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package org.glassfish.flashlight.impl.client;
/**
* @author Mahesh Kannan
* Started: Jul 20, 2008
* @author Byron Nevins, August 2009
*/
import com.sun.enterprise.util.SystemPropertyConstants;
import org.glassfish.flashlight.provider.FlashlightProbe;
import org.glassfish.flashlight.provider.ProbeRegistry;
import org.objectweb.asm.AnnotationVisitor;
import org.objectweb.asm.ClassWriter;
import org.objectweb.asm.Label;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.Type;
import org.objectweb.asm.commons.GeneratorAdapter;
import org.objectweb.asm.commons.Method;
import java.io.File;
import java.io.FileOutputStream;
import java.io.PrintStream;
import java.lang.reflect.InvocationTargetException;
import java.security.PrivilegedActionException;
import java.security.ProtectionDomain;
import java.util.Collection;
public class BtraceClientGenerator {
private BtraceClientGenerator() {
// all static class -- no instances allowed
}
public static byte[] generateBtraceClientClassData(int clientID, Collection<FlashlightProbe> probes) {
// create a unique name. It does not matter what the name is.
String generatedClassName = "com/sun/btrace/flashlight/BTrace_Flashlight_" + clientID;
//Start of writing a class using ASM, which will be our BTrace Client
int cwFlags = ClassWriter.COMPUTE_FRAMES + ClassWriter.COMPUTE_MAXS;
ClassWriter cw = new ClassWriter(cwFlags);
//Define the access identifiers for the BTrace Client class
int access = Opcodes.ACC_PUBLIC + Opcodes.ACC_FINAL;
cw.visit(Opcodes.V1_5, access, generatedClassName, null,
"java/lang/Object", null);
//Need a @OnMethod annotation, so prepare your Annotation Visitor for that
AnnotationVisitor av = cw.visitAnnotation("Lcom/sun/btrace/annotations/BTrace;", true);
//Iterate through the probes, so you will create one method for each probe
int methodCounter = 0;
for (FlashlightProbe probe : probes) {
//Preparing the class method header and params (type) for @OnMethod annotation
String typeDesc = "void ";
String methodDesc = "void __" + probe.getProviderJavaMethodName() + "__" + clientID + "_" + methodCounter + "_";
methodDesc += "(";
typeDesc += "(";
String delim = "";
String typeDelim = "";
Class[] paramTypes = probe.getParamTypes();
for (int index = 0; index < paramTypes.length; index++) {
Class paramType = paramTypes[index];
methodDesc += delim + paramType.getName();
// Dont add the param type for type desc, if self is the first index
if (!(probe.hasSelf() && (index == 0))) {
typeDesc += typeDelim + paramType.getName();
typeDelim = ",";
}
delim = ", ";
}
methodDesc += ")";
typeDesc += ")";
//Creating the class method
Method m = Method.getMethod(methodDesc);
GeneratorAdapter gen = new GeneratorAdapter(Opcodes.ACC_PUBLIC + Opcodes.ACC_STATIC, m, null, null, cw);
// Add the @Self annotation
if (probe.hasSelf()) {
String[] paramNames = probe.getProbeParamNames();
for (int index = 0; index < paramNames.length; index++) {
if (paramNames[index].equalsIgnoreCase(FlashlightProbe.SELF)) {
AnnotationVisitor paramVisitor = gen.visitParameterAnnotation(index, "Lcom/sun/btrace/annotations/Self;", true);
paramVisitor.visitEnd();
}
}
}
//Add the @OnMethod annotation to this method
av = gen.visitAnnotation("Lcom/sun/btrace/annotations/OnMethod;", true);
av.visit("clazz", "" + probe.getProviderClazz().getName());
av.visit("method", probe.getProviderJavaMethodName());
av.visit("type", typeDesc);
av.visitEnd();
//Add the body
gen.push(probe.getId());
gen.loadArgArray();
gen.invokeStatic(Type.getType(
ProbeRegistry.class), Method.getMethod("void invokeProbe(int, Object[])"));
gen.returnValue();
gen.endMethod();
methodCounter++;
}
BtraceClientGenerator.generateConstructor(cw);
cw.visitEnd();
byte[] classData = cw.toByteArray();
writeClass(classData, generatedClassName);
return classData;
}
private static void writeClass(byte[] classData, String generatedClassName) {
// only do this if we are in "debug" mode
// if(Boolean.parseBoolean(System.getenv("AS_DEBUG")) == false)
// return;
System.out.println("**** Generated BTRACE Client " + generatedClassName);
try {
int index = generatedClassName.lastIndexOf('/');
String rootPath = System.getProperty(SystemPropertyConstants.INSTALL_ROOT_PROPERTY) +
File.separator + "lib" + File.separator;
String fileName = rootPath + generatedClassName.substring(index + 1) + ".class";
//System.out.println("***ClassFile: " + fileName);
File file = new File(fileName);
FileOutputStream fos = new FileOutputStream(file);
fos.write(classData);
fos.flush();
fos.close();
} catch (Exception ex) {
ex.printStackTrace();
}
}
private static void generateConstructor(ClassWriter cw) {
Method m = Method.getMethod("void <init> ()");
GeneratorAdapter gen = new GeneratorAdapter(Opcodes.ACC_PUBLIC, m, null, null, cw);
gen.loadThis();
gen.invokeConstructor(Type.getType(Object.class), m);
//return the value from constructor
gen.returnValue();
gen.endMethod();
}
}
/**** Example generated class (bnevins, August 2009)
*
* package com.sun.btrace.flashlight.org.glassfish.web.admin.monitor;
import com.sun.btrace.annotations.BTrace;
import com.sun.btrace.annotations.OnMethod;
import javax.servlet.Servlet;
import org.glassfish.flashlight.provider.ProbeRegistry;
@BTrace
public final class ServletStatsProvider_BTrace_7_
{
@OnMethod(clazz="org.glassfish.web.admin.monitor.ServletProbeProvider", method="servletInitializedEvent", type="void (javax.servlet.Servlet, java.lang.String, java.lang.String)")
public static void __servletInitializedEvent__7_0_(Servlet paramServlet, String paramString1, String paramString2)
{
ProbeRegistry.invokeProbe(78, new Object[] { paramServlet, paramString1, paramString2 });
}
@OnMethod(clazz="org.glassfish.web.admin.monitor.ServletProbeProvider", method="servletDestroyedEvent", type="void (javax.servlet.Servlet, java.lang.String, java.lang.String)")
public static void __servletDestroyedEvent__7_1_(Servlet paramServlet, String paramString1, String paramString2)
{
ProbeRegistry.invokeProbe(79, new Object[] { paramServlet, paramString1, paramString2 });
}
}
*/