Merge pull request #682 from Netflix/custom-generated-annotation

codegen: option to add @com.netflix.hollow.Generated annotation

hollow/src/main/java/com/netflix/hollow/HollowGenerated.java

@@ -0,0 +1,35 @@
+/*
+ *  Copyright 2016-2024 Netflix, 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
+ *
+ *         http://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.netflix.hollow;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+import static java.lang.annotation.ElementType.CONSTRUCTOR;
+import static java.lang.annotation.ElementType.METHOD;
+import static java.lang.annotation.ElementType.TYPE;
+
+/**
+ * This represents code that is generated by HollowAPIGenerator
+ * This is helpful for tools that instrument code, such as JaCoCo.
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target(value = {CONSTRUCTOR, METHOD, TYPE})
+@Documented
+public @interface HollowGenerated {}

hollow/src/main/java/com/netflix/hollow/api/codegen/AbstractHollowAPIGeneratorBuilder.java

@@ -154,6 +154,15 @@ public B withMetaInfo(Path metaInfoPath) {
         return getBuilder();
     }
 
+    /**
+     * Enable @Generated annotation in the generated API
+     * @return
+     */
+    public B withGeneratedAnnotation() {
+        config.setUseGeneratedAnnotation(true);
+        return getBuilder();
+    }
+
     public G build() {
         if (apiClassname == null)
             throw new IllegalStateException("Please specify an API classname (.withAPIClassname()) before calling .build()");

hollow/src/main/java/com/netflix/hollow/api/codegen/CodeGeneratorConfig.java

@@ -29,6 +29,7 @@ public class CodeGeneratorConfig {
     private boolean useHollowPrimitiveTypes = false;
     private boolean restrictApiToFieldType = false;
     private boolean useVerboseToString = false;
+    private boolean useGeneratedAnnotation = false;
 
     private boolean useMetaInfo = false;
     private Path metaInfoPath;
@@ -139,6 +140,15 @@ public void setUseVerboseToString(boolean useVerboseToString) {
         this.useVerboseToString = useVerboseToString;
     }
 
+    public boolean isUseGeneratedAnnotation() {
+        return useGeneratedAnnotation;
+    }
+
+    public void setUseGeneratedAnnotation(boolean useGeneratedAnnotation) {
+        this.useGeneratedAnnotation = useGeneratedAnnotation;
+    }
+
+
     @Override
     public int hashCode() {
         final int prime = 31;
@@ -149,6 +159,7 @@ public int hashCode() {
         result = prime * result + (restrictApiToFieldType ? 1231 : 1237);
         result = prime * result + (useAggressiveSubstitutions ? 1231 : 1237);
         result = prime * result + (useBooleanFieldErgonomics ? 1231 : 1237);
+        result = prime * result + (useGeneratedAnnotation ? 1231 : 1237);
         result = prime * result + (useHollowPrimitiveTypes ? 1231 : 1237);
         result = prime * result + (usePackageGrouping ? 1231 : 1237);
         result = prime * result + (useVerboseToString ? 1231 : 1237);
@@ -184,6 +195,8 @@ public boolean equals(Object obj) {
             return false;
         if (useBooleanFieldErgonomics != other.useBooleanFieldErgonomics)
             return false;
+        if (useGeneratedAnnotation != other.useGeneratedAnnotation)
+            return false;
         if (useHollowPrimitiveTypes != other.useHollowPrimitiveTypes)
             return false;
         if (usePackageGrouping != other.usePackageGrouping)
@@ -207,6 +220,8 @@ public String toString() {
         builder.append(classPostfix);
         builder.append(", getterPrefix=");
         builder.append(getterPrefix);
+        builder.append(", useGeneratedAnnotation=");
+        builder.append(useGeneratedAnnotation);
         builder.append(", usePackageGrouping=");
         builder.append(usePackageGrouping);
         builder.append(", useAggressiveSubstitutions=");

hollow/src/main/java/com/netflix/hollow/api/codegen/HollowAPIClassJavaGenerator.java

@@ -100,6 +100,8 @@ public String generate() {
         builder.append("import ").append(SampleResult.class.getName()).append(";\n");
         builder.append("import ").append(AllHollowRecordCollection.class.getName()).append(";\n");
 
+        appendGeneratedAnnotation(builder);
+
         builder.append("\n@SuppressWarnings(\"all\")\n");
         builder.append("public class ").append(className).append(" extends HollowAPI ");
         Set<String> primitiveTypes = HollowCodeGenerationUtils.getPrimitiveTypes(schemaList); // Implement Primitive Type Retriever(s)

hollow/src/main/java/com/netflix/hollow/api/codegen/HollowAPIFactoryJavaGenerator.java

