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Posted to github@beam.apache.org by GitBox <gi...@apache.org> on 2020/08/20 04:45:53 UTC
[GitHub] [beam] rezarokni commented on a change in pull request #12645: [BEAM-10124] Add ContextualTextIO
rezarokni commented on a change in pull request #12645:
URL: https://github.com/apache/beam/pull/12645#discussion_r473578722
##########
File path: sdks/java/core/src/main/java/org/apache/beam/sdk/io/FileBasedSource.java
##########
@@ -130,7 +130,7 @@ protected FileBasedSource(
*
* @throws IllegalArgumentException if this source is in {@link Mode#FILEPATTERN} mode.
*/
- protected final MatchResult.Metadata getSingleFileMetadata() {
+ public final MatchResult.Metadata getSingleFileMetadata() {
Review comment:
@tvalentyn what do you think about this and the FileIO changes being done in a different commit / pr . As its a change that is potentially useful to other sources api dev and maybe easier to reason about then if tied to this larger commit?
##########
File path: sdks/java/io/contextual-text-io/src/main/java/org/apache/beam/sdk/io/contextualtextio/ContextualTextIO.java
##########
@@ -0,0 +1,594 @@
+/*
+ * 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 com.google.auto.value.AutoValue;
+import java.nio.ByteBuffer;
+import java.util.Arrays;
+import java.util.Comparator;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.SortedMap;
+import java.util.TreeMap;
+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.Count;
+import org.apache.beam.sdk.transforms.Create;
+import org.apache.beam.sdk.transforms.DoFn;
+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.checkerframework.checker.nullness.qual.Nullable;
+import org.joda.time.Duration;
+
+/**
+ * {@link PTransform}s that read text files and collect contextual information of the elements in
+ * the input.
+ *
+ * <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)} and 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 RecordWithMetadata RecordWithMetadata},
+ * 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 file:
+ * PCollection<RecordWithMetadata> lines = p.apply(ContextualTextIO.read().from("/local/path/to/file.txt"));
+ * }</pre>
+ *
+ * <p>Example 2: reading a PCollection of filenames.
+ *
+ * <pre>{@code
+ * Pipeline p = ...;
+ *
+ * // E.g. the filenames might be computed from other data in the pipeline, or
+ * // read from a data source.
+ * PCollection<String> filenames = ...;
+ *
+ * // Read all files in the collection.
+ * PCollection<RecordWithMetadata> lines =
+ * filenames
+ * .apply(FileIO.matchAll())
+ * .apply(FileIO.readMatches())
+ * .apply(ContextualTextIO.readFiles());
+ * }</pre>
+ *
+ * <p>Example 3: streaming new files matching a filepattern.
+ *
+ * <pre>{@code
+ * Pipeline p = ...;
+ *
+ * PCollection<RecordWithMetadata> lines = p.apply(ContextualTextIO.read()
+ * .from("/local/path/to/files/*")
+ * .watchForNewFiles(
+ * // Check for new files every minute
+ * Duration.standardMinutes(1),
+ * // Stop watching the filepattern if no new files appear within an hour
+ * afterTimeSinceNewOutput(Duration.standardHours(1))));
+ * }</pre>
+ *
+ * <p>Example 4: reading a file or file pattern of RFC4180-compliant CSV files with fields that may
+ * contain line breaks.
+ *
+ * <pre>{@code
+ * Pipeline p = ...;
+ *
+ * PCollection<RecordWithMetadata> lines = p.apply(ContextualTextIO.read()
+ * .from("/local/path/to/files/*.csv")
+ * .withHasMultilineCSVRecords(true));
+ * }</pre>
+ *
+ * <p>Example 5: reading while watching for new files
+ *
+ * <pre>{@code
+ * Pipeline p = ...;
+ *
+ * PCollection<RecordWithMetadata> lines = p.apply(FileIO.match()
+ * .filepattern("filepattern")
+ * .continuously(
+ * Duration.millis(100),
+ * Watch.Growth.afterTimeSinceNewOutput(Duration.standardSeconds(3))))
+ * .apply(FileIO.readMatches())
+ * .apply(ContextualTextIO.readFiles());
+ * }</pre>
+ *
+ * NOTE: Using {@link ContextualTextIO.Read#withHasMultilineCSVRecords(Boolean)} introduces a
+ * performance penalty: when this option is enabled, the input cannot be split and read in parallel.
+ *
+ * <h3>Reading a very large number of files</h3>
+ *
+ * <p>If it is known that the filepattern will match a very large number of files (e.g. tens of
+ * thousands or more), use {@link ContextualTextIO.Read#withHintMatchesManyFiles} for better
+ * performance and scalability. Note that it may decrease performance if the filepattern matches
+ * only a small number of files.
