/*******************************************************************************
* Copyright (c) 2005, 2008 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.osgi.internal.loader.buddy;
import java.io.IOException;
import java.net.URL;
import java.util.*;
import org.eclipse.osgi.internal.loader.BundleLoader;
import org.eclipse.osgi.internal.loader.BundleLoaderProxy;
import org.eclipse.osgi.service.resolver.BundleDescription;
/**
* DependentPolicy is an implementation of a buddy policy.
* It is responsible for looking up a class in the dependents of the bundle
* to which this policy is attached to.
*/
public class DependentPolicy implements IBuddyPolicy {
BundleLoader buddyRequester;
int lastDependentOfAdded = -1; //remember the index of the bundle for which we last added the dependent
List allDependents = null; //the list of all dependents known so far
public DependentPolicy(BundleLoader requester) {
buddyRequester = requester;
//Initialize with the first level of dependent the list
allDependents = new ArrayList();
basicAddImmediateDependents(buddyRequester.getBundle().getBundleDescription());
//If there is no dependent, reset to null
if (allDependents.size() == 0)
allDependents = null;
}
public Class loadClass(String name) {
if (allDependents == null)
return null;
Class result = null;
//size may change, so we must check it every time
for (int i = 0; i < allDependents.size() && result == null; i++) {
BundleDescription searchedBundle = (BundleDescription) allDependents.get(i);
try {
BundleLoaderProxy proxy = buddyRequester.getLoaderProxy(searchedBundle);
if (proxy == null)
continue;
result = proxy.getBundleLoader().findClass(name);
} catch (ClassNotFoundException e) {
if (result == null)
addDependent(i, searchedBundle);
}
}
return result;
}
private synchronized void addDependent(int i, BundleDescription searchedBundle) {
if (i > lastDependentOfAdded) {
lastDependentOfAdded = i;
basicAddImmediateDependents(searchedBundle);
}
}
public URL loadResource(String name) {
if (allDependents == null)
return null;
URL result = null;
//size may change, so we must check it every time
for (int i = 0; i < allDependents.size() && result == null; i++) {
BundleDescription searchedBundle = (BundleDescription) allDependents.get(i);
BundleLoaderProxy proxy = buddyRequester.getLoaderProxy(searchedBundle);
if (proxy == null)
continue;
result = proxy.getBundleLoader().findResource(name);
if (result == null) {
addDependent(i, searchedBundle);
}
}
return result;
}
public Enumeration loadResources(String name) {
if (allDependents == null)
return null;
Enumeration results = null;
//size may change, so we must check it every time
for (int i = 0; i < allDependents.size(); i++) {
BundleDescription searchedBundle = (BundleDescription) allDependents.get(i);
try {
BundleLoaderProxy proxy = buddyRequester.getLoaderProxy(searchedBundle);
if (proxy == null)
continue;
results = BundleLoader.compoundEnumerations(results, proxy.getBundleLoader().findResources(name));
addDependent(i, searchedBundle);
} catch (IOException e) {
//Ignore and keep looking
}
}
return results;
}
private void basicAddImmediateDependents(BundleDescription root) {
BundleDescription[] dependents = root.getDependents();
for (int i = 0; i < dependents.length; i++) {
BundleDescription toAdd = dependents[i];
if (toAdd.getHost() == null && !allDependents.contains(toAdd)) {
allDependents.add(toAdd);
}
}
}
}