io.syncframework.optimizer.OInterceptorStaticMethodVisitor.java Source code

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Here is the source code for io.syncframework.optimizer.OInterceptorStaticMethodVisitor.java

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/*
 * Copyright 2016 SyncObjects Ltda.
 * 
 * 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 io.syncframework.optimizer;

import org.objectweb.asm.Label;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.Type;

/**
 * @author dfroz
 */
public class OInterceptorStaticMethodVisitor extends MethodVisitor {
    private OInterceptorReflector reflector;

    public OInterceptorStaticMethodVisitor(MethodVisitor mv, OInterceptorReflector reflector) {
        super(Opcodes.ASM5, mv);
        this.reflector = reflector;
    }

    public void visitInsn(int opcode) {
        if (opcode != Opcodes.RETURN) {
            mv.visitInsn(opcode);
            return;
        }

        Label start = new Label();
        Label l1 = new Label();
        Label l2 = new Label();

        mv.visitCode();
        mv.visitTryCatchBlock(start, l1, l2, "java/lang/Throwable");

        /* 
         * _asParameters = new HashMap<String,Class<?>>() 
         */
        {
            mv.visitLabel(start);
            mv.visitTypeInsn(Opcodes.NEW, "java/util/HashMap");
            mv.visitInsn(Opcodes.DUP);
            mv.visitMethodInsn(Opcodes.INVOKESPECIAL, "java/util/HashMap", "<init>", "()V", false);
            mv.visitFieldInsn(Opcodes.PUTSTATIC, reflector.getClazzInternalName(), "_asParameters",
                    "Ljava/util/Map;");
        }
        /*
         * _asParameters.put("name", Type.class);
         */
        for (String name : reflector.getParameters().keySet()) {
            Label l = new Label();
            mv.visitLabel(l);
            mv.visitFieldInsn(Opcodes.GETSTATIC, reflector.getClazzInternalName(), "_asParameters",
                    "Ljava/util/Map;");
            mv.visitLdcInsn(name);
            mv.visitLdcInsn(Type.getType(reflector.getParameters().get(name)));
            mv.visitMethodInsn(Opcodes.INVOKEINTERFACE, "java/util/Map", "put",
                    "(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;", true);
            mv.visitInsn(Opcodes.POP);
        }

        /* 
         * _asConverters = new HashMap<String,Class<?>>() 
         */
        {
            Label l = new Label();
            mv.visitLabel(l);
            mv.visitTypeInsn(Opcodes.NEW, "java/util/HashMap");
            mv.visitInsn(Opcodes.DUP);
            mv.visitMethodInsn(Opcodes.INVOKESPECIAL, "java/util/HashMap", "<init>", "()V", false);
            mv.visitFieldInsn(Opcodes.PUTSTATIC, reflector.getClazzInternalName(), "_asConverters",
                    "Ljava/util/Map;");
        }
        /*
         * _asConverters.put("name", Type.class);
         */
        for (String name : reflector.getParameters().keySet()) {
            if (reflector.getConverters().get(name) != null) {
                Class<?> converter = reflector.getConverters().get(name);
                Label l = new Label();
                mv.visitLabel(l);
                mv.visitFieldInsn(Opcodes.GETSTATIC, reflector.getClazzInternalName(), "_asConverters",
                        "Ljava/util/Map;");
                mv.visitLdcInsn(name);
                mv.visitLdcInsn(Type.getType(converter));
                mv.visitMethodInsn(Opcodes.INVOKEINTERFACE, "java/util/Map", "put",
                        "(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;", true);
                mv.visitInsn(Opcodes.POP);
            }
        }

        /*
         * }
         * catch(Throwable t) {
         *    throw t;
         * }
         */
        Label throwableStart = new Label();
        Label throwableEnd = new Label();

        mv.visitLabel(l1);
        mv.visitJumpInsn(Opcodes.GOTO, throwableEnd);

        mv.visitLabel(l2);
        mv.visitFrame(Opcodes.F_SAME1, 0, null, 1, new Object[] { "java/lang/Throwable" });
        mv.visitVarInsn(Opcodes.ASTORE, 0);

        mv.visitLabel(throwableStart);
        mv.visitVarInsn(Opcodes.ALOAD, 0);
        mv.visitInsn(Opcodes.ATHROW);

        mv.visitLabel(throwableEnd);
        mv.visitFrame(Opcodes.F_SAME, 0, null, 0, null);
        mv.visitInsn(Opcodes.RETURN);
        mv.visitLocalVariable("t", "Ljava/lang/Throwable;", null, throwableStart, throwableEnd, 0);
    }
}