+ */
+public class ContextualTextIO {
+ private static final long DEFAULT_BUNDLE_SIZE_BYTES = 64 * 1024 * 1024L;
+
+ /**
+ * A {@link PTransform} that reads from one or more text files and returns a bounded {@link
+ * PCollection} containing one {@link RecordWithMetadata}element for each line of the input files.
+ */
+ public static Read read() {
+ return new AutoValue_ContextualTextIO_Read.Builder()
+ .setCompression(Compression.AUTO)
+ .setHintMatchesManyFiles(false)
+ .setWithoutLineNumMetadata(false)
+ .setMatchConfiguration(MatchConfiguration.create(EmptyMatchTreatment.DISALLOW))
+ .setHasMultilineCSVRecords(false)
+ .build();
+ }
+
+ /**
+ * Like {@link #read}, but reads each file in a {@link PCollection} of {@link
+ * FileIO.ReadableFile}, returned by {@link FileIO#readMatches}.
+ */
+ public static ReadFiles readFiles() {
+ return new AutoValue_ContextualTextIO_ReadFiles.Builder()
+ // 64MB is a reasonable value that allows to amortize the cost of opening files,
+ // but is not so large as to exhaust a typical runner's maximum amount of output per
+ // ProcessElement call.
+ .setDesiredBundleSizeBytes(DEFAULT_BUNDLE_SIZE_BYTES)
+ .setHasMultilineCSVRecords(false)
+ .build();
+ }
+
+ /** Implementation of {@link #read}. */
+ @AutoValue
+ public abstract static class Read extends PTransform<PBegin, PCollection<RecordWithMetadata>> {
+ abstract @Nullable ValueProvider<String> getFilepattern();
+
+ abstract MatchConfiguration getMatchConfiguration();
+
+ abstract boolean getHintMatchesManyFiles();
+
+ abstract boolean getWithoutLineNumMetadata();
+
+ abstract Compression getCompression();
+
+ abstract @Nullable Boolean getHasMultilineCSVRecords();
+
+ @SuppressWarnings("mutable") // this returns an array that can be mutated by the caller
+ abstract byte @Nullable [] getDelimiter();
+
+ abstract Builder toBuilder();
+
+ @AutoValue.Builder
+ abstract static class Builder {
+ abstract Builder setFilepattern(ValueProvider<String> filepattern);
+
+ abstract Builder setMatchConfiguration(MatchConfiguration matchConfiguration);
+
+ abstract Builder setHintMatchesManyFiles(boolean hintManyFiles);
+
+ abstract Builder setWithoutLineNumMetadata(boolean withoutLineNumMetadata);
+
+ abstract Builder setCompression(Compression compression);
+
+ abstract Builder setDelimiter(byte @Nullable [] delimiter);
+
+ abstract Builder setHasMultilineCSVRecords(Boolean hasMultilineCSVRecords);
+
+ abstract Read build();
+ }
+
+ /**
+ * Reads text from the file(s) with the given filename or filename pattern.
+ *
+ * <p>This can be a local path (if running locally), or a Google Cloud Storage filename or
+ * filename pattern of the form {@code "gs://<bucket>/<filepath>"} (if running locally or using
+ * remote execution service).
+ *
+ * <p>Standard <a href="http://docs.oracle.com/javase/tutorial/essential/io/find.html" >Java
+ * Filesystem glob patterns</a> ("*", "?", "[..]") are supported.
+ *
+ * <p>If it is known that the filepattern will match a very large number of files (at least tens
+ * of thousands), use {@link #withHintMatchesManyFiles} for better performance and scalability.
+ */
+ public Read from(String filepattern) {
+ checkArgument(filepattern != null, "filepattern can not be null");
+ return from(StaticValueProvider.of(filepattern));
+ }
+
+ /** Same as {@code from(filepattern)}, but accepting a {@link ValueProvider}. */
+ public Read from(ValueProvider<String> filepattern) {
+ checkArgument(filepattern != null, "filepattern can not be null");
+ return toBuilder().setFilepattern(filepattern).build();
+ }
+
+ /** Sets the {@link MatchConfiguration}. */
+ public Read withMatchConfiguration(MatchConfiguration matchConfiguration) {
+ return toBuilder().setMatchConfiguration(matchConfiguration).build();
+ }
+
+ /**
+ * When reading RFC4180 CSV files that have values that span multiple lines, set this to true.
+ * Note: this reduces the read performance (see: {@link ContextualTextIO}).
+ */
+ public Read withHasMultilineCSVRecords(Boolean hasMultilineCSVRecords) {
+ return toBuilder().setHasMultilineCSVRecords(hasMultilineCSVRecords).build();
+ }
+
+ /**
+ * Reads from input sources using the specified compression type.
+ *
+ * <p>If no compression type is specified, the default is {@link Compression#AUTO}.
+ */
+ public Read withCompression(Compression compression) {
+ return toBuilder().setCompression(compression).build();
+ }
+
+ /**
+ * Hints that the filepattern specified in {@link #from(String)} matches a very large number of
+ * files.
