feat(codegen): generate empty SdkWarmUpProvider and META-INF/services registration per service

codegen/src/main/java/software/amazon/awssdk/codegen/emitters/GeneratorPathProvider.java

@@ -107,4 +107,8 @@ public String getAuthSchemeInternalDirectory() {
     public String getJmesPathInternalDirectory() {
         return sourceDirectory + "/" + Utils.packageToDirectory(model.getMetadata().getFullInternalJmesPathPackageName());
     }
+
+    public String getWarmUpProviderDirectory() {
+        return sourceDirectory + "/" + Utils.packageToDirectory(model.getMetadata().getFullCracInternalPackageName());
+    }
 }

codegen/src/main/java/software/amazon/awssdk/codegen/emitters/WarmUpProviderRegistrationTask.java

@@ -0,0 +1,72 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file 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 software.amazon.awssdk.codegen.emitters;
+
+import java.io.IOException;
+import java.io.UncheckedIOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.nio.file.StandardOpenOption;
+import java.util.List;
+
+/**
+ * Appends a generated {@code SdkWarmUpProvider} implementation's fully-qualified class name to the shared
+ * {@code META-INF/services/software.amazon.awssdk.core.crac.SdkWarmUpProvider} resource file.
+ *
+ * <p>This task writes a plain resource file rather than a {@code .java} file, so it does not use
+ * {@link SimpleGeneratorTask}. It creates the file once and appends to it for each subsequent service, and
+ * re-registering the same class name is a no-op.
+ */
+public final class WarmUpProviderRegistrationTask extends GeneratorTask {
+
+    private static final String SPI_RESOURCE_PATH =
+        "META-INF/services/software.amazon.awssdk.core.crac.SdkWarmUpProvider";
+
+    private final String resourcesDirectory;
+    private final String providerClassName;
+
+    public WarmUpProviderRegistrationTask(String resourcesDirectory, String providerClassName) {
+        this.resourcesDirectory = resourcesDirectory;
+        this.providerClassName = providerClassName;
+    }
+
+    @Override
+    public void compute() {
+        try {
+            Path file = Paths.get(resourcesDirectory, SPI_RESOURCE_PATH);
+            Path parent = file.getParent();
+            if (parent != null) {
+                Files.createDirectories(parent);
+            }
+
+            if (Files.exists(file)) {
+                List<String> lines = Files.readAllLines(file, StandardCharsets.UTF_8);
+                if (lines.contains(providerClassName)) {
+                    return;
+                }
+            }
+
+            Files.write(file,
+                        (providerClassName + "\n").getBytes(StandardCharsets.UTF_8),
+                        StandardOpenOption.CREATE,
+                        StandardOpenOption.APPEND);
+        } catch (IOException e) {
+            throw new UncheckedIOException("Failed to register warm up provider " + providerClassName, e);
+        }
+    }
+}

codegen/src/main/java/software/amazon/awssdk/codegen/emitters/tasks/AwsGeneratorTasks.java

@@ -28,6 +28,7 @@ public AwsGeneratorTasks(GeneratorTaskParams params) {
               new EventStreamGeneratorTasks(params),
               new WaitersGeneratorTasks(params),
               new EndpointProviderTasks(params),
-              new AuthSchemeGeneratorTasks(params));
+              new AuthSchemeGeneratorTasks(params),
+              new WarmUpProviderTasks(params));
     }
 }

codegen/src/main/java/software/amazon/awssdk/codegen/emitters/tasks/WarmUpProviderTasks.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file 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 software.amazon.awssdk.codegen.emitters.tasks;
+
+import java.util.ArrayList;
+import java.util.List;
+import software.amazon.awssdk.codegen.emitters.GeneratorTask;
+import software.amazon.awssdk.codegen.emitters.GeneratorTaskParams;
+import software.amazon.awssdk.codegen.emitters.PoetGeneratorTask;
+import software.amazon.awssdk.codegen.emitters.WarmUpProviderRegistrationTask;
+import software.amazon.awssdk.codegen.poet.crac.WarmUpProviderSpec;
+
+/**
+ * Emits the per-service {@code SdkWarmUpProvider} implementation and its {@code META-INF/services} registration.
+ */
+public final class WarmUpProviderTasks extends BaseGeneratorTasks {
+
+    private final GeneratorTaskParams params;
+
+    public WarmUpProviderTasks(GeneratorTaskParams params) {
+        super(params);
+        this.params = params;
+    }
+
+    @Override
+    protected List<GeneratorTask> createTasks() throws Exception {
+        List<GeneratorTask> tasks = new ArrayList<>();
+
+        WarmUpProviderSpec spec = new WarmUpProviderSpec(model);
+
+        tasks.add(new PoetGeneratorTask(warmUpProviderDir(), model.getFileHeader(), spec));
+        tasks.add(new WarmUpProviderRegistrationTask(params.getPathProvider().getResourcesDirectory(),
+                                                     spec.className().toString()));
+        return tasks;
+    }
+
+    private String warmUpProviderDir() {
+        return params.getPathProvider().getWarmUpProviderDirectory();
+    }
+}

