com.mgmtp.perfload.agent.hook.ServletApiHookMethodVisitor Maven / Gradle / Ivy
/*
* Copyright (c) 2013 mgm technology partners GmbH
*
* 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.mgmtp.perfload.agent.hook;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Type;
import org.objectweb.asm.commons.AdviceAdapter;
/**
* An ASM {@link MethodVisitor} that weave the {@link HookManager} into a method's byte code.
*
* @author rnaegele
*/
public class ServletApiHookMethodVisitor extends AdviceAdapter {
private static final String ENTER_HOOK_DESC = new StringBuilder(100)
.append('(')
.append(Type.getDescriptor(Object.class))
.append(Type.getDescriptor(Object[].class))
.append(")V")
.toString();
private static final String EXIT_HOOK_DESC = "()V";
private static final String OWNER = HookManager.class.getName().replace('.', '/');
public ServletApiHookMethodVisitor(final int access, final String methodName, final String desc, final MethodVisitor mv) {
super(ASM4, mv, access, methodName, desc);
}
@Override
protected void onMethodEnter() {
loadThis();
loadArgArray();
mv.visitMethodInsn(INVOKESTATIC, OWNER, "enterServletApiHook", ENTER_HOOK_DESC);
}
@Override
protected void onMethodExit(final int opcode) {
mv.visitMethodInsn(INVOKESTATIC, OWNER, "exitServletApiHook", EXIT_HOOK_DESC);
}
}