| /* |
| * Copyright 2015-2016 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.net.newresource; |
| |
| import com.google.common.annotations.Beta; |
| import com.google.common.base.MoreObjects; |
| import org.onosproject.net.DeviceId; |
| import org.onosproject.net.PortNumber; |
| |
| import java.util.List; |
| import java.util.Objects; |
| import java.util.Optional; |
| |
| import static com.google.common.base.Preconditions.checkArgument; |
| import static com.google.common.base.Preconditions.checkNotNull; |
| import static com.google.common.base.Preconditions.checkState; |
| |
| /** |
| * An object that represent a resource in a network. |
| * A Resource can represents path-like hierarchical structure with its ID. An ID of resource is |
| * composed of a sequence of elementary resources that are not globally identifiable. A Resource |
| * can be globally identifiable by its ID. |
| * |
| * Two types of resource are considered. One is discrete type and the other is continuous type. |
| * Discrete type resource is a resource whose amount is measured as a discrete unit. VLAN ID and |
| * MPLS label are examples of discrete type resource. Continuous type resource is a resource whose |
| * amount is measured as a continuous value. Bandwidth is an example of continuous type resource. |
| * A double value is associated with a continuous type value. |
| * |
| * Users of this class must keep the semantics of resources regarding the hierarchical structure. |
| * For example, resource, Device:1/Port:1/VLAN ID:100, is valid, but resource, |
| * VLAN ID:100/Device:1/Port:1 is not valid because a link is not a sub-component of a VLAN ID. |
| */ |
| @Beta |
| public abstract class Resource { |
| |
| private final Discrete parent; |
| private final ResourceId id; |
| |
| public static final Discrete ROOT = new Discrete(); |
| |
| public static Resource discrete(DeviceId device) { |
| return new Discrete(ResourceId.discrete(device)); |
| } |
| |
| /** |
| * Creates an resource path which represents a discrete-type resource from the specified components. |
| * |
| * @param device device ID which is the first component of the path |
| * @param components following components of the path. The order represents hierarchical structure of the resource. |
| * @return resource path instance |
| */ |
| public static Resource discrete(DeviceId device, Object... components) { |
| return new Discrete(ResourceId.discrete(device, components)); |
| } |
| |
| /** |
| * Creates an resource path which represents a discrete-type resource from the specified components. |
| * |
| * @param device device ID which is the first component of the path |
| * @param port port number which is the second component of the path |
| * @param components following components of the path. The order represents hierarchical structure of the resource. |
| * @return resource path instance |
| */ |
| public static Resource discrete(DeviceId device, PortNumber port, Object... components) { |
| return new Discrete(ResourceId.discrete(device, port, components)); |
| } |
| |
| /** |
| * Creates an resource path which represents a continuous-type resource from the specified components. |
| * |
| * @param value amount of the resource |
| * @param device device ID which is the first component of the path |
| * @param components following components of the path. The order represents hierarchical structure of the resource. |
| * The last element of this list must be an {@link Class} instance. Otherwise, this method throws |
| * an IllegalArgumentException. |
| * @return resource path instance |
| */ |
| public static Resource continuous(double value, DeviceId device, Object... components) { |
| checkArgument(components.length > 0, |
| "Length of components must be greater thant 0, but " + components.length); |
| |
| return new Continuous(ResourceId.continuous(device, components), value); |
| } |
| |
| /** |
| * Creates an resource path which represents a continuous-type resource from the specified components. |
| * |
| * @param value amount of the resource |
| * @param device device ID which is the first component of the path. |
| * @param port port number which is the second component of the path. |
| * @param components following components of the path. The order represents hierarchical structure of the resource. |
| * The last element of this list must be an {@link Class} instance. Otherwise, this method throws |
| * an IllegalArgumentException. |
| * @return resource path instance |
| */ |
| public static Resource continuous(double value, DeviceId device, PortNumber port, Object... components) { |
| return new Continuous(ResourceId.continuous(device, port, components), value); |
| } |
| |
| /** |
| * Creates an resource path from the specified id. |
| * |
| * @param id id of the path |
| */ |
| protected Resource(ResourceId id) { |
| checkNotNull(id); |
| |
| this.id = id; |
| if (id.components.size() == 1) { |
| this.parent = ROOT; |
| } else { |
| this.parent = new Discrete(id.parent()); |
| } |
| } |
| |
| // for serialization |
| private Resource() { |
| this.parent = null; |
| this.id = ResourceId.ROOT; |
| } |
| |
| /** |
| * Returns the components of this resource path. |
| * |
