com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodecUtil.java Source code

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Here is the source code for com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodecUtil.java

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// Copyright 2017 The Bazel Authors. 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.
// 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.google.devtools.build.lib.skyframe.serialization.autocodec;

import com.google.common.collect.ImmutableList;
import com.google.devtools.build.lib.skyframe.serialization.DeserializationContext;
import com.google.devtools.build.lib.skyframe.serialization.ObjectCodec;
import com.google.devtools.build.lib.skyframe.serialization.SerializationContext;
import com.google.devtools.build.lib.skyframe.serialization.SerializationException;
import com.google.protobuf.CodedInputStream;
import com.google.protobuf.CodedOutputStream;
import com.squareup.javapoet.ClassName;
import com.squareup.javapoet.MethodSpec;
import com.squareup.javapoet.ParameterizedTypeName;
import com.squareup.javapoet.TypeName;
import com.squareup.javapoet.TypeSpec;
import java.io.IOException;
import java.util.stream.Collectors;
import javax.annotation.processing.ProcessingEnvironment;
import javax.lang.model.element.Element;
import javax.lang.model.element.Modifier;
import javax.lang.model.element.TypeElement;
import javax.lang.model.type.TypeMirror;

/** Static utilities for AutoCodec processors. */
class AutoCodecUtil {
    // Synthesized classes will have `_AutoCodec` suffix added.
    private static final String GENERATED_CLASS_NAME_SUFFIX = "AutoCodec";
    static final Class<AutoCodec> ANNOTATION = AutoCodec.class;

    /**
     * Initializes a builder for a class of the appropriate type.
     *
     * @param encodedType type being serialized
     */
    static TypeSpec.Builder initializeCodecClassBuilder(TypeElement encodedType, ProcessingEnvironment env) {
        TypeSpec.Builder builder = TypeSpec.classBuilder(getCodecName(encodedType));
        return builder.addSuperinterface(ParameterizedTypeName.get(ClassName.get(ObjectCodec.class),
                TypeName.get(env.getTypeUtils().erasure(encodedType.asType()))));
    }

    static MethodSpec.Builder initializeGetEncodedClassMethod(TypeElement encodedType, ProcessingEnvironment env) {
        return MethodSpec.methodBuilder("getEncodedClass").addModifiers(Modifier.PUBLIC)
                .addAnnotation(Override.class).returns(ParameterizedTypeName.get(ClassName.get(Class.class),
                        TypeName.get(env.getTypeUtils().erasure(encodedType.asType()))));
    }

    /**
     * Initializes the deserialize method.
     *
     * @param encodedType type being serialized
     */
    static MethodSpec.Builder initializeSerializeMethodBuilder(TypeElement encodedType, ProcessingEnvironment env) {
        MethodSpec.Builder builder = MethodSpec.methodBuilder("serialize").addModifiers(Modifier.PUBLIC)
                .returns(void.class).addAnnotation(Override.class).addException(SerializationException.class)
                .addException(IOException.class).addParameter(SerializationContext.class, "context")
                .addParameter(TypeName.get(env.getTypeUtils().erasure(encodedType.asType())), "input")
                .addParameter(CodedOutputStream.class, "codedOut");
        return builder;
    }

    /**
     * Initializes the deserialize method.
     *
     * @param encodedType type being serialized
     */
    static MethodSpec.Builder initializeDeserializeMethodBuilder(TypeElement encodedType,
            ProcessingEnvironment env) {
        MethodSpec.Builder builder = MethodSpec.methodBuilder("deserialize").addModifiers(Modifier.PUBLIC)
                .returns(TypeName.get(env.getTypeUtils().erasure(encodedType.asType())))
                .addAnnotation(Override.class).addException(SerializationException.class)
                .addException(IOException.class).addParameter(DeserializationContext.class, "context")
                .addParameter(CodedInputStream.class, "codedIn");
        return builder;
    }

    /**
     * Returns a class name generated from the given {@code element}.
     *
     * <p>For {@code Foo.Bar} this is {@code Foo_Bar_suffix}.
     */
    static String getGeneratedName(Element element, String suffix) {
        ImmutableList.Builder<String> classNamesBuilder = new ImmutableList.Builder<>();
        classNamesBuilder.add(suffix);
        do {
            classNamesBuilder.add(element.getSimpleName().toString());
            element = element.getEnclosingElement();
        } while (element instanceof TypeElement);
        return classNamesBuilder.build().reverse().stream().collect(Collectors.joining("_"));
    }

    /**
     * Name of the generated codec class.
     *
     * <p>For {@code Foo.Bar} this is {@code Foo_Bar_AutoCodec}.
     */
    private static String getCodecName(Element element) {
        return getGeneratedName(element, GENERATED_CLASS_NAME_SUFFIX);
    }

    static TypeMirror getType(Class<?> clazz, ProcessingEnvironment env) {
        return env.getElementUtils().getTypeElement((clazz.getCanonicalName())).asType();
    }

    static boolean isSubType(TypeMirror type, Class<?> clazz, ProcessingEnvironment env) {
        return env.getTypeUtils().isSubtype(type, getType(clazz, env));
    }
}