+ *
+ * <p>This hint may cause a runner to execute the transform differently, in a way that improves
+ * performance for this case, but it may worsen performance if the filepattern matches only a
+ * small number of files (e.g., in a runner that supports dynamic work rebalancing, it will
+ * happen less efficiently within individual files).
+ */
+ public Read withHintMatchesManyFiles() {
+ return toBuilder().setHintMatchesManyFiles(true).build();
+ }
+
+ /**
+ * Allows the user the opt out of getting recordNums associated with each record.
+ *
+ * <p>ContextualTextIO uses a shuffle step to assemble the recordNums for each record which may
Review comment:
I think it would be better to add something like, this will introduce a shuffle step, which will increase the resources used by the pipeline.
##########
File path: sdks/java/io/contextual-text-io/src/main/java/org/apache/beam/sdk/io/contextualtextio/ContextualTextIO.java
##########
@@ -0,0 +1,594 @@
+/*
+ * 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 com.google.auto.value.AutoValue;
+import java.nio.ByteBuffer;
+import java.util.Arrays;
+import java.util.Comparator;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.SortedMap;
+import java.util.TreeMap;
+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.Count;
+import org.apache.beam.sdk.transforms.Create;
+import org.apache.beam.sdk.transforms.DoFn;
+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.checkerframework.checker.nullness.qual.Nullable;
+import org.joda.time.Duration;
+
+/**
+ * {@link PTransform}s that read text files and collect contextual information of the elements in
+ * the input.
+ *
+ * <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)} and 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 RecordWithMetadata RecordWithMetadata},
+ * 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 file:
+ * PCollection<RecordWithMetadata> lines = p.apply(ContextualTextIO.read().from("/local/path/to/file.txt"));
+ * }</pre>
+ *
+ * <p>Example 2: reading a PCollection of filenames.
+ *
+ * <pre>{@code
+ * Pipeline p = ...;
+ *
+ * // E.g. the filenames might be computed from other data in the pipeline, or
+ * // read from a data source.
+ * PCollection<String> filenames = ...;
+ *
+ * // Read all files in the collection.
+ * PCollection<RecordWithMetadata> lines =
+ * filenames
+ * .apply(FileIO.matchAll())
+ * .apply(FileIO.readMatches())
+ * .apply(ContextualTextIO.readFiles());
+ * }</pre>
+ *
+ * <p>Example 3: streaming new files matching a filepattern.
+ *
+ * <pre>{@code
+ * Pipeline p = ...;
+ *
+ * PCollection<RecordWithMetadata> lines = p.apply(ContextualTextIO.read()
+ * .from("/local/path/to/files/*")
+ * .watchForNewFiles(
+ * // Check for new files every minute
+ * Duration.standardMinutes(1),
+ * // Stop watching the filepattern if no new files appear within an hour
+ * afterTimeSinceNewOutput(Duration.standardHours(1))));
+ * }</pre>
+ *
+ * <p>Example 4: reading a file or file pattern of RFC4180-compliant CSV files with fields that may
Review comment:
Show example of what the field may look like, I think the example from the RFC is fine.
##########
File path: sdks/java/io/contextual-text-io/src/main/java/org/apache/beam/sdk/io/contextualtextio/ContextualTextIOSource.java
##########
@@ -0,0 +1,363 @@
+/*
+ * 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 java.io.IOException;
+import java.nio.ByteBuffer;
+import java.nio.channels.ReadableByteChannel;
+import java.nio.channels.SeekableByteChannel;
+import java.util.NoSuchElementException;
+import org.apache.beam.sdk.coders.Coder;
+import org.apache.beam.sdk.io.FileBasedSource;
+import org.apache.beam.sdk.io.fs.EmptyMatchTreatment;
+import org.apache.beam.sdk.io.fs.MatchResult;
+import org.apache.beam.sdk.options.PipelineOptions;
+import org.apache.beam.sdk.options.ValueProvider;
+import org.apache.beam.sdk.schemas.NoSuchSchemaException;
+import org.apache.beam.sdk.schemas.SchemaCoder;
+import org.apache.beam.sdk.schemas.SchemaRegistry;
+import org.apache.beam.vendor.grpc.v1p26p0.com.google.protobuf.ByteString;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.annotations.VisibleForTesting;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+/**
+ * Implementation detail of {@link ContextualTextIO.Read}.
+ *
+ * <p>A {@link FileBasedSource} which can decode records delimited by newline characters.
+ *
+ * <p>This source splits the data into records using {@code UTF-8} {@code \n}, {@code \r}, or {@code
+ * \r\n} as the delimiter. This source is not strict and supports decoding the last record even if
+ * it is not delimited. Finally, no records are decoded if the stream is empty.
+ *
+ * <p>This source supports reading from any arbitrary byte position within the stream. If the
+ * starting position is not {@code 0}, then bytes are skipped until the first delimiter is found
+ * representing the beginning of the first record to be decoded.
