/*
* Copyright (c) 1998-2011 Caucho Technology -- all rights reserved
*
* This file is part of Resin(R) Open Source
*
* Each copy or derived work must preserve the copyright notice and this
* notice unmodified.
*
* Resin Open Source is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* Resin Open Source 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, or any warranty
* of NON-INFRINGEMENT. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with Resin Open Source; if not, write to the
*
* Free Software Foundation, Inc.
* 59 Temple Place, Suite 330
* Boston, MA 02111-1307 USA
*
* @author Scott Ferguson
*/
package com.caucho.loader;
import java.io.IOException;
import java.lang.ref.WeakReference;
import java.security.CodeSource;
import java.util.logging.Level;
import java.util.logging.Logger;
import com.caucho.inject.Module;
import com.caucho.make.DependencyContainer;
import com.caucho.util.Alarm;
import com.caucho.util.ByteBuffer;
import com.caucho.util.JniTroubleshoot;
import com.caucho.util.L10N;
import com.caucho.util.QDate;
import com.caucho.vfs.Depend;
import com.caucho.vfs.Dependency;
import com.caucho.vfs.JarPath;
import com.caucho.vfs.Path;
import com.caucho.vfs.PersistentDependency;
import com.caucho.vfs.ReadStream;
/**
* Describes a cached loaded class entry.
*/
@Module
public class ClassEntry implements Dependency {
private static final L10N L = new L10N(ClassEntry.class);
private static final Logger log
= Logger.getLogger(ClassEntry.class.getName());
private static boolean _hasJNIReload;
private static boolean _hasAnnotations;
private static final JniTroubleshoot _jniTroubleshoot;
private DynamicClassLoader _loader;
private String _name;
private Path _classPath;
private PersistentDependency _depend;
private boolean _classIsModified;
private Path _sourcePath;
private long _sourceLastModified;
private long _sourceLength;
private ClassPackage _classPackage;
private CodeSource _codeSource;
private WeakReference<Class<?>> _clRef;
/**
* Create a loaded class entry
*
* @param name the classname
* @param sourcePath path to the source Java file
* @param classPath path to the compiled class file
*/
public ClassEntry(DynamicClassLoader loader,
String name, Path sourcePath,
Path classPath,
CodeSource codeSource)
{
_loader = loader;
_name = name;
_classPath = classPath;
setDependPath(classPath);
if (sourcePath != null && ! sourcePath.equals(classPath)) {
_sourcePath = sourcePath;
_sourceLastModified = sourcePath.getLastModified();
_sourceLength = sourcePath.getLength();
}
_codeSource = codeSource;
}
/**
* Create a loaded class entry
*
* @param name the classname
* @param sourcePath path to the source Java file
* @param classPath path to the compiled class file
*/
public ClassEntry(Loader loader,
String name, Path sourcePath,
Path classPath)
{
this(loader.getClassLoader(), name, sourcePath, classPath,
loader.getCodeSource(classPath));
}
public String getName()
{
return _name;
}
/**
* returns the class loader.
*/
public DynamicClassLoader getClassLoader()
{
return _loader;
}
public CodeSource getCodeSource()
{
return _codeSource;
}
public Path getSourcePath()
{
return _sourcePath;
}
/**
* Sets the depend path.
*/
protected void setDependPath(Path dependPath)
{
if (dependPath instanceof JarPath)
_depend = ((JarPath) dependPath).getDepend();
else
_depend = new Depend(dependPath);
}
/**
* Adds the dependencies, returning true if it's adding itself.
*/
protected boolean addDependencies(DependencyContainer container)
{
if (_classPath instanceof JarPath) {
container.add(_depend);
return false;
}
else if (_hasJNIReload) {
container.add(this);
return true;
}
else if (_sourcePath == null) {
container.add(_depend);
return false;
}
else {
container.add(this);
return true;
}
}
public void setSourceLength(long length)
{
_sourceLength = length;
}
public void setSourceLastModified(long lastModified)
{
_sourceLastModified = lastModified;
}
public ClassPackage getClassPackage()
{
return _classPackage;
}
public void setClassPackage(ClassPackage pkg)
{
_classPackage = pkg;
}
/**
* Returns true if the source file has been modified.
*/
@Override
public boolean isModified()
{
if (_depend.isModified()) {
if (log.isLoggable(Level.FINE))
log.fine("class modified: " + _depend);
return reloadIsModified();
}
else if (_sourcePath == null) {
return false;
}
else if (_sourcePath.getLastModified() != _sourceLastModified) {
if (log.isLoggable(Level.FINE))
log.fine("source modified time: " + _sourcePath +
" old:" + QDate.formatLocal(_sourceLastModified) +
" new:" + QDate.formatLocal(_sourcePath.getLastModified()));
if (! compileIsModified()) {
return false;
}
boolean isModified = reloadIsModified();
return isModified;
}
else if (_sourcePath.getLength() != _sourceLength) {
if (log.isLoggable(Level.FINE))
log.fine("source modified length: " + _sourcePath +
" old:" + _sourceLength +
" new:" + _sourcePath.getLength());
if (! compileIsModified())
return false;
return reloadIsModified();
}
else {
return false;
}
}
/**
* Returns true if the source file has been modified.
