org.sonar.javascript.model.VisitorsDispatcher Maven / Gradle / Ivy
/*
* SonarQube JavaScript Plugin
* Copyright (C) 2011 SonarSource and Eriks Nukis
* [email protected]
*
* This program 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 3 of the License, or (at your option) any later version.
*
* This program 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 program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02
*/
package org.sonar.javascript.model;
import com.google.common.base.Throwables;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import javax.annotation.Nullable;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.List;
import java.util.Map;
import java.util.Set;
public class VisitorsDispatcher {
private final List visitors;
private final Set visitorClasses;
private final Map> visitMethods = Maps.newHashMap();
private final Map> leaveMethods = Maps.newHashMap();
public VisitorsDispatcher(List visitors) {
this.visitors = visitors;
ImmutableSet.Builder visitorClassesBuilder = ImmutableSet.builder();
for (Object visitor : visitors) {
visitorClassesBuilder.add(visitor.getClass());
}
this.visitorClasses = visitorClassesBuilder.build();
}
public void visit(Object node, Class nodeClass) {
invoke(visitMethods, false, nodeClass, node);
}
public void leave(Object node, Class nodeClass) {
invoke(leaveMethods, true, nodeClass, node);
}
private void invoke(Map> cache, boolean leave, Class nodeClass, Object node) {
Map methods = cache.get(nodeClass);
if (methods == null) {
methods = lookup(leave, nodeClass);
cache.put(nodeClass, methods);
}
for (Object visitor : leave ? Lists.reverse(visitors) : visitors) {
Method method = methods.get(visitor.getClass());
if (method != null) {
try {
method.invoke(visitor, node);
} catch (IllegalAccessException e) {
throw Throwables.propagate(e);
} catch (InvocationTargetException e) {
throw Throwables.propagate(e);
}
}
}
}
private Map lookup(boolean leave, Class nodeClass) {
ImmutableMap.Builder methodsBuilder = ImmutableMap.builder();
for (Class visitorClass : visitorClasses) {
Method method = lookup(visitorClass, leave ? "leave" : "visit", nodeClass);
if (method != null) {
methodsBuilder.put(visitorClass, method);
}
}
return methodsBuilder.build();
}
@Nullable
private static Method lookup(Class visitorClass, String methodName, Class nodeClass) {
try {
return visitorClass.getMethod(methodName, nodeClass);
} catch (NoSuchMethodException e) {
for (Class base : nodeClass.getInterfaces()) {
return lookup(visitorClass, methodName, base);
}
return null;
}
}
}