package org.drools.rule;
/*
* Copyright 2005 JBoss Inc
*
* 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.
*/
import java.io.ByteArrayInputStream;
import java.io.Externalizable;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.security.ProtectionDomain;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import org.drools.RuntimeDroolsException;
import org.drools.common.DroolsObjectInput;
import org.drools.spi.Wireable;
import org.drools.util.StringUtils;
public class JavaDialectRuntimeData
implements
DialectRuntimeData,
Externalizable {
/**
*
*/
private static final long serialVersionUID = 400L;
private static final ProtectionDomain PROTECTION_DOMAIN;
private Map invokerLookups;
private Map store;
private DialectRuntimeRegistry registry;
private transient PackageClassLoader classLoader;
private transient CompositeClassLoader rootClassLoader;
private boolean dirty;
private List<String> wireList = Collections.<String> emptyList();
static {
PROTECTION_DOMAIN = (ProtectionDomain) AccessController.doPrivileged( new PrivilegedAction() {
public Object run() {
return JavaDialectRuntimeData.class.getProtectionDomain();
}
} );
}
public JavaDialectRuntimeData() {
this.invokerLookups = new HashMap();
this.store = new HashMap();
this.dirty = false;
}
/**
* Handles the write serialization of the PackageCompilationData. Patterns in Rules may reference generated data which cannot be serialized by
* default methods. The PackageCompilationData holds a reference to the generated bytecode. The generated bytecode must be restored before any Rules.
*
*/
public void writeExternal(ObjectOutput stream) throws IOException {
stream.writeInt( this.store.size() );
for ( Iterator it = this.store.entrySet().iterator(); it.hasNext(); ) {
Entry entry = (Entry) it.next();
stream.writeObject( entry.getKey() );
stream.writeObject( entry.getValue() );
}
stream.writeInt( this.invokerLookups.size() );
for ( Iterator it = this.invokerLookups.entrySet().iterator(); it.hasNext(); ) {
Entry entry = (Entry) it.next();
stream.writeObject( entry.getKey() );
stream.writeObject( entry.getValue() );
}
}
/**
* Handles the read serialization of the PackageCompilationData. Patterns in Rules may reference generated data which cannot be serialized by
* default methods. The PackageCompilationData holds a reference to the generated bytecode; which must be restored before any Rules.
* A custom ObjectInputStream, able to resolve classes against the bytecode, is used to restore the Rules.
*
*/
public void readExternal(ObjectInput stream) throws IOException,
ClassNotFoundException {
DroolsObjectInput droolsStream = (DroolsObjectInput) stream;
for ( int i = 0, length = stream.readInt(); i < length; i++ ) {
this.store.put( stream.readObject(),
stream.readObject() );
}
for ( int i = 0, length = stream.readInt(); i < length; i++ ) {
this.invokerLookups.put( stream.readObject(),
stream.readObject() );
}
// mark it as dirty, so that it reloads everything.
this.dirty = true;
}
public void onAdd(DialectRuntimeRegistry registry,
CompositeClassLoader rootClassLoader) {
this.registry = registry;
this.rootClassLoader = rootClassLoader;
this.classLoader = new PackageClassLoader( this,
this.rootClassLoader );
this.rootClassLoader.addClassLoader( this.classLoader );
}
public void onRemove() {
this.rootClassLoader.removeClassLoader( this.classLoader );
}
public void onBeforeExecute() {
if ( isDirty() ) {
reload();
} else if ( !this.wireList.isEmpty() ) {
try {
// wire all remaining resources
for ( String resourceName : this.wireList ) {
wire( convertResourceToClassName( resourceName ) );
}
} catch ( Exception e ) {
throw new RuntimeDroolsException( "Unable to wire up JavaDialect",
e );
}
}
this.wireList.clear();
}
public DialectRuntimeData clone(DialectRuntimeRegistry registry,
CompositeClassLoader rootClassLoader) {
DialectRuntimeData cloneOne = new JavaDialectRuntimeData();
cloneOne.merge( registry,
this );
cloneOne.onAdd( registry,
rootClassLoader );
return cloneOne;
}
public void merge(DialectRuntimeRegistry registry,
DialectRuntimeData newData) {
this.registry = registry;
JavaDialectRuntimeData newJavaData = (JavaDialectRuntimeData) newData;
// First update the binary files
// @todo: this probably has issues if you add classes in the incorrect order - functions, rules, invokers.
