/**
* Applies {@code ApproximateUnique(sampleSize)} verifying that the estimation error falls within
* the maximum allowed error of {@code 2/sqrt(sampleSize)}.
*/
private static void runApproximateUniquePipeline(int sampleSize) {
Pipeline p = TestPipeline.create();
PCollection<String> input = p.apply(Create.of(TEST_LINES));
PCollection<Long> approximate = input.apply(ApproximateUnique.<String>globally(sampleSize));
final PCollectionView<Long> exact =
input
.apply(RemoveDuplicates.<String>create())
.apply(Count.<String>globally())
.apply(View.<Long>asSingleton());
PCollection<KV<Long, Long>> approximateAndExact =
approximate.apply(
ParDo.of(
new DoFn<Long, KV<Long, Long>>() {
@Override
public void processElement(ProcessContext c) {
c.output(KV.of(c.element(), c.sideInput(exact)));
}
})
.withSideInputs(exact));
DataflowAssert.that(approximateAndExact).satisfies(new VerifyEstimatePerKeyFn(sampleSize));
p.run();
}
@Test
@SuppressWarnings("unchecked")
public void testTopEmpty() {
Pipeline p = TestPipeline.create();
PCollection<String> input =
p.apply(Create.of(Arrays.asList(EMPTY_COLLECTION)).withCoder(StringUtf8Coder.of()));
PCollection<List<String>> top1 = input.apply(Top.of(1, new OrderByLength()));
PCollection<List<String>> top2 = input.apply(Top.<String>largest(2));
PCollection<List<String>> top3 = input.apply(Top.<String>smallest(3));
PCollection<KV<String, Integer>> inputTable = createEmptyInputTable(p);
PCollection<KV<String, List<Integer>>> largestPerKey =
inputTable.apply(Top.<String, Integer>largestPerKey(2));
PCollection<KV<String, List<Integer>>> smallestPerKey =
inputTable.apply(Top.<String, Integer>smallestPerKey(2));
DataflowAssert.thatSingletonIterable(top1).empty();
DataflowAssert.thatSingletonIterable(top2).empty();
DataflowAssert.thatSingletonIterable(top3).empty();
DataflowAssert.that(largestPerKey).empty();
DataflowAssert.that(smallestPerKey).empty();
p.run();
}
@Test
@SuppressWarnings("unchecked")
public void testTop() {
Pipeline p = TestPipeline.create();
PCollection<String> input =
p.apply(Create.of(Arrays.asList(COLLECTION)).withCoder(StringUtf8Coder.of()));
PCollection<List<String>> top1 = input.apply(Top.of(1, new OrderByLength()));
PCollection<List<String>> top2 = input.apply(Top.<String>largest(2));
PCollection<List<String>> top3 = input.apply(Top.<String>smallest(3));
PCollection<KV<String, Integer>> inputTable = createInputTable(p);
PCollection<KV<String, List<Integer>>> largestPerKey =
inputTable.apply(Top.<String, Integer>largestPerKey(2));
PCollection<KV<String, List<Integer>>> smallestPerKey =
inputTable.apply(Top.<String, Integer>smallestPerKey(2));
DataflowAssert.thatSingletonIterable(top1).containsInAnyOrder(Arrays.asList("bb"));
DataflowAssert.thatSingletonIterable(top2).containsInAnyOrder("z", "c");
DataflowAssert.thatSingletonIterable(top3).containsInAnyOrder("a", "bb", "c");
DataflowAssert.that(largestPerKey)
.containsInAnyOrder(KV.of("a", Arrays.asList(3, 2)), KV.of("b", Arrays.asList(100, 10)));
DataflowAssert.that(smallestPerKey)
.containsInAnyOrder(KV.of("a", Arrays.asList(1, 2)), KV.of("b", Arrays.asList(1, 10)));
p.run();
}
@Test
public void testCountConstraint() {
Pipeline p = TestPipeline.create();
PCollection<String> input =
p.apply(Create.of(Arrays.asList(COLLECTION)).withCoder(StringUtf8Coder.of()));
expectedEx.expect(IllegalArgumentException.class);
expectedEx.expectMessage(Matchers.containsString(">= 0"));
input.apply(Top.of(-1, new OrderByLength()));
}
/** Reads a large {@code PCollection<String>}. */
private PCollection<String> readPCollection(Pipeline p) {
// TODO: Read PCollection from a set of text files.
List<String> page = TestUtils.LINES;
final int pages = 1000;
ArrayList<String> file = new ArrayList<>(pages * page.size());
for (int i = 0; i < pages; i++) {
file.addAll(page);
}
assert file.size() == pages * page.size();
PCollection<String> words = p.apply(Create.of(file));
return words;
}
// This is a purely compile-time test. If the code compiles, then it worked.
