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* 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.beam.sdk.transforms;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;
import com.google.common.collect.Iterables;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Iterator;
import org.apache.beam.sdk.coders.IterableCoder;
import org.apache.beam.sdk.coders.KvCoder;
import org.apache.beam.sdk.coders.StringUtf8Coder;
import org.apache.beam.sdk.testing.NeedsRunner;
import org.apache.beam.sdk.testing.PAssert;
import org.apache.beam.sdk.testing.TestPipeline;
import org.apache.beam.sdk.testing.TestStream;
import org.apache.beam.sdk.testing.UsesStatefulParDo;
import org.apache.beam.sdk.testing.UsesTestStream;
import org.apache.beam.sdk.testing.UsesTimersInParDo;
import org.apache.beam.sdk.transforms.windowing.BoundedWindow;
import org.apache.beam.sdk.transforms.windowing.FixedWindows;
import org.apache.beam.sdk.transforms.windowing.Window;
import org.apache.beam.sdk.values.KV;
import org.apache.beam.sdk.values.PCollection;
import org.apache.beam.sdk.values.TimestampedValue;
import org.joda.time.Duration;
import org.joda.time.Instant;
import org.junit.Rule;
import org.junit.Test;
import org.junit.experimental.categories.Category;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/** Test Class for {@link GroupIntoBatches}. */
@RunWith(JUnit4.class)
public class GroupIntoBatchesTest implements Serializable {
private static final int BATCH_SIZE = 5;
private static final long NUM_ELEMENTS = 10;
private static final int ALLOWED_LATENESS = 0;
private static final Logger LOGGER = LoggerFactory.getLogger(GroupIntoBatchesTest.class);
@Rule public transient TestPipeline pipeline = TestPipeline.create();
private transient ArrayList<KV<String, String>> data = createTestData();
private static ArrayList<KV<String, String>> createTestData() {
String[] scientists = {
"Einstein",
"Darwin",
"Copernicus",
"Pasteur",
"Curie",
"Faraday",
"Newton",
"Bohr",
"Galilei",
"Maxwell"
};
ArrayList<KV<String, String>> data = new ArrayList<>();
for (int i = 0; i < NUM_ELEMENTS; i++) {
int index = i % scientists.length;
KV<String, String> element = KV.of("key", scientists[index]);
data.add(element);
}
return data;
}
@Test
@Category({NeedsRunner.class, UsesTimersInParDo.class, UsesStatefulParDo.class})
public void testInGlobalWindow() {
PCollection<KV<String, Iterable<String>>> collection =
pipeline
.apply("Input data", Create.of(data))
.apply(GroupIntoBatches.<String, String>ofSize(BATCH_SIZE))
//set output coder
.setCoder(KvCoder.of(StringUtf8Coder.of(), IterableCoder.of(StringUtf8Coder.of())));
PAssert.that("Incorrect batch size in one ore more elements", collection)
.satisfies(
new SerializableFunction<Iterable<KV<String, Iterable<String>>>, Void>() {
private boolean checkBatchSizes(Iterable<KV<String, Iterable<String>>> listToCheck) {
for (KV<String, Iterable<String>> element : listToCheck) {
if (Iterables.size(element.getValue()) != BATCH_SIZE){
return false;
}
}
return true;
}
@Override
public Void apply(Iterable<KV<String, Iterable<String>>> input) {
assertTrue(checkBatchSizes(input));
return null;
}
});
PAssert.thatSingleton(
"Incorrect collection size",
collection.apply("Count", Count.<KV<String, Iterable<String>>>globally()))
.isEqualTo(NUM_ELEMENTS / BATCH_SIZE);
pipeline.run();
}
@Test
@Category({
NeedsRunner.class,
UsesTimersInParDo.class,
UsesTestStream.class,
UsesStatefulParDo.class
})
public void testInStreamingMode() {
int timestampInterval = 1;
Instant startInstant = new Instant(0L);
TestStream.Builder<KV<String, String>> streamBuilder =
TestStream.create(KvCoder.of(StringUtf8Coder.of(), StringUtf8Coder.of()))
.advanceWatermarkTo(startInstant);
long offset = 0L;