| * @return the components of this resource path |
| */ |
| public List<Object> components() { |
| return id.components; |
| } |
| |
| /** |
| * Returns the volume of this resource. |
| * |
| * @return the volume of this resource |
| */ |
| // TODO: think about other naming possibilities. amount? quantity? |
| public abstract <T> T volume(); |
| |
| /** |
| * Returns the parent resource path of this instance. |
| * E.g. if this path is Link:1/VLAN ID:100, the return value is the resource path for Link:1. |
| * |
| * @return the parent resource path of this instance. |
| * If there is no parent, empty instance will be returned. |
| */ |
| public Optional<Discrete> parent() { |
| return Optional.ofNullable(parent); |
| } |
| |
| /** |
| * Returns a child resource path of this instance with specifying the child object. |
| * The child resource path is discrete-type. |
| * |
| * @param child child object |
| * @return a child resource path |
| */ |
| public Resource child(Object child) { |
| checkState(this instanceof Discrete); |
| |
| return new Discrete(id().child(child)); |
| } |
| |
| /** |
| * Returns a child resource path of this instance with specifying a child object and |
| * value. The child resource path is continuous-type. |
| * |
| * @param child child object |
| * @param value value |
| * @return a child resource path |
| */ |
| public Resource child(Object child, double value) { |
| checkState(this instanceof Discrete); |
| |
| return new Continuous(id.child(child), value); |
| } |
| |
| /** |
| * Returns the last component of this instance. |
| * |
| * @return the last component of this instance. |
| * The return value is equal to the last object of {@code components()}. |
| */ |
| public Object last() { |
| if (id.components.isEmpty()) { |
| return null; |
| } |
| return id.components.get(id.components.size() - 1); |
| } |
| |
| /** |
| * Returns the ID of this resource path. |
| * |
| * @return the ID of this resource path |
| */ |
| public ResourceId id() { |
| return id; |
| } |
| |
| @Override |
| public String toString() { |
| return MoreObjects.toStringHelper(this) |
| .add("id", id()) |
| .add("volume", volume()) |
| .toString(); |
| } |
| |
| /** |
| * Represents a resource path which specifies a resource which can be measured |
| * as a discrete unit. A VLAN ID and a MPLS label of a link are examples of the resource. |
| * <p> |
| * Note: This class is exposed to the public, but intended to be used in the resource API |
| * implementation only. It is not for resource API user. |
| * </p> |
| */ |
| @Beta |
| public static final class Discrete extends Resource { |
| private Discrete() { |
| super(); |
| } |
| |
| private Discrete(ResourceId id) { |
| super(id); |
| } |
| |
| /** |
| * The user of this methods must receive the return value as the correct type. |
| * Otherwise, this methods throws an exception. |
| * |
| * @param <T> type of the return value |
| * @return the volume of this resource |
| */ |
| @SuppressWarnings("unchecked") |
| @Override |
| // TODO: consider receiving Class<T> as an argument. Which approach is convenient? |
| public <T> T volume() { |
| return (T) last(); |
| } |
| |
| @Override |
| public int hashCode() { |
| // the value returing from volume() is excluded due to optimization |
| return id().hashCode(); |
| } |
| |
| @Override |
| public boolean equals(Object obj) { |
| if (this == obj) { |
| return true; |
| } |
| if (obj == null || getClass() != obj.getClass()) { |
| return false; |
| } |
| final Discrete other = (Discrete) obj; |
| // the value returing from volume() is excluded due to optimization |
| return Objects.equals(this.id(), other.id()); |
| } |
| } |
| |
| /** |
| * Represents a resource path which specifies a resource which can be measured |
| * as continuous value. Bandwidth of a link is an example of the resource. |
| * <p> |
| * Note: This class is exposed to the public, but intended to be used in the resource API |
| * implementation only. It is not for resource API user. |
| */ |
| @Beta |
| public static final class Continuous extends Resource { |
| private final double value; |
| |
| private Continuous(ResourceId id, double value) { |
| super(id); |
| this.value = value; |
| } |
| |
| /** |
| * The user of this methods must receive the return value as Double or double. |
| * Otherwise, this methods throws an exception. |
| * |
| * @param <T> type of the return value |
| * @return the volume of this resource |
| */ |
| @SuppressWarnings("unchecked") |
| @Override |
| public <T> T volume() { |
| return (T) Double.valueOf(value); |
| } |
| |
| @Override |
| public int hashCode() { |
| return Objects.hash(id(), value); |
| } |
| |
| @Override |
| public boolean equals(Object obj) { |
| if (this == obj) { |
| return true; |
| } |
| if (obj == null || getClass() != obj.getClass()) { |
| return false; |
| } |
| final Continuous other = (Continuous) obj; |
| return Objects.equals(this.id(), other.id()) |
| && Objects.equals(this.value, other.value); |
| } |
| |
| /** |
| * Returns the value of the resource amount. |
| * |
| * @return the value of the resource amount |
| */ |
| // FIXME: overlapping a purpose with volume() |
| public double value() { |
| return value; |
| } |
| } |
| |
| } |