codegen/src/main/java/software/amazon/awssdk/codegen/model/intermediate/Metadata.java

@@ -775,6 +775,10 @@ public String getFullInternalPackageName() {
         return joinPackageNames(getFullClientPackageName(), "internal");
     }
 
+    public String getFullCracInternalPackageName() {
+        return joinPackageNames(getFullInternalPackageName(), "crac");
+    }
+
     public Metadata setJmesPathPackageName(String jmesPathPackageName) {
         this.jmesPathPackageName = jmesPathPackageName;
         return this;

codegen/src/main/java/software/amazon/awssdk/codegen/poet/crac/WarmUpProviderSpec.java

@@ -0,0 +1,63 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file 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 software.amazon.awssdk.codegen.poet.crac;
+
+import com.squareup.javapoet.ClassName;
+import com.squareup.javapoet.MethodSpec;
+import com.squareup.javapoet.TypeSpec;
+import javax.lang.model.element.Modifier;
+import software.amazon.awssdk.annotations.SdkInternalApi;
+import software.amazon.awssdk.codegen.model.intermediate.IntermediateModel;
+import software.amazon.awssdk.codegen.poet.ClassSpec;
+import software.amazon.awssdk.codegen.poet.PoetUtils;
+import software.amazon.awssdk.core.crac.SdkWarmUpProvider;
+
+/**
+ * Generates an empty {@link SdkWarmUpProvider} implementation per service. The {@code warmUp()} body is intentionally a
+ * no-op in this stage; the synthetic priming call is added in a later stage. ServiceLoader requires a public no-arg
+ * constructor, which the default constructor satisfies.
+ */
+public class WarmUpProviderSpec implements ClassSpec {
+
+    private final IntermediateModel model;
+
+    public WarmUpProviderSpec(IntermediateModel model) {
+        this.model = model;
+    }
+
+    @Override
+    public ClassName className() {
+        return ClassName.get(model.getMetadata().getFullCracInternalPackageName(),
+                             model.getMetadata().getServiceName() + "WarmUpProvider");
+    }
+
+    @Override
+    public TypeSpec poetSpec() {
+        return PoetUtils.createClassBuilder(className())
+                        .addModifiers(Modifier.PUBLIC, Modifier.FINAL)
+                        .addAnnotation(SdkInternalApi.class)
+                        .addSuperinterface(SdkWarmUpProvider.class)
+                        .addMethod(warmUpMethod())
+                        .build();
+    }
+
+    private MethodSpec warmUpMethod() {
+        return MethodSpec.methodBuilder("warmUp")
+                         .addAnnotation(Override.class)
+                         .addModifiers(Modifier.PUBLIC)
+                         .build();
+    }
+}

codegen/src/test/java/software/amazon/awssdk/codegen/emitters/GeneratorPathProviderTest.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file 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 software.amazon.awssdk.codegen.emitters;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.junit.jupiter.api.Test;
+import software.amazon.awssdk.codegen.model.intermediate.IntermediateModel;
+import software.amazon.awssdk.codegen.model.intermediate.Metadata;
+
+public class GeneratorPathProviderTest {
+
+    @Test
+    public void warmUpProviderDirectory_isUnderSourceDirInCracInternalPackage() {
+        Metadata metadata = new Metadata();
+        metadata.setRootPackageName("software.amazon.awssdk.services");
+        metadata.setClientPackageName("query");
+
+        IntermediateModel model = new IntermediateModel();
+        model.setMetadata(metadata);
+
+        GeneratorPathProvider provider =
+            new GeneratorPathProvider(model, "/src", "/test", "/resources");
+
+        assertThat(provider.getWarmUpProviderDirectory())
+            .isEqualTo("/src/software/amazon/awssdk/services/query/internal/crac");
+    }
+}

codegen/src/test/java/software/amazon/awssdk/codegen/emitters/WarmUpProviderRegistrationTaskTest.java