for ( String resourceName : newJavaData.list() ) {
write( resourceName,
newJavaData.read( resourceName ) );
// // no need to wire, as we already know this is done in a merge
// if ( getStore().put( resourceName,
// newJavaData.read( resourceName ) ) != null ) {
// // we are updating an existing class so reload();
// this.dirty = true;
// }
// if ( this.dirty == false ) {
// // only build up the wireList if we aren't going to reload
// this.wireList.add( resourceName );
// }
}
// if ( this.dirty ) {
// // no need to keep wireList if we are going to reload;
// this.wireList.clear();
// }
// Add invokers
putAllInvokers( newJavaData.getInvokers() );
}
public boolean isDirty() {
return this.dirty;
}
public void setDirty(boolean dirty) {
this.dirty = dirty;
}
protected Map getStore() {
if ( store == null ) {
store = new HashMap();
}
return store;
}
public ClassLoader getClassLoader() {
return this.classLoader;
}
public void removeRule(Package pkg,
Rule rule) {
final String consequenceName = rule.getConsequence().getClass().getName();
// check for compiled code and remove if present.
if ( remove( consequenceName ) ) {
removeClasses( rule.getLhs() );
// Now remove the rule class - the name is a subset of the consequence name
remove( consequenceName.substring( 0,
consequenceName.indexOf( "ConsequenceInvoker" ) ) );
}
}
public void removeFunction(Package pkg,
Function function) {
remove( pkg.getName() + "." + StringUtils.ucFirst( function.getName() ) );
}
private void removeClasses(final ConditionalElement ce) {
if ( ce instanceof GroupElement ) {
final GroupElement group = (GroupElement) ce;
for ( final Iterator it = group.getChildren().iterator(); it.hasNext(); ) {
final Object object = it.next();
if ( object instanceof ConditionalElement ) {
removeClasses( (ConditionalElement) object );
} else if ( object instanceof Pattern ) {
removeClasses( (Pattern) object );
}
}
} else if ( ce instanceof EvalCondition ) {
remove( ((EvalCondition) ce).getEvalExpression().getClass().getName() );
}
}
private void removeClasses(final Pattern pattern) {
for ( final Iterator it = pattern.getConstraints().iterator(); it.hasNext(); ) {
final Object object = it.next();
if ( object instanceof PredicateConstraint ) {
remove( ((PredicateConstraint) object).getPredicateExpression().getClass().getName() );
} else if ( object instanceof ReturnValueConstraint ) {
remove( ((ReturnValueConstraint) object).getExpression().getClass().getName() );
}
}
}
public byte[] read(final String resourceName) {
byte[] bytes = null;
if ( !getStore().isEmpty() ) {
bytes = (byte[]) getStore().get( resourceName );
}
return bytes;
}
public void write(final String resourceName,
final byte[] clazzData) throws RuntimeDroolsException {
if ( getStore().put( resourceName,
clazzData ) != null ) {
this.dirty = true;
if ( !this.wireList.isEmpty() ) {
this.wireList.clear();
}
} else if ( !this.dirty ) {
try {
if ( this.wireList == Collections.<String> emptyList() ) {
this.wireList = new ArrayList<String>();
}
this.wireList.add( resourceName );
} catch ( final Exception e ) {
e.printStackTrace();
throw new RuntimeDroolsException( e );
}
}
}
public void wire(final String className) throws ClassNotFoundException,
InstantiationException,
IllegalAccessException {
final Object invoker = getInvokers().get( className );
wire( className,
invoker );
}
public void wire(final String className,
final Object invoker) throws ClassNotFoundException,
InstantiationException,
IllegalAccessException {
final Class clazz = this.rootClassLoader.loadClass( className );
if ( clazz != null ) {
if ( invoker instanceof Wireable ) {
((Wireable) invoker).wire( clazz.newInstance() );
}
//
//if ( invoker instanceof ReturnValueRestriction ) {
//((ReturnValueRestriction) invoker).setReturnValueExpression( (ReturnValueExpression) clazz.newInstance() );
//} else if ( invoker instanceof PredicateConstraint ) {
//((PredicateConstraint) invoker).setPredicateExpression( (PredicateExpression) clazz.newInstance() );
//} else if ( invoker instanceof EvalCondition ) {
//((EvalCondition) invoker).setEvalExpression( (EvalExpression) clazz.newInstance() );
//} else if ( invoker instanceof Accumulate ) {
//((Accumulate) invoker).setAccumulator( (Accumulator) clazz.newInstance() );
//} else if ( invoker instanceof Rule ) {
//((Rule) invoker).setConsequence( (Consequence) clazz.newInstance() );
//} else if ( invoker instanceof JavaAccumulatorFunctionExecutor ) {
//((JavaAccumulatorFunctionExecutor) invoker).setExpression( (ReturnValueExpression) clazz.newInstance() );
//} else if ( invoker instanceof DroolsAction ) {
//((DroolsAction) invoker).setMetaData( "Action",
// clazz.newInstance() );
//} else if ( invoker instanceof ReturnValueConstraintEvaluator ) {
//((ReturnValueConstraintEvaluator) invoker).setEvaluator( (ReturnValueEvaluator) clazz.newInstance() );
//}
} else {
throw new ClassNotFoundException( className );
}
}
public boolean remove(final String resourceName) throws RuntimeDroolsException {
getInvokers().remove( resourceName );
if ( getStore().remove( convertClassToResourcePath( resourceName ) ) != null ) {
this.wireList.remove( resourceName );
// we need to make sure the class is removed from the classLoader
// reload();
this.dirty = true;
return true;
}
return false;
}
public String[] list() {
String[] names = new String[getStore().size()];
int i = 0;
for ( Object object : getStore().keySet() ) {
names[i++] = (String) object;
}
return names;
}
/**
* This class drops the classLoader and reloads it. During this process it must re-wire all the invokeables.
