| /* |
| * Copyright 2015 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.consistent.impl; |
| |
| import static com.google.common.base.MoreObjects.toStringHelper; |
| |
| import java.util.Objects; |
| |
| /** |
| * Result of a database update operation. |
| * |
| * @param <V> return value type |
| */ |
| public final class Result<V> { |
| |
| public enum Status { |
| /** |
| * Indicates a successful update. |
| */ |
| OK, |
| |
| /** |
| * Indicates a failure due to underlying state being locked by another transaction. |
| */ |
| LOCKED |
| } |
| |
| private final Status status; |
| private final V value; |
| |
| /** |
| * Creates a new Result instance with the specified value with status set to Status.OK. |
| * |
| * @param <V> result value type |
| * @param value result value |
| * @return Result instance |
| */ |
| public static <V> Result<V> ok(V value) { |
| return new Result<>(value, Status.OK); |
| } |
| |
| /** |
| * Creates a new Result instance with status set to Status.LOCKED. |
| * |
| * @param <V> result value type |
| * @return Result instance |
| */ |
| public static <V> Result<V> locked() { |
| return new Result<>(null, Status.LOCKED); |
| } |
| |
| private Result(V value, Status status) { |
| this.value = value; |
| this.status = status; |
| } |
| |
| /** |
| * Returns true if this result indicates a successful execution i.e status is Status.OK. |
| * |
| * @return true if successful, false otherwise |
| */ |
| public boolean success() { |
| return status == Status.OK; |
| } |
| |
| /** |
| * Returns the status of database update operation. |
| * |
| * @return database update status |
| */ |
| public Status status() { |
| return status; |
| } |
| |
| /** |
| * Returns the return value for the update. |
| * |
| * @return value returned by database update. If the status is another |
| * other than Status.OK, this returns a null |
| */ |
| public V value() { |
| return value; |
| } |
| |
| @Override |
| public int hashCode() { |
| return Objects.hash(value, status); |
| } |
| |
| @SuppressWarnings("unchecked") |
| @Override |
| public boolean equals(Object other) { |
| if (!(other instanceof Result)) { |
| return false; |
| } |
| Result<V> that = (Result<V>) other; |
| return Objects.equals(this.value, that.value) && |
| Objects.equals(this.status, that.status); |
| } |
| |
| @Override |
| public String toString() { |
| return toStringHelper(this) |
| .add("status", status) |
| .add("value", value) |
| .toString(); |
| } |
| } |