Github user chaithu14 commented on a diff in the pull request:
https://github.com/apache/incubator-apex-malhar/pull/113#discussion_r46119349
--- Diff:
library/src/main/java/com/datatorrent/lib/join/AbstractJoinOperator.java ---
@@ -0,0 +1,343 @@
+/**
+ * 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 com.datatorrent.lib.join;
+
+import java.lang.reflect.Array;
+import java.util.ArrayList;
+import java.util.Calendar;
+import java.util.List;
+
+import org.apache.hadoop.classification.InterfaceStability.Evolving;
+
+import com.datatorrent.api.Context;
+import com.datatorrent.api.DefaultInputPort;
+import com.datatorrent.api.DefaultOutputPort;
+import com.datatorrent.api.Operator;
+import com.datatorrent.api.annotation.InputPortFieldAnnotation;
+import com.datatorrent.common.util.BaseOperator;
+
+/**
+ * <p>
+ * This is the base implementation of join operator. Operator receives
tuples from multiple streams,
+ * applies the join operation based on constraint and emit the joined
value.
+ * Subclasses should provide implementation to
createOutputTuple,copyValue, getKeyValue, getTime methods.
+ *
+ * <b>Properties:</b><br>
+ * <b>expiryTime</b>: Expiry time for stored tuples<br>
+ * <b>includeFieldStr</b>: List of comma separated fields to be added to
the output tuple.
+ * Ex: Field1,Field2;Field3,Field4<br>
+ * <b>keyFields</b>: List of comma separated key field for both the
streams. Ex: Field1,Field2<br>
+ * <b>timeFields</b>: List of comma separated time field for both the
streams. Ex: Field1,Field2<br>
+ * <b>bucketSpanInMillis</b>: Span of each bucket in milliseconds.<br>
+ * <b>strategy</b>: Type of join operation. Default type is inner join<br>
+ * <br>
+ * </p>
+ *
+ * @displayName Abstract Join Operator
+ * @tags join
+ */
+@Evolving
+public abstract class AbstractJoinOperator<T> extends BaseOperator
implements Operator.CheckpointListener
+{
+ public final transient DefaultOutputPort<List<T>> outputPort = new
DefaultOutputPort<>();
+ protected String[] timeFields;
+
+ protected String[][] includeFields;
+ // Fields to compare from both the streams
+ protected String[] keys;
+ // Strategy of Join operation, by default the option is inner join
+ protected JoinStrategy strategy = JoinStrategy.INNER_JOIN;
+ // This represents whether the processing tuple is from left port or not
+ protected Boolean isLeft;
+ @InputPortFieldAnnotation(optional = true)
+ public transient DefaultInputPort<T> input1 = new DefaultInputPort<T>()
+ {
+ @Override
+ public void process(T tuple)
+ {
+ isLeft = true;
+ processTuple(tuple);
+ }
+ };
+ @InputPortFieldAnnotation(optional = true)
+ public transient DefaultInputPort<T> input2 = new DefaultInputPort<T>()
+ {
+ @Override
+ public void process(T tuple)
+ {
+ isLeft = false;
+ processTuple(tuple);
+ }
+ };
+ // Stores for each of the input port
+ private BackupStore[] store =
(BackupStore[])Array.newInstance(BackupStore.class, 2);
+ private String includeFieldStr;
+ private String keyFieldStr;
+ private String timeFieldStr;
+
+ @Override
+ public void setup(Context.OperatorContext context)
+ {
+ if (store[0] == null) {
+ throw new RuntimeException("Left Store is Empty");
+ }
+ if (store[1] == null) {
+ throw new RuntimeException("Right Store is Empty");
+ }
+ // Checks whether the strategy is outer join and set it to store
+ boolean isOuter = strategy.equals(JoinStrategy.LEFT_OUTER_JOIN) ||
strategy.equals(JoinStrategy.OUTER_JOIN);
+ store[0].isOuterJoin(isOuter);
+ isOuter = strategy.equals(JoinStrategy.RIGHT_OUTER_JOIN) ||
strategy.equals(JoinStrategy.OUTER_JOIN);
+ store[1].isOuterJoin(isOuter);
+ // Setup the stores
+ store[0].setup();
+ store[1].setup();
+
+ populateFields();
+ }
+
+ /**
+ * Create the event with the given tuple. If it successfully inserted it
into the store
+ * then it does the join operation
+ *
+ * @param tuple Tuple to process
+ */
+ protected void processTuple(T tuple)
+ {
+ int idx = 0;
+ if (!isLeft) {
+ idx = 1;
+ }
+ TimeEvent t = createEvent(tuple);
+ if (store[idx].put(t)) {
+ join(t, isLeft);
+ }
+ }
+
+ private void populateFields()
+ {
+ populateIncludeFields();
+ populateKeyFields();
+ if (timeFieldStr != null) {
+ populateTimeFields();
+ }
+ }
+
+ /**
+ * Populate the fields from the includeFiledStr
+ */
+ private void populateIncludeFields()
+ {
+ includeFields = new String[2][];
+ String[] portFields = includeFieldStr.split(";");
+ for (int i = 0; i < portFields.length; i++) {
+ includeFields[i] = portFields[i].split(",");
+ }
+ }
+
+ /**
+ * Get the tuples from another store based on join constraint and key
+ *
+ * @param tuple input
+ * @param isLeft whether the given tuple is from first port or not
+ */
+ private void join(TimeEvent tuple, Boolean isLeft)
+ {
+ // Get the valid tuples from the store based on key
+ // If the tuple is null means the join type is outer and return
unmatched tuples from store.