@@ -54,6 +54,7 @@ public String generate() {
         builder.append("import ").append(Collections.class.getName()).append(";\n");
         builder.append("import ").append(Set.class.getName()).append(";\n");
 
+        appendGeneratedAnnotation(builder);
 
         builder.append("\n@SuppressWarnings(\"all\")\n");
         builder.append("public class ").append(className).append(" implements HollowAPIFactory {\n\n");

hollow/src/main/java/com/netflix/hollow/api/codegen/HollowConsumerJavaFileGenerator.java

@@ -15,6 +15,7 @@
  */
 package com.netflix.hollow.api.codegen;
 
+import com.netflix.hollow.HollowGenerated;
 import com.netflix.hollow.api.codegen.objects.HollowCollectionsGenerator;
 import com.netflix.hollow.core.HollowDataset;
 import com.netflix.hollow.core.schema.HollowListSchema;
@@ -129,6 +130,16 @@ protected void appendPackageAndCommonImports(StringBuilder builder,
         }
     }
 
+    /**
+     * Add @com.netflix.hollow.Generated annotation to the generated class
+     */
+    protected void appendGeneratedAnnotation(StringBuilder builder) {
+        if(config.isUseGeneratedAnnotation()) {
+            builder.append("import ").append(HollowGenerated.class.getName()).append(";\n");
+            builder.append("\n@HollowGenerated");
+        }
+    }
+
     private String createFullPackageName(String packageName, String subPackageName, boolean usePackageGrouping) {
         if (usePackageGrouping && !isEmpty(packageName) && !isEmpty(subPackageName)) {
             return packageName + "."  + subPackageName;

hollow/src/main/java/com/netflix/hollow/api/codegen/api/HollowDataAccessorGenerator.java

@@ -66,7 +66,8 @@ public String generate() {
         builder.append("import " + HollowReadStateEngine.class.getName() + ";\n");
 
         builder.append("\n");
-        builder.append("@SuppressWarnings(\"all\")\n");
+        appendGeneratedAnnotation(builder);
+        builder.append("\n@SuppressWarnings(\"all\")\n");
         builder.append("public class " + className + " extends " + AbstractHollowDataAccessor.class.getSimpleName() + "<" + type  +"> {\n\n");
 
         builder.append("    public static final String TYPE = \"" + schema.getName() + "\";\n");

hollow/src/main/java/com/netflix/hollow/api/codegen/api/TypeAPIListJavaGenerator.java

@@ -54,6 +54,7 @@ public String generate() {
         builder.append("import " + HollowListTypeDataAccess.class.getName() + ";\n");
         builder.append("import " + HollowListLookupDelegate.class.getName() + ";\n");
 
+        appendGeneratedAnnotation(builder);
         builder.append("\n@SuppressWarnings(\"all\")\n");
         builder.append("public class ").append(className).append(" extends HollowListTypeAPI {\n\n");
 

hollow/src/main/java/com/netflix/hollow/api/codegen/api/TypeAPIMapJavaGenerator.java

@@ -54,6 +54,8 @@ public String generate() {
         builder.append("import " + HollowMapTypeDataAccess.class.getName() + ";\n");
         builder.append("import " + HollowMapLookupDelegate.class.getName() + ";\n");
 
+        appendGeneratedAnnotation(builder);
+
         builder.append("\n@SuppressWarnings(\"all\")\n");
         builder.append("public class ").append(className).append(" extends HollowMapTypeAPI {\n\n");
 

hollow/src/main/java/com/netflix/hollow/api/codegen/api/TypeAPIObjectJavaGenerator.java

@@ -65,7 +65,8 @@ public TypeAPIObjectJavaGenerator(String apiClassname, String packageName, Hollo
     public String generate() {
         StringBuilder classBodyBuilder = new StringBuilder();
 
-        classBodyBuilder.append("@SuppressWarnings(\"all\")\n");
+        appendGeneratedAnnotation(classBodyBuilder);
+        classBodyBuilder.append("\n@SuppressWarnings(\"all\")\n");
         classBodyBuilder.append("public class " + className + " extends HollowObjectTypeAPI {\n\n");
 
         classBodyBuilder.append("    private final ").append(delegateLookupClassname(objectSchema)).append(" delegateLookupImpl;\n\n");

hollow/src/main/java/com/netflix/hollow/api/codegen/api/TypeAPISetJavaGenerator.java

