| 1 | /* |
| 2 | * Copyright (c) 2005-2010, WSO2 Inc. (http://www.wso2.org) All Rights Reserved. |
| 3 | * |
| 4 | * WSO2 Inc. licenses this file to you under the Apache License, |
| 5 | * Version 2.0 (the "License"); you may not use this file except |
| 6 | * in compliance with the License. |
| 7 | * You may obtain a copy of the License at |
| 8 | * |
| 9 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 10 | * |
| 11 | * Unless required by applicable law or agreed to in writing, |
| 12 | * software distributed under the License is distributed on an |
| 13 | * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| 14 | * KIND, either express or implied. See the License for the |
| 15 | * specific language governing permissions and limitations |
| 16 | * under the License. |
| 17 | */ |
| 18 | package org.wso2.siddhi.core.stream.handler.window; |
| 19 | |
| 20 | import org.wso2.siddhi.core.event.ComplexEvent; |
| 21 | import org.wso2.siddhi.core.event.Event; |
| 22 | import org.wso2.siddhi.core.event.ListEvent; |
| 23 | import org.wso2.siddhi.core.event.StreamEvent; |
| 24 | import org.wso2.siddhi.core.event.remove.RemoveEvent; |
| 25 | import org.wso2.siddhi.core.event.remove.RemoveListEvent; |
| 26 | import org.wso2.siddhi.core.util.SchedulerQueue; |
| 27 | |
| 28 | public class LengthWindowHandler extends WindowHandler { |
| 29 | |
| 30 | int lengthToKeep; |
| 31 | private volatile int currentLength = 0; |
| 32 | |
| 33 | @Override |
| 34 | public void setParameters(Object[] parameters) { |
| 35 | lengthToKeep = (Integer) parameters[0]; |
| 36 | } |
| 37 | |
| 38 | @Override |
| 39 | public void process(ComplexEvent complexEvent) { |
| 40 | try { |
| 41 | if (complexEvent instanceof Event) { |
| 42 | SchedulerQueue<StreamEvent> queue = getWindow(); |
| 43 | queue.put((StreamEvent) complexEvent); |
| 44 | getNextPreStreamFlowProcessor().process(complexEvent); |
| 45 | if (currentLength == lengthToKeep) { |
| 46 | getNextPreStreamFlowProcessor().process(new RemoveEvent((Event) queue.take(),System.currentTimeMillis())); |
| 47 | }else { |
| 48 | currentLength++; |
| 49 | } |
| 50 | } else if (complexEvent instanceof ListEvent) { |
| 51 | SchedulerQueue<StreamEvent> queue = getWindow(); |
| 52 | Event[] newEvents = ((ListEvent) complexEvent).getEvents(); |
| 53 | int oldEventLength = newEvents.length - (lengthToKeep - currentLength); |
| 54 | if (oldEventLength > 0) { |
| 55 | Event[] oldEvents = new Event[newEvents.length - (lengthToKeep - currentLength)]; |
| 56 | int oldEventIndex = 0; |
| 57 | for (Event event : newEvents) { |
| 58 | queue.put(event); |
| 59 | getNextPreStreamFlowProcessor().process(event); |
| 60 | if (currentLength == lengthToKeep) { |
| 61 | oldEvents[oldEventIndex] = new RemoveEvent((Event) queue.take(),System.currentTimeMillis()); |
| 62 | oldEventIndex++; |
| 63 | } else { |
| 64 | currentLength++; |
| 65 | } |
| 66 | } |
| 67 | getNextPreStreamFlowProcessor().process(new RemoveListEvent(oldEvents,System.currentTimeMillis())); |
| 68 | } else { |
| 69 | for (Event event : newEvents) { |
| 70 | queue.put(event); |
| 71 | getNextPreStreamFlowProcessor().process(event); |
| 72 | currentLength++; |
| 73 | } |
| 74 | } |
| 75 | } |
| 76 | } catch (InterruptedException e) { |
| 77 | e.printStackTrace(); |
| 78 | } |
| 79 | } |
| 80 | |
| 81 | } |