTwo(arg:\\"test\\") { echo (arg:\\"test\\")}}" }, { "query": "query{queryTwo(arg:\\"test\\") { echo (arg:\\"test\\")}}" }]')
         resetCounters()
@@ -140,7 +138,7 @@ class DataLoaderDispatchingSpec extends Specification {
 
     def "batched query with per request context batches all queries within the request"() {
         setup:
-        servlet = configureServlet(ContextSetting.PER_REQUEST)
+        servlet = configureServlet(ContextSetting.PER_REQUEST_WITH_INSTRUMENTATION)
         request.addParameter('query', '[{ "query": "query { query(arg:\\"test\\") { echo(arg:\\"test\\") { echo(arg:\\"test\\") } }}" }, { "query": "query{query(arg:\\"test\\") { echo (arg:\\"test\\") { echo(arg:\\"test\\")} }}" },' +
                 ' { "query": "query{queryTwo(arg:\\"test\\") { echo (arg:\\"test\\")}}" }, { "query": "query{queryTwo(arg:\\"test\\") { echo (arg:\\"test\\")}}" }]')
         resetCounters()