@@ -0,0 +1,68 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file 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 software.amazon.awssdk.codegen.emitters;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static software.amazon.awssdk.codegen.poet.ClientTestModels.queryServiceModels;
+import static software.amazon.awssdk.codegen.poet.ClientTestModels.xmlServiceModels;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.List;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+import software.amazon.awssdk.codegen.poet.crac.WarmUpProviderSpec;
+
+public class WarmUpProviderRegistrationTaskTest {
+
+    private static final String SPI_PATH =
+        "META-INF/services/software.amazon.awssdk.core.crac.SdkWarmUpProvider";
+
+    private static final String QUERY_PROVIDER = new WarmUpProviderSpec(queryServiceModels()).className().toString();
+    private static final String XML_PROVIDER = new WarmUpProviderSpec(xmlServiceModels()).className().toString();
+
+    @TempDir
+    Path resourcesDir;
+
+    @Test
+    public void writesProviderClassName() throws IOException {
+        new WarmUpProviderRegistrationTask(resourcesDir.toString(), QUERY_PROVIDER).compute();
+
+        List<String> lines = Files.readAllLines(resourcesDir.resolve(SPI_PATH), StandardCharsets.UTF_8);
+        assertThat(lines).contains(QUERY_PROVIDER);
+    }
+
+    @Test
+    public void appendsSecondProviderWithoutClobbering() throws IOException {
+        new WarmUpProviderRegistrationTask(resourcesDir.toString(), QUERY_PROVIDER).compute();
+        new WarmUpProviderRegistrationTask(resourcesDir.toString(), XML_PROVIDER).compute();
+
+        List<String> lines = Files.readAllLines(resourcesDir.resolve(SPI_PATH), StandardCharsets.UTF_8);
+        assertThat(lines).contains(QUERY_PROVIDER).contains(XML_PROVIDER);
+    }
+
+    @Test
+    public void doesNotDuplicateOnSecondIdenticalRun() throws IOException {
+        new WarmUpProviderRegistrationTask(resourcesDir.toString(), QUERY_PROVIDER).compute();
+        new WarmUpProviderRegistrationTask(resourcesDir.toString(), QUERY_PROVIDER).compute();
+
+        List<String> lines = Files.readAllLines(resourcesDir.resolve(SPI_PATH), StandardCharsets.UTF_8);
+        long count = lines.stream().filter(l -> l.equals(QUERY_PROVIDER)).count();
+        assertThat(count).isEqualTo(1);
+    }
+}

codegen/src/test/java/software/amazon/awssdk/codegen/model/intermediate/MetadataTest.java

@@ -0,0 +1,33 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file 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 software.amazon.awssdk.codegen.model.intermediate;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.junit.jupiter.api.Test;
+
+public class MetadataTest {
+
+    @Test
+    public void fullCracInternalPackageName_appendsInternalCracToClientPackage() {
+        Metadata metadata = new Metadata();
+        metadata.setRootPackageName("software.amazon.awssdk.services");
+        metadata.setClientPackageName("query");
+
+        assertThat(metadata.getFullCracInternalPackageName())
+            .isEqualTo("software.amazon.awssdk.services.query.internal.crac");
+    }
+}

codegen/src/test/java/software/amazon/awssdk/codegen/poet/crac/WarmUpProviderSpecTest.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file 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 software.amazon.awssdk.codegen.poet.crac;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static software.amazon.awssdk.codegen.poet.PoetMatchers.generatesTo;
+
+import org.junit.jupiter.api.Test;
+import software.amazon.awssdk.codegen.poet.ClassSpec;
+import software.amazon.awssdk.codegen.poet.ClientTestModels;
+
+public class WarmUpProviderSpecTest {
+
+    @Test
+    public void warmUpProvider() {
+        ClassSpec spec = new WarmUpProviderSpec(ClientTestModels.queryServiceModels());
+        assertThat(spec, generatesTo("warmup-provider.java"));
+    }
+}