// Copyright 2016 Yahoo Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
package com.yahoo.jdisc.application;
import com.google.common.collect.ImmutableSet;
import com.google.inject.*;
import com.google.inject.spi.DefaultElementVisitor;
import com.google.inject.spi.Element;
import com.google.inject.spi.Elements;
import com.yahoo.jdisc.Container;
import org.osgi.framework.Bundle;
import java.util.*;
import java.util.logging.Logger;
/**
* This is a repository of {@link Module}s. An instance of this class is owned by the {@link ContainerBuilder}, and is
* used to configure the set of Modules that eventually form the {@link Injector} of the active {@link Container}.
*
* @author Simon Thoresen
*/
public class GuiceRepository implements Iterable {
private static final Logger log = Logger.getLogger(GuiceRepository.class.getName());
private final Map> modules = new LinkedHashMap<>();
private Injector injector;
public GuiceRepository(Module... modules) {
installAll(Arrays.asList(modules));
}
public Injector activate() {
return getInjector();
}
public List installAll(Bundle bundle, Iterable moduleNames) throws ClassNotFoundException {
List lst = new LinkedList<>();
for (String moduleName : moduleNames) {
lst.add(install(bundle, moduleName));
}
return lst;
}
public Module install(Bundle bundle, String moduleName) throws ClassNotFoundException {
log.finer("Installing Guice module '" + moduleName + "'.");
Class> namedClass = bundle.loadClass(moduleName);
Class moduleClass = ContainerBuilder.safeClassCast(Module.class, namedClass);
Module module = getInstance(moduleClass);
install(module);
return module;
}
public void installAll(Iterable extends Module> modules) {
for (Module module : modules) {
install(module);
}
}
public void install(Module module) {
modules.put(module, Elements.getElements(module));
injector = null;
}
public void uninstallAll(Iterable extends Module> modules) {
for (Module module : modules) {
uninstall(module);
}
}
public void uninstall(Module module) {
modules.remove(module);
injector = null;
}
public Injector getInjector() {
if (injector == null) {
injector = Guice.createInjector(createModule());
}
return injector;
}
public T getInstance(Key key) {
return getInjector().getInstance(key);
}
public T getInstance(Class type) {
return getInjector().getInstance(type);
}
public Collection collection() { return ImmutableSet.copyOf(modules.keySet()); }
@Override
public Iterator iterator() {
return collection().iterator();
}
private Module createModule() {
List allElements = new LinkedList<>();
for (List moduleElements : modules.values()) {
allElements.addAll(moduleElements);
}
ElementCollector collector = new ElementCollector();
for (ListIterator it = allElements.listIterator(allElements.size()); it.hasPrevious(); ) {
it.previous().acceptVisitor(collector);
}
return Elements.getModule(collector.elements);
}
private static class ElementCollector extends DefaultElementVisitor {
final Set> seenKeys = new HashSet<>();
final List elements = new LinkedList<>();
@Override
public Boolean visit(Binding binding) {
if (seenKeys.add(binding.getKey())) {
elements.add(binding);
}
return Boolean.TRUE;
}
@Override
public Boolean visitOther(Element element) {
elements.add(element);
return Boolean.TRUE;
}
}
}