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- /*
- * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This code is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation.
- *
- * This code 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 General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- *
- */
- package com.github.dcevm;
-
- import org.objectweb.asm.ClassReader;
- import org.objectweb.asm.ClassWriter;
- import org.objectweb.asm.Type;
-
- import java.io.*;
- import java.lang.instrument.UnmodifiableClassException;
- import java.net.URL;
- import java.util.HashMap;
- import java.util.Hashtable;
- import java.util.Map;
- import java.util.regex.Matcher;
- import java.util.regex.Pattern;
-
- /**
- * @author Thomas Wuerthinger
- * @author Kerstin Breiteneder
- * @author Christoph Wimberger
- * @author Ivan Dubrov
- */
- public class HotSwapTool {
-
- /**
- * Prefix for the version number in the class name. The class bytes are modified that this string including
- * the following number is removed. This means that e.g. A___2 is treated as A anywhere in the source code. This is introduced
- * to make the IDE not complain about multiple defined classes.
- */
- public static final Pattern VERSION_PATTERN = Pattern.compile("___([0-9]+)");
- public static final Pattern VERSION_MATCH = Pattern.compile(".*(___([0-9]+))$");
- private static final String CLASS_FILE_SUFFIX = ".class";
- private static Map<Class<?>, Integer> currentVersion = new Hashtable<Class<?>, Integer>();
- private static Redefiner redefiner;
- private static int redefinitionCount;
- private static long totalTime;
-
- static {
- try {
- //redefiner = new JDIRedefiner(4000);
- redefiner = new InstrumentationRedefiner();
- } catch (Exception e) {
- throw new IllegalStateException(e);
- }
- }
-
- /**
- * Returns the current version of the inner classes of a specified outer class.
- *
- * @param baseClass the outer class whose version is queried
- * @return the version of the inner classes of the specified outer class
- */
- public static int getCurrentVersion(Class<?> baseClass) {
- if (!currentVersion.containsKey(baseClass)) {
- currentVersion.put(baseClass, 0);
- }
- return currentVersion.get(baseClass);
- }
-
- /**
- * Performs an explicit shutdown and disconnects from the VM.
- */
- public static void shutdown() throws IOException {
- redefiner.close();
- redefiner = null;
- }
-
- private static Map<Class<?>, byte[]> buildRedefinitionMap(Map<String, File> classes) throws IOException, ClassNotFoundException {
- // Collect rename rules
- // Also, makes sure all classes are loaded in the VM, before they are redefined
- final Map<String, String> typeMappings = new HashMap<String, String>();
- for (String name : classes.keySet()) {
- Class<?> clazz = Class.forName(name); // FIXME: classloader?
- ClassRedefinitionPolicy policy = clazz.getAnnotation(ClassRedefinitionPolicy.class);
- Class<?> replacement = (policy != null && policy.alias() != ClassRedefinitionPolicy.NoClass.class) ?
- policy.alias() : clazz;
- typeMappings.put(Type.getInternalName(clazz), stripVersion(Type.getInternalName(replacement)));
-
- }
-
- Map<Class<?>, byte[]> classesMap = new HashMap<Class<?>, byte[]>();
- for (File file : classes.values()) {
- loadAdaptedClass(file, typeMappings, classesMap);
- }
- return classesMap;
- }
-
- private static void loadAdaptedClass(File file, Map<String, String> typeMappnigs, Map<Class<?>, byte[]> result) throws IOException, ClassNotFoundException {
-
- ClassWriter writer = new ClassWriter(ClassWriter.COMPUTE_FRAMES | ClassWriter.COMPUTE_MAXS);
- TestClassAdapter adapter = new TestClassAdapter(writer, typeMappnigs);
-
- InputStream in = new FileInputStream(file);
- try {
- new ClassReader(in).accept(adapter, ClassReader.EXPAND_FRAMES);
- } finally {
- try {
- in.close();
- } catch (IOException e) {
- // Ignore.
- }
- }
- byte[] bytes = writer.toByteArray();
- String className = adapter.getClassName().replace('/', '.');
- result.put(Class.forName(className), bytes); // FIXME: ClassLoader...