+ */
+@VisibleForTesting
+class ContextualTextIOSource extends FileBasedSource<RecordWithMetadata> {
+ byte[] delimiter;
+
+ // Used to Override isSplittable
+ private boolean hasMultilineCSVRecords;
+
+ @Override
+ protected boolean isSplittable() throws Exception {
+ if (hasMultilineCSVRecords) {
Review comment:
Create comment explaing why we return false
##########
File path: sdks/java/io/contextual-text-io/src/main/java/org/apache/beam/sdk/io/contextualtextio/ContextualTextIO.java
##########
@@ -0,0 +1,594 @@
+/*
+ * 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 com.google.auto.value.AutoValue;
+import java.nio.ByteBuffer;
+import java.util.Arrays;
+import java.util.Comparator;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.SortedMap;
+import java.util.TreeMap;
+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.Count;
+import org.apache.beam.sdk.transforms.Create;
+import org.apache.beam.sdk.transforms.DoFn;
+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.checkerframework.checker.nullness.qual.Nullable;
+import org.joda.time.Duration;
+
+/**
+ * {@link PTransform}s that read text files and collect contextual information of the elements in
+ * the input.
+ *
+ * <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)} and 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 RecordWithMetadata RecordWithMetadata},
+ * each corresponding to one line of an inout UTF-8 text file (split into lines delimited by '\n',
Review comment:
sorry not sure if inout is a typo?
##########
File path: sdks/java/io/contextual-text-io/src/main/java/org/apache/beam/sdk/io/contextualtextio/ContextualTextIO.java
##########
@@ -0,0 +1,594 @@
+/*
+ * 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 com.google.auto.value.AutoValue;
+import java.nio.ByteBuffer;
+import java.util.Arrays;
+import java.util.Comparator;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.SortedMap;
+import java.util.TreeMap;
+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.Count;
+import org.apache.beam.sdk.transforms.Create;
+import org.apache.beam.sdk.transforms.DoFn;
+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.checkerframework.checker.nullness.qual.Nullable;
+import org.joda.time.Duration;
+
+/**
+ * {@link PTransform}s that read text files and collect contextual information of the elements in
Review comment:
Add note that ' if contextual information or multiline file reading is not needed, then make use of TextIO'
##########
File path: sdks/java/io/contextual-text-io/src/main/java/org/apache/beam/sdk/io/contextualtextio/ContextualTextIO.java
##########
@@ -0,0 +1,594 @@
+/*
+ * 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 com.google.auto.value.AutoValue;
+import java.nio.ByteBuffer;
+import java.util.Arrays;
+import java.util.Comparator;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.SortedMap;
+import java.util.TreeMap;
+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.Count;
+import org.apache.beam.sdk.transforms.Create;
+import org.apache.beam.sdk.transforms.DoFn;
+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.checkerframework.checker.nullness.qual.Nullable;
+import org.joda.time.Duration;
+
+/**
+ * {@link PTransform}s that read text files and collect contextual information of the elements in
+ * the input.
+ *
+ * <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)} and 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 RecordWithMetadata RecordWithMetadata},
+ * 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 file:
+ * PCollection<RecordWithMetadata> lines = p.apply(ContextualTextIO.read().from("/local/path/to/file.txt"));
+ * }</pre>
+ *
+ * <p>Example 2: reading a PCollection of filenames.
+ *
+ * <pre>{@code
+ * Pipeline p = ...;
+ *
+ * // E.g. the filenames might be computed from other data in the pipeline, or
+ * // read from a data source.
+ * PCollection<String> filenames = ...;
+ *
+ * // Read all files in the collection.
+ * PCollection<RecordWithMetadata> lines =
+ * filenames
+ * .apply(FileIO.matchAll())
+ * .apply(FileIO.readMatches())
+ * .apply(ContextualTextIO.readFiles());
+ * }</pre>
+ *
+ * <p>Example 3: streaming new files matching a filepattern.
+ *
+ * <pre>{@code
+ * Pipeline p = ...;
+ *
+ * PCollection<RecordWithMetadata> lines = p.apply(ContextualTextIO.read()
+ * .from("/local/path/to/files/*")
+ * .watchForNewFiles(
+ * // Check for new files every minute
+ * Duration.standardMinutes(1),
+ * // Stop watching the filepattern if no new files appear within an hour
+ * afterTimeSinceNewOutput(Duration.standardHours(1))));
+ * }</pre>
+ *
+ * <p>Example 4: reading a file or file pattern of RFC4180-compliant CSV files with fields that may
+ * contain line breaks.
