1 /* 2 * Copyright (C) 2016 The Dagger Authors. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package dagger.grpc.server.processor; 18 19 import static com.google.auto.common.AnnotationMirrors.getAnnotationValue; 20 import static com.google.auto.common.GeneratedAnnotationSpecs.generatedAnnotationSpec; 21 import static com.google.auto.common.MoreElements.getAnnotationMirror; 22 import static com.google.common.base.CaseFormat.LOWER_CAMEL; 23 import static com.google.common.base.CaseFormat.UPPER_CAMEL; 24 25 import com.google.auto.common.MoreTypes; 26 import com.google.common.base.Joiner; 27 import com.squareup.javapoet.AnnotationSpec; 28 import com.squareup.javapoet.ClassName; 29 import dagger.grpc.server.ForGrpcService; 30 import dagger.grpc.server.GrpcService; 31 import dagger.grpc.server.processor.SourceGenerator.IoGrpc; 32 import java.util.Optional; 33 import javax.annotation.processing.Messager; 34 import javax.annotation.processing.ProcessingEnvironment; 35 import javax.lang.model.SourceVersion; 36 import javax.lang.model.element.AnnotationMirror; 37 import javax.lang.model.element.AnnotationValue; 38 import javax.lang.model.element.AnnotationValueVisitor; 39 import javax.lang.model.element.TypeElement; 40 import javax.lang.model.type.TypeMirror; 41 import javax.lang.model.util.Elements; 42 import javax.lang.model.util.SimpleAnnotationValueVisitor7; 43 import javax.lang.model.util.Types; 44 import javax.tools.Diagnostic.Kind; 45 46 class GrpcServiceModel { 47 48 private static final String GRPC_SERVICE_PARAMETER_NAME = "grpcClass"; 49 50 private final Types types; 51 private final Elements elements; 52 private final SourceVersion sourceVersion; 53 private final Messager messager; 54 final TypeElement serviceImplementation; 55 final ClassName serviceImplementationClassName; 56 final ClassName serviceDefinitionTypeName; 57 final ClassName proxyModuleName; 58 final ClassName serviceDefinitionTypeFactoryName; 59 final ClassName serviceModuleName; 60 final ClassName unscopedServiceModuleName; 61 GrpcServiceModel(ProcessingEnvironment processingEnv, TypeElement serviceImplementation)62 GrpcServiceModel(ProcessingEnvironment processingEnv, TypeElement serviceImplementation) { 63 this.types = processingEnv.getTypeUtils(); 64 this.elements = processingEnv.getElementUtils(); 65 this.sourceVersion = processingEnv.getSourceVersion(); 66 this.messager = processingEnv.getMessager(); 67 this.serviceImplementation = serviceImplementation; 68 this.serviceImplementationClassName = ClassName.get(serviceImplementation); 69 this.serviceDefinitionTypeName = peerClassWithSuffix("ServiceDefinition"); 70 this.serviceDefinitionTypeFactoryName = serviceDefinitionTypeName.nestedClass("Factory"); 71 this.proxyModuleName = peerClassWithSuffix("GrpcProxyModule"); 72 this.serviceModuleName = peerClassWithSuffix("GrpcServiceModule"); 73 this.unscopedServiceModuleName = peerClassWithSuffix("UnscopedGrpcServiceModule"); 74 } 75 76 /** 77 * Returns the name of a top-level class in the same package as the service implementation 78 * class, whose name is the simple name of the service implementation class and its enclosing 79 * classes, joined with underscores, and appended with {@code suffix}. 