| /* |
| * Copyright (c) 2010-2017 BSI Business Systems Integration AG. |
| * 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: |
| * BSI Business Systems Integration AG - initial API and implementation |
| */ |
| /* |
| * Copyright (c) 2010-2015 BSI Business Systems Integration AG. |
| * 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: |
| * BSI Business Systems Integration AG - initial API and implementation |
| ******************************************************************************/ |
| package org.eclipse.scout.rt.platform; |
| |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.HashSet; |
| import java.util.List; |
| import java.util.Set; |
| import java.util.concurrent.locks.ReadWriteLock; |
| import java.util.concurrent.locks.ReentrantReadWriteLock; |
| |
| import org.eclipse.scout.rt.platform.index.AbstractMultiValuesIndex; |
| import org.eclipse.scout.rt.platform.index.IMultiValueIndex; |
| import org.eclipse.scout.rt.platform.index.IndexedStore; |
| import org.eclipse.scout.rt.platform.util.IRegistrationHandle; |
| import org.eclipse.scout.rt.platform.util.TypeCastUtility; |
| |
| /** |
| * A registry for beans implementing an interface with one generic type parameter, and which allows to lookup beans by |
| * its generic parameter type. |
| */ |
| public class TypeParameterBeanRegistry<BEAN> { |
| |
| protected final ReadWriteLock m_lock = new ReentrantReadWriteLock(); |
| |
| protected final Class<BEAN> m_beanType; |
| |
| protected final IndexedStore<BeanRegistration<BEAN>> m_inventory = new IndexedStore<>(); |
| protected final IMultiValueIndex<Class<?>, BeanRegistration<BEAN>> m_genericTypeIndex; |
| protected final Set<Class<?>> m_computedLookupTypes = Collections.synchronizedSet(new HashSet<>()); |
| |
| public TypeParameterBeanRegistry(final Class<BEAN> beanType) { |
| m_beanType = beanType; |
| |
| // Register the index to lookup beans by their generic parameter type, or by a super type of that generic parameter type. |
| m_genericTypeIndex = m_inventory.registerIndex(new AbstractMultiValuesIndex<Class<?>, BeanRegistration<BEAN>>() { |
| |
| @Override |
| protected Set<Class<?>> calculateIndexesFor(final BeanRegistration<BEAN> beanRegistration) { |
| final Set<Class<?>> indexValues = new HashSet<>(); |
| indexValues.add(beanRegistration.getGenericTypeParameter()); |
| indexValues.addAll(beanRegistration.getLazyLookupSubTypes()); |
| return indexValues; |
| } |
| }); |
| } |
| |
| /** |
| * Registers the given beans. |
| * |
| * @return A token representing the registration of the given beans. This token can later be used to unregister the |
| * beans. |
| */ |
| public IRegistrationHandle registerBeans(final List<BEAN> beans) { |
| final List<IRegistrationHandle> registrations = new ArrayList<>(); |
| |
| for (final BEAN bean : beans) { |
| registrations.add(registerBean(bean)); |
| } |
| |
| return () -> { |
| for (final IRegistrationHandle registration : registrations) { |
| registration.dispose(); |
| } |
| }; |
| } |
| |
| /** |
| * Registers the given bean by using its (first) generic type parameter as key. |
| * |
| * @return A token representing the registration of the given bean. This token can later be used to unregister the |
| * bean. |
| */ |
| public IRegistrationHandle registerBean(final BEAN bean) { |
| final Class genericTypeParameter = TypeCastUtility.getGenericsParameterClass(bean.getClass(), m_beanType); |
| return registerBean(bean, genericTypeParameter); |
| } |
| |
| /** |
| * Registers the given bean using the given {@code genericTypeParameter} as key. |
| * |
| * @return A token representing the registration of the given bean. This token can later be used to unregister the |
| * bean. |
| */ |
| public IRegistrationHandle registerBean(final BEAN bean, final Class<?> genericTypeParameter) { |
| m_computedLookupTypes.clear(); |
| |
| m_lock.writeLock().lock(); |
| try { |
| final BeanRegistration<BEAN> beanRegistration = new BeanRegistration<>(bean, genericTypeParameter); |
| |
| // Add the bean to the inventory. Thereby, the indexes are computed for that element. |
| m_inventory.add(beanRegistration); |
| |
| return () -> m_inventory.remove(beanRegistration); |
| } |
| finally { |
| m_lock.writeLock().unlock(); |
| } |
| } |
| |
| /** |
| * Returns all beans with the given generic type parameter, or which are declared with a super type of that parameter. |
| * <p> |
| * The beans are returned in the original order (see {@link #registerBeans(Class, List)}). |
| * </p> |
| * |
| * @param lookupType |
| * generic parameter type, not <code>null</code>. |
| */ |
| public List<BEAN> getBeans(final Class<?> lookupType) { |
| updateLookupTypeHierarchyIndex(lookupType); |
| |
| m_lock.readLock().lock(); |
| try { |
| final List<BEAN> beans = new ArrayList<>(); |
| for (final BeanRegistration<BEAN> registration : m_genericTypeIndex.get(lookupType)) { |
| beans.add(registration.getBean()); |
| } |
| return beans; |
| } |
| finally { |
| m_lock.readLock().unlock(); |
| } |
| } |
| |
| /** |
| * Registers the given lookup type with beans which have a generic type parameter that is a super type of the given |
| * lookup type. |
| * <p> |
| * This is done only the first time a lookup for that lookup type is done. |
| */ |
| protected void updateLookupTypeHierarchyIndex(final Class<?> lookupType) { |
| if (m_computedLookupTypes.contains(lookupType)) { |
| return; |
| } |
| |
| m_lock.writeLock().lock(); |
| try { |
| if (m_computedLookupTypes.contains(lookupType)) { |
| return; // double checked locking |
| } |
| |
| for (final BeanRegistration<BEAN> element : m_inventory.values()) { |
| if (element.getGenericTypeParameter().isAssignableFrom(lookupType)) { |
| element.registerLazyLookupSubType(lookupType); |
| |
| // Replace the element in the inventory to update the index. |
| m_inventory.remove(element); |
| m_inventory.add(element); |
| } |
| } |
| m_computedLookupTypes.add(lookupType); |
| } |
| finally { |
| m_lock.writeLock().unlock(); |
| } |
| } |
| |
| protected static class BeanRegistration<T> { |
| |
| private final T m_bean; |
| private final Class<?> m_genericTypeParameter; |
| |
| private final Set<Class<?>> m_lazyLookupSubTypes; |
| |
| public BeanRegistration(final T bean, final Class<?> genericTypeParameter) { |
| m_bean = bean; |
| m_genericTypeParameter = genericTypeParameter; |
| m_lazyLookupSubTypes = new HashSet<>(); |
| } |
| |
| public void registerLazyLookupSubType(final Class<?> lookupType) { |
| m_lazyLookupSubTypes.add(lookupType); |
| } |
| |
| public T getBean() { |
| return m_bean; |
| } |
| |
| /** |
| * Returns the generic bean type. |
| */ |
| public Class<?> getGenericTypeParameter() { |
| return m_genericTypeParameter; |
| } |
| |
| /** |
| * Returns the sub-types of the bean's generic type parameter. Those sub types are only populated upon a bean lookup |
| * for such a sub type, and which is remembered to speed up subsequent lookups. |
| */ |
| public Set<Class<?>> getLazyLookupSubTypes() { |
| return m_lazyLookupSubTypes; |
| } |
| } |
| } |