Improve CachingModelProvider to wrap a cache around the models it provides

headless-services/bosh-language-server/src/main/java/org/springframework/ide/vscode/bosh/BoshDeploymentManifestSchema.java

@@ -108,9 +108,9 @@ public class BoshDeploymentManifestSchema implements YamlSchema {
 	) {
 		this.asts = asts;
 		this.astTypes = astTypes;
-		this.cloudConfigProvider = new CachingModelProvider<>(cloudConfigProvider);
-		this.stemcellsProvider = new CachingModelProvider<>(stemcellsProvider);
-		this.releasesProvider = new CachingModelProvider<>(releasesProvider);
+		this.cloudConfigProvider = new CachingModelProvider<>(cloudConfigProvider, CloudConfigModel.class);
+		this.stemcellsProvider = new CachingModelProvider<>(stemcellsProvider, StemcellsModel.class);
+		this.releasesProvider = new CachingModelProvider<>(releasesProvider, ReleasesModel.class);
 		TYPE_UTIL = f.TYPE_UTIL;
 
 		V2_TOPLEVEL_TYPE = createV2Schema();

headless-services/bosh-language-server/src/main/java/org/springframework/ide/vscode/bosh/models/CachingModelProvider.java

@@ -10,6 +10,7 @@
  *******************************************************************************/
 package org.springframework.ide.vscode.bosh.models;
 
+import java.lang.reflect.Proxy;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.TimeUnit;
 import java.util.function.Function;
@@ -35,9 +36,11 @@ public class CachingModelProvider<T> implements DynamicModelProvider<T> {
 	private Cache<Object, CompletableFuture<T>> cache = createCache();
 
 	private final DynamicModelProvider<T> delegate;
+	private Class<T> modelInterface;
 
-	public CachingModelProvider(DynamicModelProvider<T> delegate) {
+	public CachingModelProvider(DynamicModelProvider<T> delegate, Class<T> modelInterface) {
 		this.delegate = delegate;
+		this.modelInterface = modelInterface;
 	}
 
 	/**
@@ -72,15 +75,37 @@ public class CachingModelProvider<T> implements DynamicModelProvider<T> {
 		synchronized (this) {
 			cached = cache.get(key, () -> {
 				try {
-					return CompletableFuture.completedFuture(delegate.getModel(dc));
+					return CompletableFuture.completedFuture(wrapWithCachingProxy(delegate.getModel(dc)));
 				} catch (Throwable e) {
-					CompletableFuture<T> failed = new CompletableFuture<>();
-					failed.completeExceptionally(e);
-					return failed;
+					return failed(e);
 				}
 			});
 		}
 		return cached.get();
 	}
 
+	private static <T> CompletableFuture<T> failed(Throwable e) {
+		CompletableFuture<T> failed = new CompletableFuture<>();
+		failed.completeExceptionally(e);
+		return failed;
+	}
+
+	@SuppressWarnings("unchecked")
+	private T wrapWithCachingProxy(T model) {
+		Cache<String, CompletableFuture<Object>> attributesCache = CacheBuilder.newBuilder().build();
+		return (T) Proxy.newProxyInstance(modelInterface.getClassLoader(), new Class[] {modelInterface}, (o, m, a) -> {
+			//We only support caching results for methods that have no arguments (for now, its all we need).
+			if (m.getParameterTypes().length==0) {
+				return attributesCache.get(m.getName(), () -> {
+					try {
+						return CompletableFuture.completedFuture((T)m.invoke(model, a));
+					} catch (Throwable e) {
+						return failed(e);
+					}
+				}).get();
+			}
+			return m.invoke(model, a);
+		});
+	}
+
 }

headless-services/bosh-language-server/src/test/java/org/springframework/ide/vscode/bosh/models/CachingModelProviderTest.java

@@ -12,9 +12,12 @@ package org.springframework.ide.vscode.bosh.models;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.fail;
-import static org.mockito.Mockito.*;
+import static org.mockito.Matchers.any;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
 
-import java.util.concurrent.ExecutionException;
 import java.util.concurrent.TimeoutException;
 
 import org.junit.Test;
@@ -23,24 +26,31 @@ import org.springframework.ide.vscode.commons.util.ExceptionUtil;
 @SuppressWarnings("unchecked")
 public class CachingModelProviderTest {
 
+	interface BoxModel {
+		String getContents();
+	}
+
 	@Test public void goodValuesAreCached() throws Exception {
-		DynamicModelProvider<String> modelProvider = mock(DynamicModelProvider.class);
-		when(modelProvider.getModel(any())).thenReturn("RESULT");
+		DynamicModelProvider<BoxModel> modelProvider = mock(DynamicModelProvider.class);
+		BoxModel model = mock(BoxModel.class);
+		when(modelProvider.getModel(any())).thenReturn(model);
+		when(model.getContents()).thenReturn("RESULT");
 
-		DynamicModelProvider<String> cached = new CachingModelProvider<>(modelProvider);
+		DynamicModelProvider<BoxModel> cached = new CachingModelProvider<>(modelProvider, BoxModel.class);
 
-		assertEquals("RESULT", cached.getModel(null));
-		assertEquals("RESULT", cached.getModel(null));
-		assertEquals("RESULT", cached.getModel(null));
+		assertEquals("RESULT", cached.getModel(null).getContents());
+		assertEquals("RESULT", cached.getModel(null).getContents());
+		assertEquals("RESULT", cached.getModel(null).getContents());
 
 		verify(modelProvider, times(1)).getModel(any());
+		verify(model, times(1)).getContents(); //model itself is also wrapped in a cache!
 	}
 
 	@Test public void timeoutExceptionsAreCached() throws Exception {
 		DynamicModelProvider<String> modelProvider = mock(DynamicModelProvider.class);
 		when(modelProvider.getModel(any())).thenThrow(new TimeoutException("timed out"));
 
-		DynamicModelProvider<String> cached = new CachingModelProvider<>(modelProvider);
+		DynamicModelProvider<String> cached = new CachingModelProvider<>(modelProvider, String.class);
 		for (int i = 0; i < 3; i++) {
 			try {
 				cached.getModel(null);

headless-services/commons/commons-language-server/src/main/java/org/springframework/ide/vscode/commons/languageserver/definition/SimpleDefinitionFinder.java

@@ -52,7 +52,7 @@ public class SimpleDefinitionFinder<T extends SimpleLanguageServer> implements D
 	 * currently pointed at in the current document using String.indexOf.
 	 */
 	protected Flux<Location> findDefinitions(TextDocumentPositionParams params) {
-			try {
+		try {
 			TextDocument doc = server.getTextDocumentService().get(params);
 			if (doc != null) {
 				int offset = doc.toOffset(params.getPosition());