abhiy13 commented on a change in pull request #12490: URL: https://github.com/apache/beam/pull/12490#discussion_r467845547
########## File path: sdks/java/io/contextual-text-io/src/main/java/org/apache/beam/sdk/io/ContextualTextIO/ContextualTextIO.java ########## @@ -0,0 +1,554 @@ +/* + * 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.io.ContextualTextIO; + +import static org.apache.beam.sdk.io.FileIO.ReadMatches.DirectoryTreatment; +import static org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions.checkArgument; +import static org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions.checkNotNull; + +import avro.shaded.com.google.common.collect.Iterables; +import com.google.auto.value.AutoValue; +import java.nio.ByteBuffer; +import java.util.Arrays; +import java.util.HashMap; +import java.util.Map; +import java.util.SortedMap; +import java.util.TreeMap; +import javax.annotation.Nullable; +import org.apache.beam.sdk.coders.StringUtf8Coder; +import org.apache.beam.sdk.io.CompressedSource; +import org.apache.beam.sdk.io.Compression; +import org.apache.beam.sdk.io.FileBasedSource; +import org.apache.beam.sdk.io.FileIO; +import org.apache.beam.sdk.io.FileIO.MatchConfiguration; +import org.apache.beam.sdk.io.ReadAllViaFileBasedSource; +import org.apache.beam.sdk.io.fs.EmptyMatchTreatment; +import org.apache.beam.sdk.options.ValueProvider; +import org.apache.beam.sdk.options.ValueProvider.StaticValueProvider; +import org.apache.beam.sdk.schemas.NoSuchSchemaException; +import org.apache.beam.sdk.schemas.SchemaCoder; +import org.apache.beam.sdk.transforms.Create; +import org.apache.beam.sdk.transforms.DoFn; +import org.apache.beam.sdk.transforms.GroupByKey; +import org.apache.beam.sdk.transforms.PTransform; +import org.apache.beam.sdk.transforms.ParDo; +import org.apache.beam.sdk.transforms.SerializableFunction; +import org.apache.beam.sdk.transforms.View; +import org.apache.beam.sdk.transforms.Watch.Growth.TerminationCondition; +import org.apache.beam.sdk.transforms.display.DisplayData; +import org.apache.beam.sdk.values.KV; +import org.apache.beam.sdk.values.PBegin; +import org.apache.beam.sdk.values.PCollection; +import org.apache.beam.sdk.values.PCollectionView; +import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.annotations.VisibleForTesting; +import org.joda.time.Duration; + +/** + * {@link PTransform}s for reading from text files with Context + * + * <h2>Reading from text files</h2> + * + * <p>To read a {@link PCollection} from one or more text files, use {@code ContextualTextIO.read()} + * to instantiate a transform use {@link ContextualTextIO.Read#from(String)} to specify the path of + * the file(s) to be read. Alternatively, if the filenames to be read are themselves in a {@link + * PCollection} you can use {@link FileIO} to match them and {@link ContextualTextIO#readFiles()} to + * read them. + * + * <p>{@link #read} returns a {@link PCollection} of {@link LineContext LineContext}, each + * corresponding to one line of an inout UTF-8 text file (split into lines delimited by '\n', '\r', + * '\r\n', or specified delimiter see {@link ContextualTextIO.Read#withDelimiter}) + * + * <h3>Filepattern expansion and watching</h3> + * + * <p>By default, the filepatterns are expanded only once. The combination of {@link + * FileIO.Match#continuously(Duration, TerminationCondition)} and {@link #readFiles()} allow + * streaming of new files matching the filepattern(s). + * + * <p>By default, {@link #read} prohibits filepatterns that match no files, and {@link #readFiles()} + * allows them in case the filepattern contains a glob wildcard character. Use {@link + * ContextualTextIO.Read#withEmptyMatchTreatment} or {@link + * FileIO.Match#withEmptyMatchTreatment(EmptyMatchTreatment)} plus {@link #readFiles()} to configure + * this behavior. + * + * <p>Example 1: reading a file or filepattern. + * + * <pre>{@code + * Pipeline p = ...; + * + * // A simple Read of a local file (only runs locally): + * PCollection<LineContext> lines = p.apply(ContextualTextIO.read().from("/local/path/to/file.txt")); Review comment: `@DefaultSchema(AutoValueSchema.class)` `@AutoValue` `public abstract class LineContext {` I made the class based on Schema, this should be returning an object based on a Row. Am I missing something ? ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org