@@ -54,6 +54,7 @@ public String generate() {
         builder.append("import " + HollowSetTypeDataAccess.class.getName() + ";\n");
         builder.append("import " + HollowSetLookupDelegate.class.getName() + ";\n");
 
+        appendGeneratedAnnotation(builder);
         builder.append("\n@SuppressWarnings(\"all\")\n");
         builder.append("public class ").append(className).append(" extends HollowSetTypeAPI {\n\n");
 

hollow/src/main/java/com/netflix/hollow/api/codegen/delegate/HollowObjectDelegateCachedImplGenerator.java

@@ -60,6 +60,7 @@ public String generate() {
         builder.append("import ").append(HollowTypeAPI.class.getName()).append(";\n");
         builder.append("import ").append(HollowCachedDelegate.class.getName()).append(";\n");
 
+        appendGeneratedAnnotation(builder);
         builder.append("\n@SuppressWarnings(\"all\")\n");
         builder.append("public class ").append(className).append(" extends HollowObjectAbstractDelegate implements HollowCachedDelegate, ").append(delegateInterfaceName(schema.getName())).append(" {\n\n");
 

hollow/src/main/java/com/netflix/hollow/api/codegen/delegate/HollowObjectDelegateLookupImplGenerator.java

@@ -54,6 +54,7 @@ public String generate() {
         builder.append("import ").append(HollowObjectTypeDataAccess.class.getName()).append(";\n");
         builder.append("import ").append(HollowObjectSchema.class.getName()).append(";\n");
 
+        appendGeneratedAnnotation(builder);
         builder.append("\n@SuppressWarnings(\"all\")\n");
         builder.append("public class ").append(className).append(" extends HollowObjectAbstractDelegate implements ").append(delegateInterfaceName(schema.getName())).append(" {\n\n");
 

hollow/src/main/java/com/netflix/hollow/api/codegen/indexes/HollowHashIndexGenerator.java

@@ -63,12 +63,14 @@ public String generate() {
         builder.append("import " + AbstractHollowHashIndex.class.getName() + ";\n");
         builder.append("import " + AbstractHollowOrdinalIterable.class.getName() + ";\n\n");
 
+        appendGeneratedAnnotation(builder);
+
         builder.append("\n");
         builder.append("/**\n");
         genDeprecatedJavaDoc(schemaList, builder);
         builder.append(" */\n");
         builder.append("@Deprecated\n");
-        builder.append("@SuppressWarnings(\"all\")\n");
+        builder.append("\n@SuppressWarnings(\"all\")\n");
         builder.append("public class " + className + " extends " + AbstractHollowHashIndex.class.getSimpleName() + "<" + apiClassname + "> {\n\n");
 
         builder.append("    public " + className + "(HollowConsumer consumer, String queryType, String selectFieldPath, String... matchFieldPaths) {\n");

hollow/src/main/java/com/netflix/hollow/api/codegen/indexes/HollowUniqueKeyIndexGenerator.java

@@ -65,11 +65,12 @@ public String generate() {
         if (isGenSimpleConstructor)
             builder.append("import " + HollowObjectSchema.class.getName() + ";\n");
 
+        appendGeneratedAnnotation(builder);
         builder.append("\n/**\n");
         genDeprecatedJavaDoc(builder);
         builder.append(" */\n");
         builder.append("@Deprecated\n");
-        builder.append("@SuppressWarnings(\"all\")\n");
+        builder.append("\n@SuppressWarnings(\"all\")\n");
         builder.append("public class " + className + " extends " + AbstractHollowUniqueKeyIndex.class.getSimpleName() + "<" + apiClassname + ", " + hollowImplClassname(type) + "> ");
         if (isImplementsUniqueKeyIndex) {
             builder.append("implements " + HollowUniqueKeyIndex.class.getSimpleName() + "<" + hollowImplClassname(type) + "> ");

hollow/src/main/java/com/netflix/hollow/api/codegen/objects/HollowFactoryJavaGenerator.java

@@ -72,6 +72,8 @@ public String generate() {
         if(schema instanceof HollowMapSchema)
             builder.append("import " + HollowMapCachedDelegate.class.getName() + ";\n");
 
+        appendGeneratedAnnotation(builder);
+
         builder.append("\n@SuppressWarnings(\"all\")\n");
         builder.append("public class " + className + "<T extends " + objectClassName + "> extends HollowFactory<T> {\n\n");
 

hollow/src/main/java/com/netflix/hollow/api/codegen/objects/HollowListJavaGenerator.java

