+++ /dev/null
-/*******************************************************************************\r
- * ============LICENSE_START==================================================\r
- * * org.onap.dmaap\r
- * * ===========================================================================\r
- * * Copyright © 2017 AT&T Intellectual Property. All rights reserved.\r
- * * ===========================================================================\r
- * * Licensed under the Apache License, Version 2.0 (the "License");\r
- * * you may not use this file except in compliance with the License.\r
- * * You may obtain a copy of the License at\r
- * * \r
- * * http://www.apache.org/licenses/LICENSE-2.0\r
- * * \r
- * * Unless required by applicable law or agreed to in writing, software\r
- * * distributed under the License is distributed on an "AS IS" BASIS,\r
- * * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\r
- * * See the License for the specific language governing permissions and\r
- * * limitations under the License.\r
- * * ============LICENSE_END====================================================\r
- * *\r
- * * ECOMP is a trademark and service mark of AT&T Intellectual Property.\r
- * *\r
- ******************************************************************************/\r
-\r
-\r
-package com.att.research.datarouter.node;\r
-\r
-import java.util.*;\r
-\r
-/**\r
- * Execute an operation no more frequently than a specified interval\r
- */\r
-\r
-public abstract class RateLimitedOperation implements Runnable {\r
- private boolean marked; // a timer task exists\r
- private boolean executing; // the operation is currently in progress\r
- private boolean remark; // a request was made while the operation was in progress\r
- private Timer timer;\r
- private long last; // when the last operation started\r
- private long mininterval;\r
- /**\r
- * Create a rate limited operation\r
- * @param mininterval The minimum number of milliseconds after the last execution starts before a new execution can begin\r
- * @param timer The timer used to perform deferred executions\r
- */\r
- public RateLimitedOperation(long mininterval, Timer timer) {\r
- this.timer = timer;\r
- this.mininterval = mininterval;\r
- }\r
- private class deferred extends TimerTask {\r
- public void run() {\r
- execute();\r
- }\r
- }\r
- private synchronized void unmark() {\r
- marked = false;\r
- }\r
- private void execute() {\r
- unmark();\r
- request();\r
- }\r
- /**\r
- * Request that the operation be performed by this thread or at a later time by the timer\r
- */\r
- public void request() {\r
- if (premark()) {\r
- return;\r
- }\r
- do {\r
- run();\r
- } while (demark());\r
- }\r
- private synchronized boolean premark() {\r
- if (executing) {\r
- // currently executing - wait until it finishes\r
- remark = true;\r
- return(true);\r
- }\r
- if (marked) {\r
- // timer currently running - will run when it expires\r
- return(true);\r
- }\r
- long now = System.currentTimeMillis();\r
- if (last + mininterval > now) {\r
- // too soon - schedule a timer\r
- marked = true;\r
- timer.schedule(new deferred(), last + mininterval - now);\r
- return(true);\r
- }\r
- last = now;\r
- executing = true;\r
- // start execution\r
- return(false);\r
- }\r
- private synchronized boolean demark() {\r
- executing = false;\r
- if (remark) {\r
- remark = false;\r
- return(!premark());\r
- }\r
- return(false);\r
- }\r
-}\r