Java tutorial
/* * Copyright 2016-present Open Networking Laboratory * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.onosproject.store.resource.impl; import com.google.common.base.MoreObjects; import com.google.common.collect.ImmutableSet; import com.google.common.collect.Sets; import org.onosproject.net.resource.DiscreteResource; import org.onosproject.net.resource.DiscreteResourceCodec; import org.onosproject.net.resource.DiscreteResourceId; import org.onosproject.net.resource.Resources; import java.util.LinkedHashMap; import java.util.LinkedHashSet; import java.util.Map; import java.util.Map.Entry; import java.util.Objects; import java.util.Optional; import java.util.Set; import java.util.stream.Collectors; import java.util.stream.Stream; /** * A set of discrete resources that can be encoded as integers. */ final class EncodableDiscreteResources implements DiscreteResources { private static final Codecs CODECS = Codecs.getInstance(); private final DiscreteResource parent; private final Map<Class<?>, EncodedDiscreteResources> map; private static Class<?> getClass(DiscreteResource resource) { return resource.valueAs(Object.class).map(Object::getClass).get(); } static DiscreteResources of(Set<DiscreteResource> resources) { if (resources.isEmpty()) { return DiscreteResources.empty(); } DiscreteResource parent = resources.iterator().next().parent().get(); return of(parent, resources); } static EncodableDiscreteResources of(DiscreteResource parent, Set<DiscreteResource> resources) { Map<Class<?>, Set<DiscreteResource>> grouped = resources.stream() .collect(Collectors.groupingBy(x -> getClass(x), Collectors.toCollection(LinkedHashSet::new))); Map<Class<?>, EncodedDiscreteResources> values = new LinkedHashMap<>(); for (Map.Entry<Class<?>, Set<DiscreteResource>> entry : grouped.entrySet()) { DiscreteResourceCodec<?> codec = CODECS.getCodec(entry.getKey()); values.put(entry.getKey(), EncodedDiscreteResources.of(entry.getValue(), codec)); } return new EncodableDiscreteResources(parent, values); } private static DiscreteResources of(DiscreteResource parent, Map<Class<?>, EncodedDiscreteResources> map) { if (isEmpty(map)) { return DiscreteResources.empty(); } return new EncodableDiscreteResources(parent, map); } private static boolean isEmpty(Map<Class<?>, EncodedDiscreteResources> map) { return map.values().stream().allMatch(EncodedDiscreteResources::isEmpty); } EncodableDiscreteResources(DiscreteResource parent, Map<Class<?>, EncodedDiscreteResources> map) { this.parent = parent; this.map = map; } @Override public Optional<DiscreteResource> lookup(DiscreteResourceId id) { if (!id.parent().filter(parent.id()::equals).isPresent()) { return Optional.empty(); } DiscreteResource resource = Resources.discrete(id).resource(); Class<?> cls = getClass(resource); return Optional.ofNullable(map.get(cls)).filter(x -> x.contains(resource)).map(x -> resource); } @Override public DiscreteResources difference(DiscreteResources other) { if (other instanceof EncodableDiscreteResources) { EncodableDiscreteResources cast = (EncodableDiscreteResources) other; Map<Class<?>, EncodedDiscreteResources> newMap = new LinkedHashMap<>(); for (Entry<Class<?>, EncodedDiscreteResources> e : this.map.entrySet()) { Class<?> key = e.getKey(); EncodedDiscreteResources thisValues = e.getValue(); EncodedDiscreteResources otherValues = cast.map.get(key); if (otherValues == null) { newMap.put(key, thisValues); continue; } EncodedDiscreteResources diff = thisValues.difference(otherValues); // omit empty resources from a new resource set // empty EncodedDiscreteResources can't deserialize due to // inability to reproduce a Class<?> instance from the serialized data if (diff.isEmpty()) { continue; } newMap.put(key, diff); } return of(parent, newMap); } else if (other instanceof EmptyDiscreteResources) { return this; } return DiscreteResources.of(Sets.difference(values(), other.values())); } @Override public boolean isEmpty() { return isEmpty(map); } @Override public boolean containsAny(Set<DiscreteResource> other) { return other.stream().filter(x -> map.containsKey(getClass(x))) .anyMatch(x -> map.get(getClass(x)).contains(x)); } @Override public DiscreteResources add(DiscreteResources other) { if (other instanceof EncodableDiscreteResources) { EncodableDiscreteResources cast = (EncodableDiscreteResources) other; LinkedHashMap<Class<?>, EncodedDiscreteResources> newMap = Stream .concat(this.map.entrySet().stream(), cast.map.entrySet().stream()) .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue, EncodedDiscreteResources::add, LinkedHashMap::new)); return of(parent, newMap); } else if (other instanceof EmptyDiscreteResources) { return this; } return DiscreteResources.of(Sets.union(this.values(), other.values())); } @Override public Set<DiscreteResource> values() { return map.values().stream().flatMap(x -> x.values(parent.id()).stream()) .collect(Collectors.toCollection(LinkedHashSet::new)); } @Override public <T> Set<DiscreteResource> valuesOf(Class<T> cls) { return Optional.ofNullable(map.get(cls)).map(x -> x.values(parent.id())).orElse(ImmutableSet.of()); } DiscreteResource parent() { return parent; } Map<Class<?>, EncodedDiscreteResources> rawValues() { return map; } @Override public int hashCode() { return Objects.hash(parent, map); } @Override public boolean equals(Object obj) { if (this == obj) { return true; } if (obj == null || getClass() != obj.getClass()) { return false; } final EncodableDiscreteResources other = (EncodableDiscreteResources) obj; return Objects.equals(this.parent, other.parent) && Objects.equals(this.map, other.map); } @Override public String toString() { return MoreObjects.toStringHelper(this).add("values", values()).toString(); } }