jaxb-ri/runtime/impl/src/main/java/org/glassfish/jaxb/runtime/v2/runtime/reflect/opt/OptimizedTransducedAccessorFactory.java

/*
 * Copyright (c) 1997, 2020 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Distribution License v. 1.0, which is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

package org.glassfish.jaxb.runtime.v2.runtime.reflect.opt;

import org.glassfish.jaxb.core.v2.model.core.TypeInfo;
import org.glassfish.jaxb.runtime.v2.model.runtime.RuntimeClassInfo;
import org.glassfish.jaxb.runtime.v2.model.runtime.RuntimePropertyInfo;
import org.glassfish.jaxb.runtime.v2.runtime.reflect.Accessor;
import org.glassfish.jaxb.runtime.v2.runtime.reflect.TransducedAccessor;

import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.lang.reflect.Type;
import java.util.HashMap;
import java.util.Map;
import java.util.logging.Level;
import java.util.logging.Logger;

import static org.glassfish.jaxb.runtime.v2.bytecode.ClassTailor.toVMClassName;

/**
 * Prepares optimized {@link TransducedAccessor} from templates.
 *
 * @author Kohsuke Kawaguchi
 */
public abstract class OptimizedTransducedAccessorFactory {
    private OptimizedTransducedAccessorFactory() {} // no instantiation please

    // http://java.sun.com/docs/books/vmspec/2nd-edition/html/ConstantPool.doc.html#75929
    // "same runtime package"

    private static final Logger logger = Logger.getLogger(OptimizedTransducedAccessorFactory.class.getName());

    private static final String fieldTemplateName;
    private static final String methodTemplateName;

    static {
        String s = TransducedAccessor_field_Byte.class.getName();
        fieldTemplateName = s.substring(0,s.length()-"Byte".length()).replace('.','/');

        s = TransducedAccessor_method_Byte.class.getName();
        methodTemplateName = s.substring(0,s.length()-"Byte".length()).replace('.','/');
    }

    /**
     * Gets the optimized {@link TransducedAccessor} if possible.
     *
     * @return null
     *      if for some reason it fails to create an optimized version.
     */
    public static final TransducedAccessor get(RuntimePropertyInfo prop) {
        if(OptimizedAccessorFactory.noOptimization){
            return null;
        }

        Accessor acc = prop.getAccessor();

        // consider using an optimized TransducedAccessor implementations.
        Class opt=null;

        TypeInfo<Type,Class> parent = prop.parent();
        if(!(parent instanceof RuntimeClassInfo))
            return null;
        
        Class dc = ((RuntimeClassInfo)parent).getClazz();
        String newClassName = toVMClassName(dc)+"_JaxbXducedAccessor_"+prop.getName();


        if(acc instanceof Accessor.FieldReflection) {
            // TODO: we also need to make sure that the default xducer is used.
            Accessor.FieldReflection racc = (Accessor.FieldReflection) acc;
            Field field = racc.f;

            int mods = field.getModifiers();
            if(Modifier.isPrivate(mods) || Modifier.isFinal(mods))
                // we can't access private fields.
                // TODO: think about how to improve this case
                return null;

            Class<?> t = field.getType();
            if(t.isPrimitive())
                opt = AccessorInjector.prepare( dc,
                    fieldTemplateName+suffixMap.get(t),
                    newClassName,
                    toVMClassName(Bean.class),
                    toVMClassName(dc),
                    "f_"+t.getName(),
                    field.getName() );
        }

        if(acc.getClass()==Accessor.GetterSetterReflection.class) {
            Accessor.GetterSetterReflection gacc = (Accessor.GetterSetterReflection) acc;

            if(gacc.getter==null || gacc.setter==null)
                return null;    // incomplete

            Class<?> t = gacc.getter.getReturnType();

            if(Modifier.isPrivate(gacc.getter.getModifiers())
            || Modifier.isPrivate(gacc.setter.getModifiers()))
                // we can't access private methods.
                return null;


            if(t.isPrimitive())
                opt = AccessorInjector.prepare( dc,
                    methodTemplateName+suffixMap.get(t),
                    newClassName,
                    toVMClassName(Bean.class),
                    toVMClassName(dc),
                    "get_"+t.getName(),
                    gacc.getter.getName(),
                    "set_"+t.getName(),
                    gacc.setter.getName());
        }

        if(opt==null)
            return null;

        logger.log(Level.FINE,"Using optimized TransducedAccessor for "+prop.displayName());


        try {
            return (TransducedAccessor)opt.newInstance();
        } catch (InstantiationException e) {
            logger.log(Level.INFO,"failed to load an optimized TransducedAccessor",e);
        } catch (IllegalAccessException e) {
            logger.log(Level.INFO,"failed to load an optimized TransducedAccessor",e);
        } catch (SecurityException e) {
            logger.log(Level.INFO,"failed to load an optimized TransducedAccessor",e);
        }
        return null;
    }

    private static final Map<Class,String> suffixMap = new HashMap<Class, String>();

    static {
        suffixMap.put(Byte.TYPE,"Byte");
        suffixMap.put(Short.TYPE,"Short");
        suffixMap.put(Integer.TYPE,"Integer");
        suffixMap.put(Long.TYPE,"Long");
        suffixMap.put(Boolean.TYPE,"Boolean");
        suffixMap.put(Float.TYPE,"Float");
        suffixMap.put(Double.TYPE,"Double");
    }

}