/*
* JBoss, Home of Professional Open Source
* Copyright 2009-10 Red Hat and individual contributors
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*
* @authors Andrew Dinn
*/
package org.jboss.byteman.agent;
import org.jboss.byteman.rule.Rule;
import org.jboss.byteman.rule.type.TypeHelper;
import java.util.ArrayList;
import java.util.List;
import java.io.StringWriter;
import java.io.PrintWriter;
/**
* details of a single rule obtained from a rule file. RuleScript instances are stored in the script repository
* attached to the transformer. They are used to generate Rule instances at transform time. The RuleScript contains
* a list of Transforms which detail failed or successful transforms performed using the script.
*/
public class RuleScript
{
/**
* the name of the rule from which this script is derived
*/
private String name;
/**
* the name supplied in the CLASS or INTERFACE clause of the rule identifying which class(es)
* triggers should be injected into
*/
private String targetClass;
/**
* true if the target is an interface or false if the target is a class, in the former case the
* rule should be injected into methods of classes which implement the interface.
*/
private boolean isInterface;
/**
* the name of the method of the target class or interface into which the rule should be injected
*/
private String targetMethod;
/**
* true if the rule should be injected into overriding implementations of the target method false
* if it should only be injected into the implementation defined by the target class or, in the
* case of an interface rule, by the class directly implementing the target interface
*/
private boolean isOverride;
/**
* the name of a class whose public instance methods define the built-in methods available for use
* in the rule body
*/
private String targetHelper;
/**
* the details of the IMPORT lines
*/
private String[] imports;
/**
* identifies the location in the method if the trigger point at which the rule code should be injected.
* note that for an AT EXIT rule there may be multiple trigger points.
*/
private Location targetLocation;
/**
* the text of the rule's BIND IF and DO clauses which are parsed using a grammar based parser
*/
private String ruleText;
/**
* this is set to true if the rule is dynamically deleted or updated so as to inhibit execution of
* trigger code between the delete/update and recompilation/reinstatement of the affected bytecode.
*/
private boolean deleted;
/**
* the line number at which the rule text starts
*/
private int line;
/**
* the name of the file from which the rule has been loaded, if defined, or some suitable dummy string if it
* was noti obtained from a file
*/
private String file;
/**
* true if this rule should be compiled to bytecode otherwise false
*/
private final boolean compileToBytecode;
/**
* a list of records identifying contexts in which the rule has been applied.
*/
private List<Transform> transformed;
/**
* standard constructor for a rule
* @param name the name of the rule
* @param targetClass the name of the class or interface to which the rule applies
* @param isInterface true if the ruel applies to an interface false if it appies ot a class
* @param isOverride true if the rule should inject down class hierarchies false if it should inly inject into direct implementations
* @param targetMethod the name of the method to which the rule applies
* @param targetHelper the name of the helper class to be used
* @param imports the list of imports for the module system
* @param targetLocation description of where the rule should be injected
* @param ruleText the body of the rule as text including the BIND, IF and DO clasue
* @param line the line at which the rule starts in it's rule script
* @param file the path to the file containing the rule
* @param compileToBytecode true if the rule should be compiled otherwise false
*/
public RuleScript(String name, String targetClass, boolean isInterface, boolean isOverride, String targetMethod, String targetHelper, String[] imports, Location targetLocation, String ruleText, int line, String file, boolean compileToBytecode)
{
this.name = name;
this.targetClass = targetClass;
this.isInterface = isInterface;
this.isOverride = isOverride;
this.targetMethod = targetMethod;
this.targetHelper = targetHelper;
this.imports = imports;
this.targetLocation = (targetLocation != null ? targetLocation : Location.create(LocationType.ENTRY, ""));
this.ruleText = ruleText;
this.line = line;
this.file = file;
this.compileToBytecode = compileToBytecode;
this.transformed = new ArrayList<Transform>();
}
public String getName() {
return name;
}
public String getTargetClass() {
return targetClass;
}
public boolean isInterface() {
return isInterface;
}
public String getTargetHelper() {
return targetHelper;
}
public String[] getImports() {
return imports;
}
public String getTargetMethod() {
return targetMethod;
}
public boolean isOverride() {
return isOverride;
}
public Location getTargetLocation() {
return targetLocation;
}
public String getRuleText() {
return ruleText;
}
public int getLine()
{
return line;
}
public String getFile()
{
return file;
}
public boolean isCompileToBytecode() { return compileToBytecode; }
/**
* getter for list of transforms applied for this script. must be called synchronized on the script.
* @return the list of transforms
*/
public List<Transform> getTransformed()
{
return transformed;
}
/**
* return a count of the number of transforms applied for this script. must be called synchronized on the script.
