| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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.apache.brooklyn.api.sensor; |
| |
| import org.apache.brooklyn.api.mgmt.rebind.RebindSupport; |
| import org.apache.brooklyn.api.mgmt.rebind.Rebindable; |
| import org.apache.brooklyn.api.mgmt.rebind.mementos.FeedMemento; |
| import org.apache.brooklyn.api.objs.EntityAdjunct; |
| |
| import com.google.common.annotations.Beta; |
| |
| /** |
| * A sensor feed. |
| * These generally poll or subscribe to get sensor values for an entity. |
| * They make it easy to poll over http, jmx, etc. |
| * |
| * Assumes: |
| * <ul> |
| * <li>There will not be concurrent calls to start and stop. |
| * <li>There will only be one call to start and that will be done immediately after construction, |
| * in the same thread. |
| * <li>Once stopped, the feed will not be re-started. |
| * </ul> |
| */ |
| @Beta |
| public interface Feed extends EntityAdjunct, Rebindable { |
| |
| /** |
| * True if everything has been _started_ (or it is starting) but not stopped, |
| * even if it is suspended; see also {@link #isRunning()} |
| */ |
| boolean isActivated(); |
| |
| void start(); |
| |
| /** suspends this feed (stops the poller, or indicates that the feed should start in a state where the poller is stopped) */ |
| void suspend(); |
| |
| boolean isSuspended(); |
| |
| /** resumes this feed if it has been suspended and not stopped */ |
| void resume(); |
| |
| void stop(); |
| |
| /** |
| * Users are strongly discouraged from calling or overriding this method. |
| * It is for internal calls only, relating to persisting/rebinding entities. |
| * This method may change (or be removed) in a future release without notice. |
| */ |
| @Override |
| @Beta |
| RebindSupport<FeedMemento> getRebindSupport(); |
| |
| @Override |
| RelationSupport<Feed> relations(); |
| |
| } |