*/
public boolean logModified(Logger log)
{
if (_depend.logModified(log)) {
return true;
}
else if (_sourcePath == null)
return false;
else if (_sourcePath.getLastModified() != _sourceLastModified) {
log.info("source modified time: " + _sourcePath +
" old:" + QDate.formatLocal(_sourceLastModified) +
" new:" + QDate.formatLocal(_sourcePath.getLastModified()));
return true;
}
else if (_sourcePath.getLength() != _sourceLength) {
log.info("source modified length: " + _sourcePath +
" old:" + _sourceLength +
" new:" + _sourcePath.getLength());
return true;
}
else {
return false;
}
}
/**
* Returns true if the compile doesn't avoid the dependency.
*/
public boolean compileIsModified()
{
return true;
}
/**
* Returns true if the reload doesn't avoid the dependency.
*/
public boolean reloadIsModified()
{
if (_classIsModified) {
return true;
}
if (! _hasJNIReload || ! _classPath.canRead()) {
return true;
}
try {
long length = _classPath.getLength();
Class<?> cl = _clRef != null ? _clRef.get() : null;
if (cl == null) {
return false;
}
if (cl.isAnnotationPresent(RequireReload.class))
return true;
ReadStream is = _classPath.openRead();
byte []bytecode = new byte[(int) length];
try {
is.readAll(bytecode, 0, bytecode.length);
} finally {
is.close();
}
int result = reloadNative(cl, bytecode, 0, bytecode.length);
if (result != 0) {
_classIsModified = true;
return true;
}
setDependPath(_classPath);
if (_sourcePath != null) {
_sourceLastModified = _sourcePath.getLastModified();
_sourceLength = _sourcePath.getLength();
}
log.info("Reloading " + cl.getName());
return false;
} catch (Exception e) {
log.log(Level.WARNING, e.toString(), e);
_classIsModified = true;
return true;
}
}
/**
* Returns the path to the class file.
*/
public Path getClassPath()
{
return _classPath;
}
public Class<?> getEntryClass()
{
return _clRef != null ? _clRef.get() : null;
}
public void setEntryClass(Class<?> cl)
{
_clRef = new WeakReference<Class<?>>(cl);
}
/**
* preload actions.
*/
public void preLoad()
throws ClassNotFoundException
{
}
/**
* Loads the contents of the class file into the buffer.
*/
public void load(ByteBuffer buffer)
throws IOException
{
synchronized (this) {
Path classPath = getClassPath();
buffer.clear();
int retry = 3;
for (int i = 0; i < retry; i++) {
long length = -1;
ReadStream is = classPath.openRead();
try {
length = classPath.getLength();
long lastModified = classPath.getLastModified();
if (length < 0)
throw new IOException("class loading failed because class file '" + classPath + "' does not have a positive length. Possibly the file has been overwritten");
buffer.setLength((int) length);
int results = is.readAll(buffer.getBuffer(), 0, (int) length);
if (results == length
&& length == classPath.getLength()
&& lastModified == classPath.getLastModified()) {
return;
}
log.warning(L.l("{0}: class file length mismatch expected={1} received={2}. The class file may have been modified concurrently.",
this, length, results));
} finally {
is.close();
}
}
}
}
/**
* post-load actions.
*/
public boolean postLoad()
{
return false;
}
public static boolean isReloadEnabled()
{
return _hasJNIReload;
}
public String toString()
{
if (_sourcePath == null)
return getClass().getSimpleName() + "[" + _classPath + "]";
else
return getClass().getSimpleName() + "[" + _classPath + ", src=" + _sourcePath + "]";
}
public static native boolean canReloadNative();
public static native int reloadNative(Class<?> cl,
byte []bytes, int offset, int length);
class ReloadThread implements Runnable {
private volatile boolean _isDone;
public boolean isDone()
{
return _isDone;
}
public void run()
{
}
}
static {
JniTroubleshoot jniTroubleshoot = null;
try {
System.loadLibrary("resin_os");
_hasJNIReload = canReloadNative();
if (Alarm.isTest()) {
// skip logging for test
}
else if (_hasJNIReload)
log.config("In-place class redefinition (HotSwap) is available.");
else
log.config("In-place class redefinition (HotSwap) is not available. In-place class reloading during development requires a compatible JDK and -Xdebug.");
jniTroubleshoot = new JniTroubleshoot(ClassEntry.class, "resin_os");
}
catch (Throwable e) {
jniTroubleshoot = new JniTroubleshoot(ClassEntry.class, "resin_os", e);
}
_jniTroubleshoot = jniTroubleshoot;
_jniTroubleshoot.log();
}
}