+ *
+ * <pre>{@code
+ * Pipeline p = ...;
+ *
+ * PCollection<RecordWithMetadata> lines = p.apply(ContextualTextIO.read()
+ * .from("/local/path/to/files/*.csv")
+ * .withHasMultilineCSVRecords(true));
+ * }</pre>
+ *
+ * <p>Example 5: reading while watching for new files
+ *
+ * <pre>{@code
+ * Pipeline p = ...;
+ *
+ * PCollection<RecordWithMetadata> lines = p.apply(FileIO.match()
+ * .filepattern("filepattern")
+ * .continuously(
+ * Duration.millis(100),
+ * Watch.Growth.afterTimeSinceNewOutput(Duration.standardSeconds(3))))
+ * .apply(FileIO.readMatches())
+ * .apply(ContextualTextIO.readFiles());
+ * }</pre>
+ *
+ * NOTE: Using {@link ContextualTextIO.Read#withHasMultilineCSVRecords(Boolean)} introduces a
Review comment:
maybe change to :
when this option is used a single reader will be used to process the file, rather than multiple readers which can read from different offsets. For a large file this can result in lower performance.
##########
File path: sdks/java/io/contextual-text-io/src/main/java/org/apache/beam/sdk/io/contextualtextio/ContextualTextIO.java
##########
@@ -0,0 +1,594 @@
+/*
+ * 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 com.google.auto.value.AutoValue;
+import java.nio.ByteBuffer;
+import java.util.Arrays;
+import java.util.Comparator;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.SortedMap;
+import java.util.TreeMap;
+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.Count;
+import org.apache.beam.sdk.transforms.Create;
+import org.apache.beam.sdk.transforms.DoFn;
+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.checkerframework.checker.nullness.qual.Nullable;
+import org.joda.time.Duration;
+
+/**
+ * {@link PTransform}s that read text files and collect contextual information of the elements in
+ * the input.
+ *
+ * <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)} and 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 RecordWithMetadata RecordWithMetadata},
+ * 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 file:
+ * PCollection<RecordWithMetadata> lines = p.apply(ContextualTextIO.read().from("/local/path/to/file.txt"));
+ * }</pre>
+ *
+ * <p>Example 2: reading a PCollection of filenames.
+ *
+ * <pre>{@code
+ * Pipeline p = ...;
+ *
+ * // E.g. the filenames might be computed from other data in the pipeline, or
+ * // read from a data source.
+ * PCollection<String> filenames = ...;
+ *
+ * // Read all files in the collection.
+ * PCollection<RecordWithMetadata> lines =
+ * filenames
+ * .apply(FileIO.matchAll())
+ * .apply(FileIO.readMatches())
+ * .apply(ContextualTextIO.readFiles());
+ * }</pre>
+ *
+ * <p>Example 3: streaming new files matching a filepattern.
+ *
+ * <pre>{@code
+ * Pipeline p = ...;
+ *
+ * PCollection<RecordWithMetadata> lines = p.apply(ContextualTextIO.read()
+ * .from("/local/path/to/files/*")
+ * .watchForNewFiles(
+ * // Check for new files every minute
+ * Duration.standardMinutes(1),
+ * // Stop watching the filepattern if no new files appear within an hour
+ * afterTimeSinceNewOutput(Duration.standardHours(1))));
+ * }</pre>
+ *
+ * <p>Example 4: reading a file or file pattern of RFC4180-compliant CSV files with fields that may
+ * contain line breaks.
+ *
+ * <pre>{@code
+ * Pipeline p = ...;
+ *
+ * PCollection<RecordWithMetadata> lines = p.apply(ContextualTextIO.read()
+ * .from("/local/path/to/files/*.csv")
+ * .withHasMultilineCSVRecords(true));
+ * }</pre>
+ *
+ * <p>Example 5: reading while watching for new files
+ *
+ * <pre>{@code
+ * Pipeline p = ...;
+ *
+ * PCollection<RecordWithMetadata> lines = p.apply(FileIO.match()
+ * .filepattern("filepattern")
+ * .continuously(
+ * Duration.millis(100),
+ * Watch.Growth.afterTimeSinceNewOutput(Duration.standardSeconds(3))))
+ * .apply(FileIO.readMatches())
+ * .apply(ContextualTextIO.readFiles());
+ * }</pre>
+ *
+ * NOTE: Using {@link ContextualTextIO.Read#withHasMultilineCSVRecords(Boolean)} introduces a
+ * performance penalty: when this option is enabled, the input cannot be split and read in parallel.
+ *
+ * <h3>Reading a very large number of files</h3>
+ *
+ * <p>If it is known that the filepattern will match a very large number of files (e.g. tens of
+ * thousands or more), use {@link ContextualTextIO.Read#withHintMatchesManyFiles} for better
+ * performance and scalability. Note that it may decrease performance if the filepattern matches
+ * only a small number of files.
+ */
+public class ContextualTextIO {
+ private static final long DEFAULT_BUNDLE_SIZE_BYTES = 64 * 1024 * 1024L;
+
+ /**
+ * A {@link PTransform} that reads from one or more text files and returns a bounded {@link
Review comment:
explain the other config options used in the example, WithoutLineNumMetadata etc... Also as we have changed from lineContext to Record Contexr should this now be WithoutRecordMetadata?