for (KV<String, String> element : data) {
streamBuilder =
streamBuilder.addElements(
TimestampedValue.of(
element,
startInstant.plus(Duration.standardSeconds(offset * timestampInterval))));
offset++;
}
final long windowDuration = 6;
TestStream<KV<String, String>> stream =
streamBuilder
.advanceWatermarkTo(startInstant.plus(Duration.standardSeconds(windowDuration - 1)))
.advanceWatermarkTo(startInstant.plus(Duration.standardSeconds(windowDuration + 1)))
.advanceWatermarkTo(startInstant.plus(Duration.standardSeconds(NUM_ELEMENTS)))
.advanceWatermarkToInfinity();
PCollection<KV<String, String>> inputCollection =
pipeline
.apply(stream)
.apply(
Window.<KV<String, String>>into(
FixedWindows.of(Duration.standardSeconds(windowDuration)))
.withAllowedLateness(Duration.millis(ALLOWED_LATENESS)));
inputCollection.apply(
ParDo.of(
new DoFn<KV<String, String>, Void>() {
@ProcessElement
public void processElement(ProcessContext c, BoundedWindow window) {
LOGGER.debug(
"*** ELEMENT: ({},{}) *** with timestamp %s in window %s",
c.element().getKey(),
c.element().getValue(),
c.timestamp().toString(),
window.toString());
}
}));
PCollection<KV<String, Iterable<String>>> outputCollection =
inputCollection
.apply(GroupIntoBatches.<String, String>ofSize(BATCH_SIZE))
.setCoder(KvCoder.of(StringUtf8Coder.of(), IterableCoder.of(StringUtf8Coder.of())));
// elements have the same key and collection is divided into windows,
// so Count.perKey values are the number of elements in windows
PCollection<KV<String, Long>> countOutput =
outputCollection.apply(
"Count elements in windows after applying GroupIntoBatches",
Count.<String, Iterable<String>>perKey());
PAssert.that("Wrong number of elements in windows after GroupIntoBatches", countOutput)
.satisfies(
new SerializableFunction<Iterable<KV<String, Long>>, Void>() {
@Override
public Void apply(Iterable<KV<String, Long>> input) {
Iterator<KV<String, Long>> inputIterator = input.iterator();
// first element
long count0 = inputIterator.next().getValue();
// window duration is 6 and batch size is 5, so there should be 2 elements in the
// window (flush because batchSize reached and for end of window reached)
assertEquals("Wrong number of elements in first window", 2, count0);
// second element
long count1 = inputIterator.next().getValue();
// collection is 10 elements, there is only 4 elements left, so there should be only
// one element in the window (flush because end of window/collection reached)
assertEquals("Wrong number of elements in second window", 1, count1);
// third element
return null;
}
});
PAssert.that("Incorrect output collection after GroupIntoBatches", outputCollection)
.satisfies(
new SerializableFunction<Iterable<KV<String, Iterable<String>>>, Void>() {
@Override
public Void apply(Iterable<KV<String, Iterable<String>>> input) {
Iterator<KV<String, Iterable<String>>> inputIterator = input.iterator();
// first element
int size0 = Iterables.size(inputIterator.next().getValue());
// window duration is 6 and batch size is 5, so output batch size should de 5
// (flush because of batchSize reached)
assertEquals("Wrong first element batch Size", 5, size0);
// second element
int size1 = Iterables.size(inputIterator.next().getValue());
// there is only one element left in the window so batch size should be 1
// (flush because of end of window reached)
assertEquals("Wrong second element batch Size", 1, size1);
// third element
int size2 = Iterables.size(inputIterator.next().getValue());
// collection is 10 elements, there is only 4 left, so batch size should be 4
// (flush because end of collection reached)
assertEquals("Wrong third element batch Size", 4, size2);
return null;
}
});
pipeline.run().waitUntilFinish();
}
}