Github user chinmaykolhatkar commented on a diff in the pull request:
https://github.com/apache/apex-malhar/pull/319#discussion_r68474418
--- Diff:
library/src/main/java/org/apache/apex/malhar/lib/window/impl/AbstractWindowedOperator.java
---
@@ -0,0 +1,486 @@
+/**
+ * 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 org.apache.apex.malhar.lib.window.impl;
+
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+
+import javax.validation.ValidationException;
+
+import org.joda.time.Duration;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import org.apache.apex.malhar.lib.window.Accumulation;
+import org.apache.apex.malhar.lib.window.ControlTuple;
+import org.apache.apex.malhar.lib.window.TriggerOption;
+import org.apache.apex.malhar.lib.window.Tuple;
+import org.apache.apex.malhar.lib.window.Window;
+import org.apache.apex.malhar.lib.window.WindowOption;
+import org.apache.apex.malhar.lib.window.WindowState;
+import org.apache.apex.malhar.lib.window.WindowedOperator;
+import org.apache.apex.malhar.lib.window.WindowedStorage;
+import org.apache.hadoop.classification.InterfaceStability;
+
+import com.google.common.base.Function;
+
+import com.datatorrent.api.Context;
+import com.datatorrent.api.DefaultInputPort;
+import com.datatorrent.api.DefaultOutputPort;
+import com.datatorrent.api.annotation.InputPortFieldAnnotation;
+import com.datatorrent.common.util.BaseOperator;
+
+/**
+ * This is the abstract windowed operator class that implements most of
the windowing, triggering, and accumulating
+ * concepts. The subclass of this abstract class is supposed to provide
the implementation of how the accumulated
+ * values are stored in the storage.
+ *
+ */
[email protected]
+public abstract class AbstractWindowedOperator<InputT, OutputT,
DataStorageT extends WindowedStorage, AccumulationT extends Accumulation>
+ extends BaseOperator implements WindowedOperator<InputT>
+{
+
+ protected WindowOption windowOption;
+ protected TriggerOption triggerOption;
+ protected long allowedLatenessMillis = -1;
+ protected WindowedStorage<WindowState> windowStateMap;
+
+ private Function<InputT, Long> timestampExtractor;
+
+ private long currentWatermark;
+ private boolean triggerAtWatermark;
+ private long earlyTriggerCount;
+ private long earlyTriggerMillis;
+ private long lateTriggerCount;
+ private long lateTriggerMillis;
+ private long currentDerivedTimestamp = -1;
+ private long windowWidthMillis;
+ protected DataStorageT dataStorage;
+ protected DataStorageT retractionStorage;
+ protected AccumulationT accumulation;
+
+ private static final transient Logger LOG =
LoggerFactory.getLogger(AbstractWindowedOperator.class);
+
+ public final transient DefaultInputPort<Tuple<InputT>> input = new
DefaultInputPort<Tuple<InputT>>()
+ {
+ @Override
+ public void process(Tuple<InputT> tuple)
+ {
+ processTuple(tuple);
+ }
+ };
+
+ // TODO: This port should be removed when Apex Core has native support
for custom control tuples
+ @InputPortFieldAnnotation(optional = true)
+ public final transient DefaultInputPort<ControlTuple> controlInput = new
DefaultInputPort<ControlTuple>()
+ {
+ @Override
+ public void process(ControlTuple tuple)
+ {
+ if (tuple instanceof ControlTuple.Watermark) {
+ processWatermark((ControlTuple.Watermark)tuple);
+ }
+ }
+ };
+
+
+ // TODO: multiple input ports for join operations
+
+ public final transient DefaultOutputPort<Tuple<OutputT>> output = new
DefaultOutputPort<>();
+
+ // TODO: This port should be removed when Apex Core has native support
for custom control tuples
+ public final transient DefaultOutputPort<ControlTuple> controlOutput =
new DefaultOutputPort<>();
+
+ /**
+ * Process the incoming data tuple
+ *
+ * @param tuple
+ */
+ public void processTuple(Tuple<InputT> tuple)
+ {
+ long timestamp = extractTimestamp(tuple);
+ if (isTooLate(timestamp)) {
+ dropTuple(tuple);
+ } else {
+ Tuple.WindowedTuple<InputT> windowedTuple = getWindowedValue(tuple);
+ // do the accumulation
+ accumulateTuple(windowedTuple);
+
+ for (Window window : windowedTuple.getWindows()) {
+ WindowState windowState = windowStateMap.get(window);
+ windowState.tupleCount++;
+ // process any count based triggers
+ if (windowState.watermarkArrivalTime == -1) {
+ // watermark has not arrived yet, check for early count based
trigger
+ if (earlyTriggerCount > 0 && (windowState.tupleCount %
earlyTriggerCount) == 0) {
+ fireTrigger(window, windowState);
+ }
+ } else {
+ // watermark has arrived, check for late count based trigger
+ if (lateTriggerCount > 0 && (windowState.tupleCount %
lateTriggerCount) == 0) {
+ fireTrigger(window, windowState);
