Github user chandnisingh commented on a diff in the pull request:
https://github.com/apache/incubator-apex-malhar/pull/51#discussion_r44822769
--- Diff:
library/src/main/java/com/datatorrent/lib/streamquery/AntiJoinOperator.java ---
@@ -0,0 +1,205 @@
+/**
+ * Copyright (C) 2015 DataTorrent, Inc.
+ *
+ * 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.streamquery;
+
+import com.datatorrent.api.Context.OperatorContext;
+import com.datatorrent.api.DefaultInputPort;
+import com.datatorrent.api.DefaultOutputPort;
+import com.datatorrent.api.Operator;
+import com.datatorrent.api.annotation.OperatorAnnotation;
+import com.datatorrent.lib.streamquery.condition.Condition;
+import com.datatorrent.lib.streamquery.index.Index;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.Map;
+
+import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.classification.InterfaceStability.Evolving;
+
+/**
+ * An implementation of Operator that reads table row data from two table
data input ports. <br>
+ * <p>
+ * Operator anti-joins row on given condition and selected names, emits
+ * anti-joined result at output port.
+ * <br>
+ * <b>StateFull : Yes,</b> Operator aggregates input over application
window. <br>
+ * <b>Partitions : No, </b> will yield wrong result(s). <br>
+ * <br>
+ * <b>Ports : </b> <br>
+ * <b> inport1 : </b> Input port for table 1, expects HashMap<String,
Object> <br>
+ * <b> inport2 : </b> Input port for table 2, expects HashMap<String,
Object> <br>
+ * <b> outport : </b> Output anti-joined row port, emits
HashMap<String, ArrayList<Object>> <br>
+ * <br>
+ * <b> Properties : </b>
+ * <b> joinCondition : </b> Join condition for table rows. <br>
+ * <b> table1Columns : </b> Columns to be selected from table1. <br>
+ * <b> table2Columns : </b> Columns to be selected from table2. <br>
+ * <br>
+ *
+ * @displayName Anti join
+ * @category Stream Manipulators
+ * @tags sql, anti join operator
+ * @since 0.3.3
+ */
+@OperatorAnnotation(partitionable = false)
+@Evolving
+public class AntiJoinOperator implements Operator
+{
+
+ /**
+ * Join Condition;
+ */
+ protected Condition joinCondition;
+
+ /**
+ * Table1 select columns.
+ * Note: only left table (Table1) will be output in an Anti-join
+ */
+ private ArrayList<Index> table1Columns = new ArrayList<Index>();
+
+ /**
+ * Collect data rows from input port 1.
+ */
+ protected ArrayList<Map<String, Object>> table1;
+
+ /**
+ * Collect data from input port 2.
+ */
+ protected ArrayList<Map<String, Object>> table2;
+
+ /**
+ * Input port 1 that takes a map of <string,object>.
+ */
+ public final transient DefaultInputPort<Map<String, Object>>
+ inport1 = new DefaultInputPort<Map<String, Object>>()
+ {
+ @Override
+ public void process(Map<String, Object> tuple)
+ {
+ table1.add(tuple);
+ for (int j = 0; j < table2.size(); j++) {
+ if ((joinCondition != null)
+ && (joinCondition.isValidJoin(tuple, table2.get(j)))) {
+ table1.remove(tuple);
+ }
+ }
+ }
+ };
+
+ /**
+ * Input port 2 that takes a map of <string,object>.
+ */
+ public final transient DefaultInputPort<Map<String, Object>> inport2
+ = new DefaultInputPort<Map<String, Object>>()
+ {
+ @Override
+ public void process(Map<String, Object> tuple)
+ {
+ table2.add(tuple);
+
+ for (int j = 0; j < table1.size(); j++) {
+ if ((joinCondition != null)
+ && (joinCondition.isValidJoin(table1.get(j), tuple))) {
+ table1.remove(table1.get(j));
+ }
+ }
+ }
+ };
+
+ /**
+ * Output port that emits a map of <string,object>.
+ */
+ public final transient DefaultOutputPort<Map<String, Object>> outport =
+ new DefaultOutputPort<Map<String, Object>>();
+
+ @Override
+ public void setup(OperatorContext arg0)
+ {
+ table1 = new ArrayList<Map<String, Object>>();
+ table2 = new ArrayList<Map<String, Object>>();
+ }
+
+ @Override
+ public void teardown()
+ {
+ }
+
+ @Override
+ public void beginWindow(long arg0)
+ {
+ }
+
+ @Override
+ public void endWindow()
+ {
+ /* All joined rows have been removed
+ * The ones left are the anti-joined result
+ */
+ for (int i = 0; i < table1.size(); i++) {
+ joinRows(table1.get(i));
+ }
+
+ table1.clear();
+ table2.clear();
+ }
+
+ /**
+ * @return the joinCondition
+ */
+ public Condition getJoinCondition()
+ {
+ return joinCondition;
+ }
+
+ /**
+ * Pick the supported condition. Currently only equal join is supported.
+ *
+ * @param set joinCondition
+ */
+ public void setJoinCondition(Condition joinCondition)
+ {
+ this.joinCondition = joinCondition;
+ }
+
+ /**
+ * Select table1 column name.
+ */
+ public void selectTable1Column(Index column)
+ {
+ table1Columns.add(column);
+ }
+
+ /**
+ * Join row from table1 and table2.
+ */
+ protected void joinRows(Map<String, Object> row)
+ {
+ // joined row
+ Map<String, Object> join = new HashMap<String, Object>();
+
+ // filter table1 columns
+ if (row != null) {
+ for (Index index : table1Columns) {
+ index.filter(row, join);
+ }
+ }
+
+ // emit row
+ outport.emit(join);
+ }
+
+}
--- End diff --
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