@@ -61,7 +61,9 @@ public String generate() {
         builder.append("import " + HollowListDelegate.class.getName() + ";\n");
         builder.append("import " + GenericHollowRecordHelper.class.getName() + ";\n\n");
 
-        builder.append("@SuppressWarnings(\"all\")\n");
+         appendGeneratedAnnotation(builder);
+
+        builder.append("\n@SuppressWarnings(\"all\")\n");
         if(parameterize)
             builder.append("public class " + className + "<T> extends HollowList<T> {\n\n");
         else

hollow/src/main/java/com/netflix/hollow/api/codegen/objects/HollowMapJavaGenerator.java

@@ -68,7 +68,8 @@ public String generate() {
         builder.append("import " + HollowMapDelegate.class.getName() + ";\n");
         builder.append("import " + GenericHollowRecordHelper.class.getName() + ";\n\n");
 
-        builder.append("@SuppressWarnings(\"all\")\n");
+        appendGeneratedAnnotation(builder);
+        builder.append("\n@SuppressWarnings(\"all\")\n");
 
         String keyGeneric = parameterizeKey ? "K" : keyClassName;
         String valueGeneric = parameterizeValue ? "V" : valueClassName;

hollow/src/main/java/com/netflix/hollow/api/codegen/objects/HollowObjectJavaGenerator.java

@@ -109,7 +109,8 @@ public String generate() {
         }
         classBuilder.append("\n");
 
-        classBuilder.append("@SuppressWarnings(\"all\")\n");
+        appendGeneratedAnnotation(classBuilder);
+        classBuilder.append("\n@SuppressWarnings(\"all\")\n");
         if (requiresHollowTypeName) {
             classBuilder.append("@" + HollowTypeName.class.getSimpleName() + "(name=\"" + schema.getName() + "\")\n");
         }

hollow/src/main/java/com/netflix/hollow/api/codegen/objects/HollowSetJavaGenerator.java

@@ -62,7 +62,8 @@ public String generate() {
         builder.append("import " + HollowSetDelegate.class.getName() + ";\n");
         builder.append("import " + GenericHollowRecordHelper.class.getName() + ";\n\n");
 
-        builder.append("@SuppressWarnings(\"all\")\n");
+        appendGeneratedAnnotation(builder);
+        builder.append("\n@SuppressWarnings(\"all\")\n");
         if(parameterize)
             builder.append("public class " + className + "<T> extends HollowSet<T> {\n\n");
         else

hollow/src/main/java/com/netflix/hollow/api/codegen/perfapi/HollowObjectTypePerfAPIClassGenerator.java

@@ -43,7 +43,7 @@ public String generate() {
                 "import com.netflix.hollow.api.perfapi.Ref;\n" +
                 "import com.netflix.hollow.core.read.dataaccess.HollowDataAccess;\n\n");
 
-        builder.append("@SuppressWarnings(\"all\")\n");
+        builder.append("\n@SuppressWarnings(\"all\")\n");
         builder.append("public class " + schema.getName() + "PerfAPI extends HollowObjectTypePerfAPI {\n\n");
 
         builder.append("    public static final String fieldNames[] = { ");

hollow/src/main/java/com/netflix/hollow/api/codegen/perfapi/HollowPerformanceAPIClassGenerator.java

@@ -52,7 +52,7 @@ public String generate() {
                 "import java.util.Set;\n" +
                 "\n");
 
-        builder.append("@SuppressWarnings(\"all\")\n");
+        builder.append("\n@SuppressWarnings(\"all\")\n");
         builder.append("public class " + apiClassName + " extends HollowPerformanceAPI {\n\n");
 
         List<HollowSchema> schemas = new ArrayList<>(dataset.getSchemas());

hollow/src/test/java/com/netflix/hollow/api/codegen/AbstractHollowAPIGeneratorTest.java

@@ -20,14 +20,14 @@
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
 
+import com.netflix.hollow.HollowGenerated;
 import com.netflix.hollow.core.write.objectmapper.HollowTypeName;
 import java.io.File;
 import java.io.IOException;
 import java.lang.annotation.Annotation;
 import java.net.URL;
 import java.net.URLClassLoader;
 import java.nio.file.Path;
-import java.nio.file.Paths;
 import java.util.function.UnaryOperator;
 import org.junit.After;
 
