org.eclipse.osgi.internal.loader.buddy.DependentPolicy Maven / Gradle / Ivy
/*******************************************************************************
* Copyright (c) 2005, 2016 IBM Corporation and others.
*
* This program and the accompanying materials
* are made available under the terms of the Eclipse Public License 2.0
* which accompanies this distribution, and is available at
* https://www.eclipse.org/legal/epl-2.0/
*
* SPDX-License-Identifier: EPL-2.0
*
* 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.ArrayList;
import java.util.Enumeration;
import java.util.List;
import java.util.Set;
import org.eclipse.osgi.container.ModuleWire;
import org.eclipse.osgi.container.ModuleWiring;
import org.eclipse.osgi.internal.loader.BundleLoader;
import org.osgi.framework.namespace.BundleNamespace;
import org.osgi.framework.namespace.PackageNamespace;
/**
* 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(requester.getWiring());
//If there is no dependent, reset to null
if (allDependents.size() == 0)
allDependents = null;
}
@Override
public Class loadClass(String name) {
if (allDependents == null) {
return null;
}
//size may change, so we must check it every time
for (int i = 0; i < allDependents.size(); i++) {
ModuleWiring searchWiring = allDependents.get(i);
BundleLoader searchLoader = (BundleLoader) searchWiring.getModuleLoader();
if (searchLoader != null) {
Class result = searchLoader.findClassNoParentNoException(name);
if (result != null) {
return result;
}
addDependent(i, searchWiring);
}
}
return null;
}
private synchronized void addDependent(int i, ModuleWiring searchedWiring) {
if (i > lastDependentOfAdded) {
lastDependentOfAdded = i;
basicAddImmediateDependents(searchedWiring);
}
}
@Override
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++) {
ModuleWiring searchWiring = allDependents.get(i);
BundleLoader searchLoader = (BundleLoader) searchWiring.getModuleLoader();
if (searchLoader != null) {
result = searchLoader.findResource(name);
if (result == null) {
addDependent(i, searchWiring);
}
}
}
return result;
}
@Override
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++) {
ModuleWiring searchWiring = allDependents.get(i);
BundleLoader searchLoader = (BundleLoader) searchWiring.getModuleLoader();
if (searchLoader != null) {
try {
results = BundleLoader.compoundEnumerations(results, searchLoader.findResources(name));
addDependent(i, searchWiring);
} catch (IOException e) {
//Ignore and keep looking
}
}
}
return results;
}
@Override
public void addListResources(Set results, String path, String filePattern, int options) {
if (allDependents == null) {
return;
}
// size may change, so we must check it every time
for (int i = 0; i < allDependents.size(); i++) {
ModuleWiring searchWiring = allDependents.get(i);
results.addAll(searchWiring.listResources(path, filePattern, options));
addDependent(i, searchWiring);
}
}
private void basicAddImmediateDependents(ModuleWiring wiring) {
List providedWires = wiring.getProvidedModuleWires(null);
if (providedWires != null) {
for (ModuleWire wire : providedWires) {
String namespace = wire.getRequirement().getNamespace();
if (PackageNamespace.PACKAGE_NAMESPACE.equals(namespace) || BundleNamespace.BUNDLE_NAMESPACE.equals(namespace)) {
ModuleWiring dependent = wire.getRequirerWiring();
if (!allDependents.contains(dependent)) {
allDependents.add(dependent);
}
}
}
}
}
}