@tvalentyn fyi
##########
File path: sdks/java/io/contextual-text-io/src/main/java/org/apache/beam/sdk/io/contextualtextio/ContextualTextIO.java
##########
@@ -0,0 +1,594 @@
+/*
+ * 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 com.google.auto.value.AutoValue;
+import java.nio.ByteBuffer;
+import java.util.Arrays;
+import java.util.Comparator;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.SortedMap;
+import java.util.TreeMap;
+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.Count;
+import org.apache.beam.sdk.transforms.Create;
+import org.apache.beam.sdk.transforms.DoFn;
+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.checkerframework.checker.nullness.qual.Nullable;
+import org.joda.time.Duration;
+
+/**
+ * {@link PTransform}s that read text files and collect contextual information of the elements in
+ * the input.
+ *
+ * <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)} and 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 RecordWithMetadata RecordWithMetadata},
+ * 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 file:
+ * PCollection<RecordWithMetadata> lines = p.apply(ContextualTextIO.read().from("/local/path/to/file.txt"));
+ * }</pre>
+ *
+ * <p>Example 2: reading a PCollection of filenames.
+ *
+ * <pre>{@code
+ * Pipeline p = ...;
+ *
+ * // E.g. the filenames might be computed from other data in the pipeline, or
+ * // read from a data source.
+ * PCollection<String> filenames = ...;
+ *
+ * // Read all files in the collection.
+ * PCollection<RecordWithMetadata> lines =
+ * filenames
+ * .apply(FileIO.matchAll())
+ * .apply(FileIO.readMatches())
+ * .apply(ContextualTextIO.readFiles());
+ * }</pre>
+ *
+ * <p>Example 3: streaming new files matching a filepattern.
+ *
+ * <pre>{@code
+ * Pipeline p = ...;
+ *
+ * PCollection<RecordWithMetadata> lines = p.apply(ContextualTextIO.read()
+ * .from("/local/path/to/files/*")
+ * .watchForNewFiles(
+ * // Check for new files every minute
+ * Duration.standardMinutes(1),
+ * // Stop watching the filepattern if no new files appear within an hour
+ * afterTimeSinceNewOutput(Duration.standardHours(1))));
+ * }</pre>
+ *
+ * <p>Example 4: reading a file or file pattern of RFC4180-compliant CSV files with fields that may
+ * contain line breaks.
+ *
+ * <pre>{@code
+ * Pipeline p = ...;
+ *
+ * PCollection<RecordWithMetadata> lines = p.apply(ContextualTextIO.read()
+ * .from("/local/path/to/files/*.csv")
+ * .withHasMultilineCSVRecords(true));
+ * }</pre>
+ *
+ * <p>Example 5: reading while watching for new files
+ *
+ * <pre>{@code
+ * Pipeline p = ...;
+ *
+ * PCollection<RecordWithMetadata> lines = p.apply(FileIO.match()
+ * .filepattern("filepattern")
+ * .continuously(
+ * Duration.millis(100),
+ * Watch.Growth.afterTimeSinceNewOutput(Duration.standardSeconds(3))))
+ * .apply(FileIO.readMatches())
+ * .apply(ContextualTextIO.readFiles());
+ * }</pre>
+ *
+ * NOTE: Using {@link ContextualTextIO.Read#withHasMultilineCSVRecords(Boolean)} introduces a
+ * performance penalty: when this option is enabled, the input cannot be split and read in parallel.
+ *
+ * <h3>Reading a very large number of files</h3>
+ *
+ * <p>If it is known that the filepattern will match a very large number of files (e.g. tens of
+ * thousands or more), use {@link ContextualTextIO.Read#withHintMatchesManyFiles} for better
+ * performance and scalability. Note that it may decrease performance if the filepattern matches
+ * only a small number of files.
+ */
+public class ContextualTextIO {
+ private static final long DEFAULT_BUNDLE_SIZE_BYTES = 64 * 1024 * 1024L;
+
+ /**
+ * A {@link PTransform} that reads from one or more text files and returns a bounded {@link
+ * PCollection} containing one {@link RecordWithMetadata}element for each line of the input files.
+ */
+ public static Read read() {
+ return new AutoValue_ContextualTextIO_Read.Builder()
+ .setCompression(Compression.AUTO)
+ .setHintMatchesManyFiles(false)
+ .setWithoutLineNumMetadata(false)
+ .setMatchConfiguration(MatchConfiguration.create(EmptyMatchTreatment.DISALLOW))
+ .setHasMultilineCSVRecords(false)
+ .build();
+ }
+
+ /**
+ * Like {@link #read}, but reads each file in a {@link PCollection} of {@link
+ * FileIO.ReadableFile}, returned by {@link FileIO#readMatches}.