- }
-
- /**
- * Redefines all inner classes of a outer class to a specified version. Inner classes who do not have a particular
- * representation for a version remain unchanged.
- *
- * @param outerClass the outer class whose inner classes should be redefined
- * @param versionNumber the target version number
- */
- public static void toVersion(Class<?> outerClass, int versionNumber, Class<?>... extraClasses) {
- assert versionNumber >= 0;
-
- if (versionNumber == getCurrentVersion(outerClass)) {
- // Nothing to do!
- return;
- }
-
- Map<String, File> files = findClassesWithVersion(outerClass, versionNumber);
-
- for (Class<?> extra : extraClasses) {
- if (parseClassVersion(extra.getSimpleName()) == versionNumber) {
- String packageName = extra.getPackage().getName().replace('.', '/');
- URL url = extra.getClassLoader().getResource(packageName);
- if (url == null) {
- throw new IllegalArgumentException("Cannot find URL corresponding to the package '" + packageName + "'");
- }
- File file = new File(url.getFile(), extra.getSimpleName() + ".class");
- files.put(extra.getName(), file);
- }
- }
-
- try {
- Map<Class<?>, byte[]> map = buildRedefinitionMap(files);
-
- long startTime = System.currentTimeMillis();
- redefiner.redefineClasses(map);
- long curTime = System.currentTimeMillis() - startTime;
- totalTime += curTime;
- redefinitionCount++;
-
- } catch (UnmodifiableClassException e) {
- throw new UnsupportedOperationException(e);
- } catch (ClassNotFoundException e) {
- throw new RuntimeException("Cannot redefine classes", e);
- } catch (IOException e) {
- throw new RuntimeException("Cannot redefine classes", e);
- }
-
- setCurrentVersion(outerClass, versionNumber);
- }
-
- private static Map<String, File> findClassesWithVersion(Class<?> baseClass, int version) {
- Map<String, File> classes = new HashMap<String, File>();
-
- String packageName = baseClass.getPackage().getName().replace('.', '/');
- URL url = baseClass.getClassLoader().getResource(packageName);
- if (url == null) {
- throw new IllegalArgumentException("Cannot find URL corresponding to the package '" + packageName + "'");
- }
- File folder = new File(url.getFile());
- for (File f : folder.listFiles(IsClassFile.INSTANCE)) {
- String simpleName = f.getName().substring(0, f.getName().length() - CLASS_FILE_SUFFIX.length());
- String name = baseClass.getPackage().getName() + '.' + simpleName;
-
- if (isInnerClass(name, baseClass) && parseClassVersion(simpleName) == version) {
- classes.put(name, f);
- }
- }
- return classes;
- }
-
- private enum IsClassFile implements FilenameFilter {
- INSTANCE;
-
- @Override
- public boolean accept(File dir, String name) {
- return name.endsWith(CLASS_FILE_SUFFIX);
- }
- }
-
- private static boolean isInnerClass(String name, Class<?> baseClass) {
- return name.startsWith(baseClass.getName() + "$");
- }
-
- private static void setCurrentVersion(Class<?> baseClass, int value) {
- currentVersion.put(baseClass, value);
- }
-
- /**
- * Parse version of the class from the class name. Classes are named in the form of [Name]___[Version]
- */
- private static int parseClassVersion(String simpleName) {
- Matcher m = VERSION_MATCH.matcher(simpleName);
- return m.matches() ? Integer.valueOf(m.group(2)) : 0;
- }
-
- private static String stripVersion(String className) {
- Matcher m = VERSION_MATCH.matcher(className);
- if (m.matches()) {
- return className.substring(0, m.start(1)) + className.substring(m.end(1));
- } else {
- return className;
- }
- }
-
- public static void resetTimings() {
- redefinitionCount = 0;
- totalTime = 0;
- }
-
- public static int getRedefinitionCount() {
- return redefinitionCount;
- }
-
- public static long getTotalTime() {
- return totalTime;
- }
- }
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