+ Object value;
+ if (isLeft) {
+ if (tuple != null) {
+ value = store[1].getValidTuples(tuple);
+ } else {
+ value = store[1].getUnMatchedTuples();
+ }
+ } else {
+ if (tuple != null) {
+ value = store[0].getValidTuples(tuple);
+ } else {
+ value = store[0].getUnMatchedTuples();
+ }
+ }
+ // Join the input tuple with the joined tuples
+ if (value != null) {
+ ArrayList<TimeEvent> joinedValues = (ArrayList<TimeEvent>)value;
+ List<T> result = new ArrayList<>();
+ for (TimeEvent joinedValue : joinedValues) {
+ T output = createOutputTuple();
+ Object tupleValue = null;
+ if (tuple != null) {
+ tupleValue = tuple.getValue();
+ }
+ copyValue(output, tupleValue, isLeft);
+ copyValue(output, joinedValue.getValue(), !isLeft);
+ result.add(output);
+ joinedValue.setMatch(true);
+ }
+ if (tuple != null) {
+ tuple.setMatch(true);
+ }
+ if (result.size() != 0) {
+ outputPort.emit(result);
+ }
+ }
+ }
+
+ // Emit the unmatched tuples, if the strategy is outer join
+ @Override
+ public void endWindow()
+ {
+ if (strategy.equals(JoinStrategy.LEFT_OUTER_JOIN) ||
strategy.equals(JoinStrategy.OUTER_JOIN)) {
+ join(null, false);
+ }
+ if (strategy.equals(JoinStrategy.RIGHT_OUTER_JOIN) ||
strategy.equals(JoinStrategy.OUTER_JOIN)) {
+ join(null, true);
+ }
+ store[0].endWindow();
+ store[1].endWindow();
+ }
+
+ @Override
+ public void checkpointed(long windowId)
+ {
+ store[0].checkpointed(windowId);
+ store[1].checkpointed(windowId);
+ }
+
+ @Override
+ public void committed(long windowId)
+ {
+ store[0].committed(windowId);
+ store[1].committed(windowId);
+ }
+
+ /**
+ * Convert the given tuple to event
+ *
+ * @param tuple Given tuple to convert into event
+ * @return event
+ */
+ protected TimeEvent createEvent(Object tuple)
+ {
+ int idx = 0;
+ if (!isLeft) {
+ idx = 1;
+ }
+ if (timeFields != null) {
+ return new TimeEventImpl(getKeyValue(keys[idx], tuple),
(Long)getTime(timeFields[idx], tuple), tuple);
+ } else {
+ return new TimeEventImpl(getKeyValue(keys[idx], tuple),
Calendar.getInstance().getTimeInMillis(), tuple);
+ }
+ }
+
+ public void populateKeyFields()
+ {
+ this.keys = keyFieldStr.split(",");
+ }
+
+ public JoinStrategy getStrategy()
+ {
+ return strategy;
+ }
+
+ public void setStrategy(JoinStrategy strategy)
+ {
+ this.strategy = strategy;
+ }
+
+ public void setLeftStore(BackupStore lStore)
+ {
+ store[0] = lStore;
+ }
+
+ public void setRightStore(BackupStore rStore)
+ {
+ store[1] = rStore;
+ }
+
+ public void setKeyFields(String keyFieldStr)
+ {
+ this.keyFieldStr = keyFieldStr;
--- End diff --
Made these key, includeFields, timeFields arrays as transient. So, I am
not incorporating this review comment.
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