+ }
+ }
+ }
+ }
+ }
+
+ @Override
+ public void setWindowOption(WindowOption windowOption)
+ {
+ this.windowOption = windowOption;
+ if (this.windowOption instanceof WindowOption.GlobalWindow) {
+ windowStateMap.put(Window.GLOBAL_WINDOW, new WindowState());
+ }
+ }
+
+ @Override
+ public void setTriggerOption(TriggerOption triggerOption)
+ {
+ this.triggerOption = triggerOption;
+ for (TriggerOption.Trigger trigger : triggerOption.getTriggerList()) {
+ switch (trigger.getWatermarkOpt()) {
+ case ON_TIME:
+ triggerAtWatermark = true;
+ break;
+ case EARLY:
+ if (trigger instanceof TriggerOption.TimeTrigger) {
+ earlyTriggerMillis =
((TriggerOption.TimeTrigger)trigger).getDuration().getMillis();
+ } else if (trigger instanceof TriggerOption.CountTrigger) {
+ earlyTriggerCount =
((TriggerOption.CountTrigger)trigger).getCount();
+ }
+ break;
+ case LATE:
+ if (trigger instanceof TriggerOption.TimeTrigger) {
+ lateTriggerMillis =
((TriggerOption.TimeTrigger)trigger).getDuration().getMillis();
+ } else if (trigger instanceof TriggerOption.CountTrigger) {
+ lateTriggerCount =
((TriggerOption.CountTrigger)trigger).getCount();
+ }
+ break;
+ default:
+ throw new RuntimeException("Unexpected watermark option: " +
trigger.getWatermarkOpt());
+ }
+ }
+ }
+
+ @Override
+ public void setAllowedLateness(Duration allowedLateness)
+ {
+ this.allowedLatenessMillis = allowedLateness.getMillis();
+ }
+
+ /**
+ * This method sets the storage for the data for each window
+ *
+ * @param storageAgent
+ */
+ public void setDataStorage(DataStorageT storageAgent)
+ {
+ this.dataStorage = storageAgent;
+ }
+
+ /**
+ * This method sets the storage for the retraction data for each window.
Only used when the accumulation mode is ACCUMULATING_AND_RETRACTING
+ *
+ * @param storageAgent
+ */
+ public void setRetractionStorage(DataStorageT storageAgent)
+ {
+ this.retractionStorage = storageAgent;
+ }
+
+ /**
+ * Sets the accumulation, which basically tells the WindowedOperator
what to do if a new tuple comes in and what
+ * to put in the pane when a trigger is fired
+ *
+ * @param accumulation
+ */
+ public void setAccumulation(AccumulationT accumulation)
+ {
+ this.accumulation = accumulation;
+ }
+
+ @Override
+ public void setWindowStateStorage(WindowedStorage<WindowState>
storageAgent)
+ {
+ this.windowStateMap = storageAgent;
+ }
+
+ @Override
+ public void setTimestampExtractor(Function<InputT, Long>
timestampExtractor)
+ {
+ this.timestampExtractor = timestampExtractor;
+ }
+
+ public void validate() throws ValidationException
+ {
+ if (accumulation == null) {
+ throw new ValidationException("Accumulation must be set");
+ }
+ if (dataStorage == null) {
+ throw new ValidationException("Data storage must be set");
+ }
+ if (windowStateMap == null) {
+ throw new ValidationException("Window state storage must be set");
+ }
+ if (triggerOption != null) {
+ if (triggerOption.isFiringOnlyUpdatedPanes()) {
+ if (retractionStorage == null) {
+ throw new ValidationException("A retraction storage is required
for firingOnlyUpdatedPanes option");
+ }
+ if (triggerOption.getAccumulationMode() ==
TriggerOption.AccumulationMode.DISCARDING) {
+ throw new ValidationException("DISCARDING accumulation mode is
not valid for firingOnlyUpdatedPanes option");
+ }
+ }
+ if (triggerOption.getAccumulationMode() ==
TriggerOption.AccumulationMode.ACCUMULATING_AND_RETRACTING &&
+ retractionStorage == null) {
+ throw new ValidationException("A retraction storage is required
for ACCUMULATING_AND_RETRACTING accumulation mode");
+ }
+ }
+ }
+
+ @Override
+ public Tuple.WindowedTuple<InputT> getWindowedValue(Tuple<InputT> input)
+ {
+ Tuple.WindowedTuple<InputT> windowedTuple = new
Tuple.WindowedTuple<>();
+ windowedTuple.setValue(input.getValue());
+ windowedTuple.setTimestamp(extractTimestamp(input));
+ assignWindows(windowedTuple.getWindows(), input);
+ return windowedTuple;
+ }
+
+ private long extractTimestamp(Tuple<InputT> tuple)
+ {
+ if (timestampExtractor == null) {
+ if (tuple instanceof Tuple.TimestampedTuple) {
+ return ((Tuple.TimestampedTuple)tuple).getTimestamp();
+ } else {
+ return 0;
+ }
+ } else {
+ return timestampExtractor.apply(tuple.getValue());
+ }
+ }
+
+ private void assignWindows(List<Window> windows, Tuple<InputT>
inputTuple)
+ {
--- End diff --
Minor nit: Considering WindowedTuple has a addWindow method, maybe it just
make sense to have only single parameter to this method "WindowedTuple<InputT>
tuple".. Rest all can be derived from this object.
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at [email protected] or file a JIRA ticket
with INFRA.
---