@@ -37,7 +37,7 @@ public class AbstractHollowAPIGeneratorTest {
     protected String clazzFolder = String.format("%s/classes", tmpFolder);
     private Path metaInfoPath = null;
 
-    void runGenerator(String apiClassName, String packageName, Class<?> clazz,
+    protected void runGenerator(String apiClassName, String packageName, Class<?> clazz,
             UnaryOperator<HollowAPIGenerator.Builder> generatorCustomizer) throws Exception {
         System.out.println(String.format("Folders (%s) : \n\tsource=%s \n\tclasses=%s",
                     getClass().getSimpleName(), sourceFolder, clazzFolder));
@@ -71,6 +71,13 @@ void assertClassHasHollowTypeName(String clazz, String typeName) throws IOExcept
         assertEquals(typeName, ((HollowTypeName) annotation).name());
     }
 
+    protected void assertClassHasGeneratedAnnotation(String clazz) throws IOException, ClassNotFoundException {
+        ClassLoader cl = new URLClassLoader(new URL[]{new File(clazzFolder).toURI().toURL()});
+        Class cls = cl.loadClass(clazz);
+        Annotation annotation = cls.getAnnotation(HollowGenerated.class);
+        assertNotNull(annotation);
+    }
+
     void assertFileDoesNotExist(String relativePath) {
         if (relativePath.startsWith("/")) {
             throw new IllegalArgumentException("Relative paths should not start with /");

hollow/src/test/java/com/netflix/hollow/api/codegen/HollowAPIGeneratorTest.java

@@ -81,6 +81,14 @@ public void testGenerateWithPostfixAndAggressiveSubstitutions() throws Exception
         assertFileDoesNotExist("codegen/api/StringGenerated.java");
     }
 
+    @Test
+    public void testGenerateWithGeneratedAnnotation() throws Exception {
+        runGenerator("MyClassTestAPI", "codegen.api", MyClass.class,
+                builder -> builder.withClassPostfix("Generated").withGeneratedAnnotation());
+        assertClassHasGeneratedAnnotation("codegen.api.MyClassTestAPI");
+    }
+
+
     @SuppressWarnings("unused")
     @HollowPrimaryKey(fields = "id")
     private static class MyClass {

hollow/src/test/java/com/netflix/hollow/api/codegen/HollowBooleanFieldErgonomicsAPIGeneratorTest.java

@@ -24,7 +24,8 @@ public void test() throws Exception {
         String apiClassName = "BooleanErgoTestAPI";
         String packageName = "codegen.booleanfield.ergo";
         runGenerator(apiClassName, packageName, Movie.class,
-                builder -> builder.withBooleanFieldErgonomics(true));
+                builder -> builder.withBooleanFieldErgonomics(true).withGeneratedAnnotation());
+        assertClassHasGeneratedAnnotation(packageName + "." + apiClassName);
     }
 
     static class Movie {

hollow/src/test/java/com/netflix/hollow/api/codegen/HollowDataAccessorAPIGeneratorTest.java

@@ -34,6 +34,14 @@ public void testGenerateWithPostfix() throws Exception {
                 builder -> builder.withClassPostfix("Generated").withPackageGrouping());
     }
 
+    @Test
+    public void testGenerateWithGeneratedAnnotation() throws Exception {
+        runGenerator(API_CLASS_NAME, PACKAGE_NAME, Movie.class,
+                builder -> builder.withClassPostfix("Generated").withGeneratedAnnotation());
+        assertClassHasGeneratedAnnotation(PACKAGE_NAME + "." + API_CLASS_NAME);
+        assertClassHasGeneratedAnnotation(PACKAGE_NAME + ".StringGenerated");
+    }
+
     @HollowPrimaryKey(fields="id")
     static class Movie {
         int id;

hollow/src/test/java/com/netflix/hollow/api/codegen/HollowMapAPIGeneratorTest.java

@@ -57,4 +57,11 @@ public void test_withPackageGrouping() throws Exception {
     public void test_withoutPackageGrouping() throws Exception {
         runGenerator(API_CLASS_NAME, PACKAGE_NAME, Gru.class, b -> b);
     }
+
+    @Test
+    public void test_withGeneratedAnnotation() throws Exception {
+        runGenerator(API_CLASS_NAME, PACKAGE_NAME, Gru.class,
+                HollowAPIGenerator.Builder::withGeneratedAnnotation);
+        assertClassHasGeneratedAnnotation(PACKAGE_NAME + "." + API_CLASS_NAME);
+    }
 }