* @return the size of the list of transforms
*/
public int getTransformedCount()
{
return (transformed != null ? transformed.size() : 0);
}
/**
* invoked by the scriptmanager when a rule is redefined to inhibit further transformations via this script
* @return the previous setting of deleted
*/
public synchronized boolean setDeleted()
{
if (!deleted) {
deleted = true;
return false;
}
return true;
}
/**
* called when indexing a script to ensure that it has not already been deleted. it must only be called
* when synchronized on the script. This avoids a race where a script can be added by thread A, deleted by
* thread B, unindexed -- unsuccessfully -- by thread B then indexed by thread A
* @return the previous setting of deleted
*/
public boolean isDeleted()
{
return deleted;
}
/**
* record the fact that an error was thrown when attempting to transform a given class using this rule script
* @param loader the loader of the class for which injection was attempted
* @param internalClassName the internal Java name of the class
* @param th the Throwable reocrding details of the failure
* @return true if the failure was recorded false if not
*/
public synchronized boolean recordFailedTransform(ClassLoader loader, String internalClassName, Throwable th)
{
return recordTransform(loader, internalClassName, null, null, null, th);
}
/**
* record the fact that a trigger call has been successfully installed into bytecode associated with a specific
* class and loader and a corresponding rule instance been installed
* @param loader the loader of the class for which injection was attempted
* @param internalClassName the internal Java name of the class
* @param triggerMethodName the name of the method injected into
* @param desc the descriptor of the method injected into
* @param rule the rule which was injected
* @return true if the successful injection was recorded false if not
*/
public synchronized boolean recordMethodTransform(ClassLoader loader, String internalClassName, String triggerMethodName, String desc, Rule rule)
{
return recordTransform(loader, internalClassName, triggerMethodName, desc, rule, null);
}
/**
* record the fact that a trigger call has failed to install into bytecode associated with a specific
* class and loader
* @param loader the loader of the class for which injection was attempted
* @param internalClassName the internal Java name of the class
* @param triggerMethodName the name of the method injected into
* @param desc the descriptor of the method injected into
* @param rule the rule which was injected
* @param th throwable generated during the attempt to parse the rule text or inject code at the trigger point
* @return true if the successful injection was recorded false if not
*/
public synchronized boolean recordTransform(ClassLoader loader, String internalClassName, String triggerMethodName, String desc, Rule rule, Throwable th)
{
if (deleted) {
return false;
}
String fullMethodName = null;
if (triggerMethodName != null) {
fullMethodName = triggerMethodName + TypeHelper.internalizeDescriptor(desc);
}
// and install the transform in the list
transformed.add(new Transform(loader, internalClassName, fullMethodName, rule, th));
return true;
}
/**
* check whether a rule has been used to transform a specific class. this can be used when
* rules are redefined to decide whether or not a class needs to be retransformed. Note that
* it must only be called after the script has been deleted by calling setDeleted.
* @param clazz the class for which a transform is being sought.
* @return true if the class has been transformed using this script otherwise false.
*/
public synchronized boolean hasTransform(Class<?> clazz)
{
ClassLoader loader = clazz.getClassLoader();
if (loader == null) {
loader = ClassLoader.getSystemClassLoader();
}
int count = getTransformedCount();
for (int i = 0; i < count; i++) {
Transform transform = transformed.get(i);
if (transform.getLoader() == loader) {
return true;
}
}
return false;
}
/**
* record the fact that a rule has been compiled with or without success
* @param triggerClass the name of the trigger class to which the rule is attached
* @param loader the classloader of the trigger class
* @param successful true if the rule compiled successfully and false if it suffered from parse,
* type or compile errors
* @param detail text decribing more details of the compilation outcome
*/
public synchronized void recordCompile(String triggerClass, ClassLoader loader, boolean successful, String detail)
{
int count = getTransformedCount();
for (int i = 0; i < count; i++) {
Transform transform = transformed.get(i);
if (transform.getLoader() == loader) {
transform.setCompiled(successful, detail);
}
}
}
/**
* uninstall any rules associated with this script. this is called after marking the script as
* deleted and regenerating the methods for any associated transformed class to ensure that it does
* not cause a rule trigger call to fail.
*/
public synchronized void purge()
{
if (transformed != null) {
int count = transformed.size();
for (int i = 0; i < count; i++) {
Transform transform = transformed.get(i);
Rule rule = transform.getRule();
if (rule != null) {
rule.purge();
}
}
}
}
public String toString()
{
StringWriter stringWriter = new StringWriter();
PrintWriter writer = new PrintWriter(stringWriter);
writeTo(writer);
writer.flush();
return stringWriter.toString();
}
public void writeTo(PrintWriter writer)
{
writer.print("# File ");
writer.print(file);
writer.print(" line ");
writer.println(line);
writer.print("RULE ");
writer.println(name);
if (isInterface) {
writer.print("INTERFACE ");
} else {
writer.print("CLASS ");
}
if (isOverride) {
writer.print("^");
}
writer.println(targetClass);
writer.print("METHOD ");
writer.println(targetMethod);
if (imports != null) {
for (int i = 0; i < imports.length ; i++) {
writer.print("IMPORT ");
writer.println(imports[i]);
}
}
if (targetHelper != null) {
writer.print("HELPER ");
writer.println(targetHelper);
}
if (compileToBytecode) {
writer.write("COMPILE\n");
} else {
writer.write("NOCOMPILE\n");
}
writer.println(targetLocation.toString());
writer.println(ruleText);
writer.println("ENDRULE");
}
}