+ */
+ public static ReadFiles readFiles() {
Review comment:
If the default is false, do we need to set it for every call?
##########
File path: sdks/java/io/contextual-text-io/src/main/java/org/apache/beam/sdk/io/contextualtextio/ContextualTextIOSource.java
##########
@@ -0,0 +1,363 @@
+/*
+ * 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 java.io.IOException;
+import java.nio.ByteBuffer;
+import java.nio.channels.ReadableByteChannel;
+import java.nio.channels.SeekableByteChannel;
+import java.util.NoSuchElementException;
+import org.apache.beam.sdk.coders.Coder;
+import org.apache.beam.sdk.io.FileBasedSource;
+import org.apache.beam.sdk.io.fs.EmptyMatchTreatment;
+import org.apache.beam.sdk.io.fs.MatchResult;
+import org.apache.beam.sdk.options.PipelineOptions;
+import org.apache.beam.sdk.options.ValueProvider;
+import org.apache.beam.sdk.schemas.NoSuchSchemaException;
+import org.apache.beam.sdk.schemas.SchemaCoder;
+import org.apache.beam.sdk.schemas.SchemaRegistry;
+import org.apache.beam.vendor.grpc.v1p26p0.com.google.protobuf.ByteString;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.annotations.VisibleForTesting;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+/**
+ * Implementation detail of {@link ContextualTextIO.Read}.
+ *
+ * <p>A {@link FileBasedSource} which can decode records delimited by newline characters.
+ *
+ * <p>This source splits the data into records using {@code UTF-8} {@code \n}, {@code \r}, or {@code
+ * \r\n} as the delimiter. This source is not strict and supports decoding the last record even if
+ * it is not delimited. Finally, no records are decoded if the stream is empty.
+ *
+ * <p>This source supports reading from any arbitrary byte position within the stream. If the
+ * starting position is not {@code 0}, then bytes are skipped until the first delimiter is found
+ * representing the beginning of the first record to be decoded.
+ */
+@VisibleForTesting
+class ContextualTextIOSource extends FileBasedSource<RecordWithMetadata> {
+ byte[] delimiter;
+
+ // Used to Override isSplittable
+ private boolean hasMultilineCSVRecords;
+
+ @Override
+ protected boolean isSplittable() throws Exception {
+ if (hasMultilineCSVRecords) {
+ return false;
+ }
+ return super.isSplittable();
+ }
+
+ ContextualTextIOSource(
+ ValueProvider<String> fileSpec,
+ EmptyMatchTreatment emptyMatchTreatment,
+ byte[] delimiter,
+ boolean hasMultilineCSVRecords) {
+ super(fileSpec, emptyMatchTreatment, 1L);
+ this.delimiter = delimiter;
+ this.hasMultilineCSVRecords = hasMultilineCSVRecords;
+ }
+
+ private ContextualTextIOSource(
+ MatchResult.Metadata metadata,
+ long start,
+ long end,
+ byte[] delimiter,
+ boolean hasMultilineCSVRecords) {
+ super(metadata, 1L, start, end);
+ this.delimiter = delimiter;
+ this.hasMultilineCSVRecords = hasMultilineCSVRecords;
+ }
+
+ @Override
+ protected FileBasedSource<RecordWithMetadata> createForSubrangeOfFile(
+ MatchResult.Metadata metadata, long start, long end) {
+ return new ContextualTextIOSource(metadata, start, end, delimiter, hasMultilineCSVRecords);
+ }
+
+ @Override
+ protected FileBasedReader<RecordWithMetadata> createSingleFileReader(PipelineOptions options) {
+ return new MultiLineTextBasedReader(this, delimiter, hasMultilineCSVRecords);
+ }
+
+ @Override
+ public Coder<RecordWithMetadata> getOutputCoder() {
+ SchemaCoder<RecordWithMetadata> coder = null;
+ try {
+ coder = SchemaRegistry.createDefault().getSchemaCoder(RecordWithMetadata.class);
+ } catch (NoSuchSchemaException e) {
+ System.out.println("No Coder!");
+ }
+ return coder;
+ }
+
+ /**
+ * A {@link FileBasedReader FileBasedReader} which can decode records delimited by delimiter
+ * characters.
+ *
+ * <p>See {@link ContextualTextIOSource } for further details.
