rezarokni commented on a change in pull request #12973: URL: https://github.com/apache/beam/pull/12973#discussion_r534093432
########## File path: sdks/java/extensions/zetasketch/src/main/java/org/apache/beam/sdk/extensions/zetasketch/ApproximateCountDistinct.java ########## @@ -0,0 +1,287 @@ +/* + * 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.extensions.zetasketch; + +import com.google.auto.value.AutoValue; +import java.util.List; +import javax.annotation.Nullable; +import org.apache.beam.sdk.annotations.Experimental; +import org.apache.beam.sdk.coders.Coder; +import org.apache.beam.sdk.coders.KvCoder; +import org.apache.beam.sdk.extensions.zetasketch.HllCount.Init.Builder; +import org.apache.beam.sdk.transforms.Contextful; +import org.apache.beam.sdk.transforms.Contextful.Fn; +import org.apache.beam.sdk.transforms.MapElements; +import org.apache.beam.sdk.transforms.PTransform; +import org.apache.beam.sdk.transforms.ProcessFunction; +import org.apache.beam.sdk.transforms.display.DisplayData; +import org.apache.beam.sdk.values.KV; +import org.apache.beam.sdk.values.PCollection; +import org.apache.beam.sdk.values.TypeDescriptor; +import org.apache.beam.sdk.values.TypeDescriptors; +import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.ImmutableList; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** + * {@code PTransform}s for estimating the number of distinct elements in a {@code PCollection}, or + * the number of distinct values associated with each key in a {@code PCollection} of {@code KV}s. + * + * <p>We make use of the {@link HllCount} implementation for this transform. Please use {@link + * HllCount} directly if you need access to the sketches. + * + * <p>If the object is not one of {@link Byte[]} {@link Integer} {@link Double} {@link String} make + * use of {@link Globally#via} or {@link PerKey#via} + * + * <h3>Examples</h3> + * + * <h4>Example 1: Approximate Count of Longs {@code PCollection<Long>} and specify precision</h4> + * + * <pre>{@Code + * p.apply("Int", Create.of(ints)).apply("IntHLL", ApproximateCountDistinct.globally() + * .withPercision(PRECISION)); + * }</pre> + * + * <h4>Example 2: Approximate Count of Key Value {@code PCollection<KV<Integer,Foo>>}</h4> + * + * <pre>{@code + * PCollection<KV<Integer, Long>> result = + * p.apply("Int", Create.of(ints)).apply("LongHLL", ApproximateCountDistinct.perKey()); + * }</pre> + * + * <h4>Example 3: Approximate Count of Key Value {@code PCollection<KV<Integer,Foo>>}</h4> + * + * <pre>{@code + * PCollection<KV<Integer, Foo>> approxResultInteger = + * p.apply("Int", Create.of(Foo)) + * .apply("IntHLL", ApproximateCountDistinct.<Integer, KV<Integer, Integer>>perKey() + * .via(x -> KV.of(x.getKey(), (long) x.hashCode()))); + * }</pre> + */ +@Experimental +public class ApproximateCountDistinct { + + private static final Logger LOG = LoggerFactory.getLogger(ApproximateCountDistinct.class); + + private static final List<TypeDescriptor<?>> HLL_IMPLEMENTED_TYPES = + ImmutableList.of( + TypeDescriptors.strings(), + TypeDescriptors.longs(), + TypeDescriptors.integers(), + new TypeDescriptor<byte[]>() {}); + + public static <T> Globally<T> globally() { + return new AutoValue_ApproximateCountDistinct_Globally.Builder<T>() + .setPrecision(HllCount.DEFAULT_PRECISION) + .build(); + } + + public static <K, V> PerKey<K, V> perKey() { + return new AutoValue_ApproximateCountDistinct_PerKey.Builder<K, V>() + .setPrecision(HllCount.DEFAULT_PRECISION) + .build(); + } + + ///////////////////////////////////////////////////////////////////////////// + + /** + * {@code PTransform} for estimating the number of distinct elements in a {@code PCollection}. + * + * @param <T> the type of the elements in the input {@code PCollection} + */ + @AutoValue + public abstract static class Globally<T> extends PTransform<PCollection<T>, PCollection<Long>> { + + public abstract int getPrecision(); + + public abstract Builder<T> toBuilder(); + + @Nullable + public abstract Contextful<Fn<T, Long>> getMapping(); + + @AutoValue.Builder + public abstract static class Builder<T> { + + public abstract Builder<T> setPrecision(int precision); + + public abstract Builder<T> setMapping(Contextful<Fn<T, Long>> value); + + public abstract Globally<T> build(); + } + + public Globally<T> via(ProcessFunction<T, Long> fn) { + + return toBuilder().setMapping(Contextful.<T, Long>fn(fn)).build(); + } + + public <V> Globally<V> withPercision(Integer withPercision) { + this.toBuilder().setPrecision(withPercision).build(); Review comment: Thanx. ########## File path: sdks/java/extensions/zetasketch/src/main/java/org/apache/beam/sdk/extensions/zetasketch/ApproximateCountDistinct.java ########## @@ -0,0 +1,287 @@ +/* + * 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.extensions.zetasketch; + +import com.google.auto.value.AutoValue; +import java.util.List; +import javax.annotation.Nullable; +import org.apache.beam.sdk.annotations.Experimental; +import org.apache.beam.sdk.coders.Coder; +import org.apache.beam.sdk.coders.KvCoder; +import org.apache.beam.sdk.extensions.zetasketch.HllCount.Init.Builder; +import org.apache.beam.sdk.transforms.Contextful; +import org.apache.beam.sdk.transforms.Contextful.Fn; +import org.apache.beam.sdk.transforms.MapElements; +import org.apache.beam.sdk.transforms.PTransform; +import org.apache.beam.sdk.transforms.ProcessFunction; +import org.apache.beam.sdk.transforms.display.DisplayData; +import org.apache.beam.sdk.values.KV; +import org.apache.beam.sdk.values.PCollection; +import org.apache.beam.sdk.values.TypeDescriptor; +import org.apache.beam.sdk.values.TypeDescriptors; +import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.ImmutableList; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** + * {@code PTransform}s for estimating the number of distinct elements in a {@code PCollection}, or + * the number of distinct values associated with each key in a {@code PCollection} of {@code KV}s. + * + * <p>We make use of the {@link HllCount} implementation for this transform. Please use {@link + * HllCount} directly if you need access to the sketches. + * + * <p>If the object is not one of {@link Byte[]} {@link Integer} {@link Double} {@link String} make + * use of {@link Globally#via} or {@link PerKey#via} + * + * <h3>Examples</h3> + * + * <h4>Example 1: Approximate Count of Longs {@code PCollection<Long>} and specify precision</h4> + * + * <pre>{@Code + * p.apply("Int", Create.of(ints)).apply("IntHLL", ApproximateCountDistinct.globally() + * .withPercision(PRECISION)); + * }</pre> + * + * <h4>Example 2: Approximate Count of Key Value {@code PCollection<KV<Integer,Foo>>}</h4> + * + * <pre>{@code + * PCollection<KV<Integer, Long>> result = + * p.apply("Int", Create.of(ints)).apply("LongHLL", ApproximateCountDistinct.perKey()); Review comment: Done. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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