80 */ peerClassWithSuffix(String suffix)81 private ClassName peerClassWithSuffix(String suffix) { 82 return serviceImplementationClassName.peerClass( 83 Joiner.on('_').join(serviceImplementationClassName.simpleNames()) + suffix); 84 } 85 packageName()86 String packageName() { 87 return serviceImplementationClassName.packageName(); 88 } 89 validate()90 public boolean validate() { 91 AnnotationValue argument = 92 getAnnotationValue(grpcServiceAnnotation(), GRPC_SERVICE_PARAMETER_NAME); 93 return argument.accept( 94 new SimpleAnnotationValueVisitor7<Boolean, AnnotationValue>(false) { 95 @Override 96 public Boolean visitType(TypeMirror type, AnnotationValue value) { 97 return validateGrpcClass(type, value); 98 } 99 }, 100 argument); 101 } 102 103 private AnnotationMirror grpcServiceAnnotation() { 104 return getAnnotationMirror(serviceImplementation, GrpcService.class).get(); 105 } 106 107 /** Returns the gRPC service class declared by {@link GrpcService#grpcClass()}. */ 108 protected final TypeElement grpcClass() { 109 AnnotationValue argument = 110 getAnnotationValue(grpcServiceAnnotation(), GRPC_SERVICE_PARAMETER_NAME); 111 return GET_TYPE_ELEMENT_FROM_VALUE.visit(argument, argument); 112 } 113 114 /** 115 * Returns the annotation spec for the {@code @Generated} annotation to add to any 116 * type generated by this processor. 117 */ 118 protected final Optional<AnnotationSpec> generatedAnnotation() { 119 return generatedAnnotationSpec( 120 elements, 121 sourceVersion, 122 GrpcService.class, 123 String.format( 124 "@%s annotation on %s", 125 GrpcService.class.getCanonicalName(), serviceImplementationClassName)); 126 } 127 128 /** 129 * Returns the annotation spec for a {@link ForGrpcService} annotation whose value is the 130 * gRPC-generated service class. 131 */ 132 protected final AnnotationSpec forGrpcService() { 133 return AnnotationSpec.builder(ForGrpcService.class) 134 .addMember("value", "$T.class", grpcClass()) 135 .build(); 136 } 137 138 protected final String subcomponentServiceDefinitionMethodName() { 139 return UPPER_CAMEL.to(LOWER_CAMEL, simpleServiceName()) + "ServiceDefinition"; 140 } 141 142 private String simpleServiceName() { 143 return grpcClass().getSimpleName().toString().replaceFirst("Grpc$", ""); 144 } 145 146 private TypeElement serviceImplBase(TypeMirror service) { 147 ClassName serviceClassName = ClassName.get(MoreTypes.asTypeElement(service)); 148 ClassName serviceImplBaseName = serviceClassName.nestedClass(simpleServiceName() + "ImplBase"); 149 return elements.getTypeElement(serviceImplBaseName.toString()); 150 } 151 152 private boolean validateGrpcClass(TypeMirror type, AnnotationValue value) { 153 TypeElement serviceImplBase = serviceImplBase(type); 154 if (serviceImplBase == null || !types.isSubtype(serviceImplBase.asType(), bindableService())) { 155 messager.printMessage( 156 Kind.ERROR, 157 String.format("%s is not a gRPC service class", type), 158 serviceImplementation, 159 grpcServiceAnnotation(), 160 value); 161 return false; 162 } 163 if (!(types.isSubtype(serviceImplementation.asType(), serviceImplBase.asType()))) { 164 messager.printMessage( 165 Kind.ERROR, 166 String.format( 167 "%s must extend %s", serviceImplementation, serviceImplBase.getQualifiedName()), 168 serviceImplementation, 169 grpcServiceAnnotation(), 170 value); 171 return false; 172 } 173 return true; 174 } 175 176 private TypeMirror bindableService() { 177 return elements.getTypeElement(IoGrpc.BINDABLE_SERVICE.toString()).asType(); 178 } 179 180 static final AnnotationValueVisitor<TypeElement, AnnotationValue> GET_TYPE_ELEMENT_FROM_VALUE = 181 new SimpleAnnotationValueVisitor7<TypeElement, AnnotationValue>() { 182 @Override 183 public TypeElement visitType(TypeMirror t, AnnotationValue p) { 184 return MoreTypes.asTypeElement(t); 185 } 186 187 @Override 188 protected TypeElement defaultAction(Object o, AnnotationValue p) { 189 throw new IllegalArgumentException("Expected " + p + " to be a class"); 190 } 191 }; 192 } 193