* @throws RuntimeDroolsException
*/
public void reload() throws RuntimeDroolsException {
// drops the classLoader and adds a new one
this.rootClassLoader.removeClassLoader( this.classLoader );
this.classLoader = new PackageClassLoader( this,
this.rootClassLoader );
this.rootClassLoader.addClassLoader( this.classLoader );
// Wire up invokers
try {
for ( final Object object : getInvokers().entrySet() ) {
Entry entry = (Entry) object;
wire( (String) entry.getKey(),
entry.getValue() );
}
} catch ( final ClassNotFoundException e ) {
throw new RuntimeDroolsException( e );
} catch ( final InstantiationError e ) {
throw new RuntimeDroolsException( e );
} catch ( final IllegalAccessException e ) {
throw new RuntimeDroolsException( e );
} catch ( final InstantiationException e ) {
throw new RuntimeDroolsException( e );
}
this.dirty = false;
}
public void clear() {
getStore().clear();
getInvokers().clear();
reload();
}
public String toString() {
return this.getClass().getName() + getStore().toString();
}
public void putInvoker(final String className,
final Object invoker) {
getInvokers().put( className,
invoker );
}
public void putAllInvokers(final Map invokers) {
getInvokers().putAll( invokers );
}
public Map getInvokers() {
if ( this.invokerLookups == null ) {
this.invokerLookups = new HashMap();
}
return this.invokerLookups;
}
public void removeInvoker(final String className) {
getInvokers().remove( className );
}
public static class PackageClassLoader extends ClassLoader
implements
DroolsClassLoader {
private JavaDialectRuntimeData store;
CompositeClassLoader rootClassLoader;
public PackageClassLoader(JavaDialectRuntimeData store,
CompositeClassLoader rootClassLoader) {
super( rootClassLoader );
this.rootClassLoader = rootClassLoader;
this.store = store;
}
public Class fastFindClass(final String name) {
Class cls = findLoadedClass( name );
if ( cls == null ) {
final byte[] clazzBytes = this.store.read( convertClassToResourcePath( name ) );
if ( clazzBytes != null ) {
cls = defineClass( name,
clazzBytes,
0,
clazzBytes.length,
PROTECTION_DOMAIN );
}
}
return cls;
}
public synchronized Class loadClass(final String name,
final boolean resolve) throws ClassNotFoundException {
Class cls = fastFindClass( name );
if ( cls == null ) {
final ClassLoader parent = getParent();
if ( parent != null ) {
cls = Class.forName( name,
true,
parent );
}
}
if ( resolve && cls != null ) {
resolveClass( cls );
}
return cls;
}
protected Class findClass(final String name) throws ClassNotFoundException {
return fastFindClass( name );
}
public InputStream getResourceAsStream(final String name) {
final byte[] clsBytes = this.store.read( name );
if ( clsBytes != null ) {
return new ByteArrayInputStream( clsBytes );
}
return null;
}
}
/**
* Please do not use - internal
* org/my/Class.xxx -> org.my.Class
*/
public static String convertResourceToClassName(final String pResourceName) {
return stripExtension( pResourceName ).replace( '/',
'.' );
}
/**
* Please do not use - internal
* org.my.Class -> org/my/Class.class
*/
public static String convertClassToResourcePath(final String pName) {
return pName.replace( '.',
'/' ) + ".class";
}
/**
* Please do not use - internal
* org/my/Class.xxx -> org/my/Class
*/
public static String stripExtension(final String pResourceName) {
final int i = pResourceName.lastIndexOf( '.' );
final String withoutExtension = pResourceName.substring( 0,
i );
return withoutExtension;
}
}