@Test
public void testPerKeySerializabilityRequirement() {
Pipeline p = TestPipeline.create();
p.apply(
"CreateCollection", Create.of(Arrays.asList(COLLECTION)).withCoder(StringUtf8Coder.of()));
PCollection<KV<String, Integer>> inputTable = createInputTable(p);
inputTable.apply(Top.<String, Integer, IntegerComparator>perKey(1, new IntegerComparator()));
inputTable.apply(
"PerKey2", Top.<String, Integer, IntegerComparator2>perKey(1, new IntegerComparator2()));
}
@Test
@Category(RunnableOnService.class)
public void testApproximateUniqueWithSmallInput() {
Pipeline p = TestPipeline.create();
PCollection<Integer> input = p.apply(Create.of(Arrays.asList(1, 2, 3, 3)));
PCollection<Long> estimate = input.apply(ApproximateUnique.<Integer>globally(1000));
DataflowAssert.thatSingleton(estimate).isEqualTo(3L);
p.run();
}
/** Example test that tests a PTransform by using an in-memory input and inspecting the output. */
@Test
@Category(RunnableOnService.class)
public void testCountWords() throws Exception {
Pipeline p = TestPipeline.create();
PCollection<String> input = p.apply(Create.of(WORDS).withCoder(StringUtf8Coder.of()));
PCollection<String> output = input.apply(new CountWords())
.apply(ParDo.of(new FormatAsTextFn()));
DataflowAssert.that(output).containsInAnyOrder(COUNTS_ARRAY);
p.run();
}
@Test
@Category(RunnableOnService.class)
public void withLambdaAndTypeDescriptorShouldSucceed() {
PCollection<String> values = p.apply(Create.of("1234", "3210", "0", "-12"));
PCollection<KV<Integer, String>> kvs =
values.apply(
WithKeys.of((String s) -> Integer.valueOf(s))
.withKeyType(TypeDescriptor.of(Integer.class)));
PAssert.that(kvs)
.containsInAnyOrder(
KV.of(1234, "1234"), KV.of(0, "0"), KV.of(-12, "-12"), KV.of(3210, "3210"));
p.run();
}
@Test
public void withLambdaAndNoTypeDescriptorShouldThrow() {
PCollection<String> values = p.apply(Create.of("1234", "3210", "0", "-12"));
values.apply("ApplyKeysWithWithKeys", WithKeys.of((String s) -> Integer.valueOf(s)));
thrown.expect(IllegalStateException.class);
thrown.expectMessage("Unable to return a default Coder for ApplyKeysWithWithKeys");
thrown.expectMessage("No Coder has been manually specified");
thrown.expectMessage(containsString("Building a Coder using a registered CoderFactory failed"));
thrown.expectMessage(
containsString("Building a Coder from the @DefaultCoder annotation failed"));
thrown.expectMessage(containsString("Building a Coder from the fallback CoderProvider failed"));
p.run();
}
private void runApproximateUniqueWithDuplicates(
int elementCount, int uniqueCount, int sampleSize) {
assert elementCount >= uniqueCount;
List<Double> elements = Lists.newArrayList();
for (int i = 0; i < elementCount; i++) {
elements.add(1.0 / (i % uniqueCount + 1));
}
Collections.shuffle(elements);
Pipeline p = TestPipeline.create();
PCollection<Double> input = p.apply(Create.of(elements));
PCollection<Long> estimate = input.apply(ApproximateUnique.<Double>globally(sampleSize));
DataflowAssert.thatSingleton(estimate).satisfies(new VerifyEstimateFn(uniqueCount, sampleSize));
p.run();
}
@Test
public void testApproximateUniquePerKey() {
List<KV<Long, Long>> elements = Lists.newArrayList();
List<Long> keys = ImmutableList.of(20L, 50L, 100L);
int elementCount = 1000;
int sampleSize = 100;
// Use the key as the number of unique values.
for (long uniqueCount : keys) {
for (long value = 0; value < elementCount; value++) {
elements.add(KV.of(uniqueCount, value % uniqueCount));
}
}
Pipeline p = TestPipeline.create();
PCollection<KV<Long, Long>> input = p.apply(Create.of(elements));
PCollection<KV<Long, Long>> counts =
input.apply(ApproximateUnique.<Long, Long>perKey(sampleSize));
DataflowAssert.that(counts).satisfies(new VerifyEstimatePerKeyFn(sampleSize));
p.run();
}
private void runApproximateUniqueWithSkewedDistributions(
int elementCount, final int uniqueCount, final int sampleSize) {
List<Integer> elements = Lists.newArrayList();
// Zipf distribution with approximately elementCount items.
double s = 1 - 1.0 * uniqueCount / elementCount;
double maxCount = Math.pow(uniqueCount, s);
for (int k = 0; k < uniqueCount; k++) {
int count = Math.max(1, (int) Math.round(maxCount * Math.pow(k, -s)));
// Element k occurs count times.
for (int c = 0; c < count; c++) {
elements.add(k);
}
}
Pipeline p = TestPipeline.create();
PCollection<Integer> input = p.apply(Create.of(elements));
PCollection<Long> estimate = input.apply(ApproximateUnique.<Integer>globally(sampleSize));
DataflowAssert.thatSingleton(estimate).satisfies(new VerifyEstimateFn(uniqueCount, sampleSize));
p.run();
}
public PCollection<KV<String, Integer>> createEmptyInputTable(Pipeline p) {
return p.apply(
"CreateEmptyInputTable",
Create.of(Arrays.asList(EMPTY_TABLE))
.withCoder(KvCoder.of(StringUtf8Coder.of(), BigEndianIntegerCoder.of())));
}
