| /* |
| * Copyright (c) 2013 DataTorrent, Inc. ALL Rights Reserved. |
| * |
| * 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 com.datatorrent.lib.algo; |
| |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| import com.datatorrent.api.DefaultInputPort; |
| import com.datatorrent.api.DefaultOutputPort; |
| import com.datatorrent.api.annotation.OperatorAnnotation; |
| |
| import com.datatorrent.lib.util.BaseMatchOperator; |
| |
| /** |
| * This operator filters the incoming stream of key value pairs by obtaining the values corresponding to a specified key, |
| * and comparing those values to a specified number. The last key value pair, in each window, to satisfy the comparison is emitted. |
| * <p> |
| * A compare function is operated on a tuple value of type String based on the property "key", "value", and "cmp". Every tuple |
| * is checked and the last one that passes the condition is send during end of window on port "last". The comparison is done by getting double |
| * value from the Number. |
| * <p> |
| * This module is an end of window module<br> |
| * <br> |
| * <b>StateFull : Yes, </b> tuple are compare across application window(s). <br> |
| * <b>Partitions : No, </b> will yield wrong result. <br> |
| * <br> |
| * <br> |
| * <b>Ports</b>:<br> |
| * <b>data</b>: expects Map<K,String><br> |
| * <b>last</b>: emits HashMap<K,String> in end of window for the last tuple on which the compare function is true<br> |
| * <br> |
| * <b>Properties</b>:<br> |
| * <b>key</b>: The key on which compare is done<br> |
| * <b>value</b>: The value to compare with<br> |
| * <b>cmp</b>: The compare function. Supported values are "lte", "lt", "eq", "neq", "gt", "gte". Default is "eq"<br> |
| * <br> |
| * <b>Specific compile time checks</b>:<br> |
| * Key must be non empty<br> |
| * Value must be able to convert to a "double"<br> |
| * Compare string, if specified, must be one of "lte", "lt", "eq", "neq", "gt", "gte"<br> |
| * <br> |
| * </p> |
| * |
| * @displayName Emit Last Match (Number) |
| * @category Algorithmic |
| * @tags filter, key value, string |
| * |
| * @since 0.3.2 |
| */ |
| @OperatorAnnotation(partitionable = false) |
| public class LastMatchStringMap<K> extends BaseMatchOperator<K, String> |
| { |
| /** |
| * Last tuple map. |
| */ |
| protected HashMap<K, String> ltuple = null; |
| |
| /** |
| * The input port on which key value pairs are received. |
| */ |
| public final transient DefaultInputPort<Map<K, String>> data = new DefaultInputPort<Map<K, String>>() |
| { |
| /** |
| * Processes tuples and keeps a copy of last matched tuple |
| */ |
| @Override |
| public void process(Map<K, String> tuple) |
| { |
| String val = tuple.get(getKey()); |
| if (val == null) { |
| return; |
| } |
| double tvalue = 0; |
| boolean errortuple = false; |
| try { |
| tvalue = Double.parseDouble(val); |
| } |
| catch (NumberFormatException e) { |
| errortuple = true; |
| } |
| if (!errortuple) { |
| if (compareValue(tvalue)) { |
| ltuple = cloneTuple(tuple); |
| } |
| } |
| } |
| }; |
| |
| /** |
| * The output port on which the last key value pair to satisfy the comparison function is emitted. |
| */ |
| public final transient DefaultOutputPort<HashMap<K, String>> last = new DefaultOutputPort<HashMap<K, String>>(); |
| |
| /** |
| * Emits last matching tuple |
| */ |
| @Override |
| public void endWindow() |
| { |
| if (ltuple != null) { |
| last.emit(ltuple); |
| } |
| ltuple = null; |
| } |
| } |