+ */
+ @VisibleForTesting
+ static class MultiLineTextBasedReader extends FileBasedReader<RecordWithMetadata> {
+ public static final int READ_BUFFER_SIZE = 8192;
+ private static final ByteString UTF8_BOM =
+ ByteString.copyFrom(new byte[] {(byte) 0xEF, (byte) 0xBB, (byte) 0xBF});
+ private final ByteBuffer readBuffer = ByteBuffer.allocate(READ_BUFFER_SIZE);
+ private ByteString buffer;
+ private int startOfDelimiterInBuffer;
+ private int endOfDelimiterInBuffer;
+ private long startOfRecord;
+ private volatile long startOfNextRecord;
+ private volatile boolean eof;
+ private volatile boolean elementIsPresent;
+ private @Nullable RecordWithMetadata currentValue;
+ private @Nullable ReadableByteChannel inChannel;
+ private byte @Nullable [] delimiter;
+
+ // Add to override the isSplittable
+ private boolean hasRFC4180MultiLineColumn;
+
+ private long startingOffset;
+ private long readerlineNum;
+
+ private MultiLineTextBasedReader(
+ ContextualTextIOSource source, byte[] delimiter, boolean hasRFC4180MultiLineColumn) {
+ super(source);
+ buffer = ByteString.EMPTY;
+ this.delimiter = delimiter;
+ this.hasRFC4180MultiLineColumn = hasRFC4180MultiLineColumn;
+ startingOffset = getCurrentSource().getStartOffset(); // Start offset;
+ }
+
+ @Override
+ protected long getCurrentOffset() throws NoSuchElementException {
+ if (!elementIsPresent) {
+ throw new NoSuchElementException();
+ }
+ return startOfRecord;
+ }
+
+ @Override
+ public long getSplitPointsRemaining() {
+ if (isStarted() && startOfNextRecord >= getCurrentSource().getEndOffset()) {
+ return isDone() ? 0 : 1;
+ }
+ return super.getSplitPointsRemaining();
+ }
+
+ @Override
+ public RecordWithMetadata getCurrent() throws NoSuchElementException {
+ if (!elementIsPresent) {
+ throw new NoSuchElementException();
+ }
+ return currentValue;
+ }
+
+ @Override
+ protected void startReading(ReadableByteChannel channel) throws IOException {
+ this.inChannel = channel;
+ // If the first offset is greater than zero, we need to skip bytes until we see our
+ // first delimiter.
+ long startOffset = getCurrentSource().getStartOffset();
+ if (startOffset > 0) {
+ Preconditions.checkState(
+ channel instanceof SeekableByteChannel,
+ "%s only supports reading from a SeekableByteChannel when given a start offset"
+ + " greater than 0.",
+ ContextualTextIOSource.class.getSimpleName());
+ long requiredPosition = startOffset - 1;
+ if (delimiter != null && startOffset >= delimiter.length) {
+ // we need to move back the offset of at worse delimiter.size to be sure to see
+ // all the bytes of the delimiter in the call to findDelimiterBounds() below
+ requiredPosition = startOffset - delimiter.length;
+ }
+ ((SeekableByteChannel) channel).position(requiredPosition);
+ findDelimiterBoundsWithMultiLineCheck();
+ buffer = buffer.substring(endOfDelimiterInBuffer);
+ startOfNextRecord = requiredPosition + endOfDelimiterInBuffer;
+ endOfDelimiterInBuffer = 0;
+ startOfDelimiterInBuffer = 0;
+ }
+ }
+
+ private void findDelimiterBoundsWithMultiLineCheck() throws IOException {
+ findDelimiterBounds();
+ }
+
+ /**
+ * Locates the start position and end position of the next delimiter. Will consume the channel
+ * till either EOF or the delimiter bounds are found.
+ *
+ * <p>If {@link ContextualTextIOSource#hasMultilineCSVRecords} is set then the behaviour will
+ * change from the standard read seen in {@link org.apache.beam.sdk.io.TextIO}. The assumption
+ * when {@link ContextualTextIOSource#hasMultilineCSVRecords} is set is that the file is being
+ * read with a single thread.
+ *
+ * <p>This fills the buffer and updates the positions as follows:
+ *
+ * <pre>{@code
+ * ------------------------------------------------------
+ * | element bytes | delimiter bytes | unconsumed bytes |
+ * ------------------------------------------------------
+ * 0 start of end of buffer
+ * delimiter delimiter size
+ * in buffer in buffer
+ * }</pre>
+ */
+ private void findDelimiterBounds() throws IOException {
+ int bytePositionInBuffer = 0;
+ boolean doubleQuoteClosed = true;
+
+ while (true) {
+ if (!tryToEnsureNumberOfBytesInBuffer(bytePositionInBuffer + 1)) {
+ startOfDelimiterInBuffer = endOfDelimiterInBuffer = bytePositionInBuffer;
+ break;
+ }
+
+ byte currentByte = buffer.byteAt(bytePositionInBuffer);
+ if (hasRFC4180MultiLineColumn) {
+ // Check if we are inside an open Quote
+ if (currentByte == '"') {
+ doubleQuoteClosed = !doubleQuoteClosed;
+ }
+ } else {
+ doubleQuoteClosed = true;
+ }
+
+ if (delimiter == null) {
+ // default delimiter
+ if (currentByte == '\n') {
+ startOfDelimiterInBuffer = bytePositionInBuffer;
+ endOfDelimiterInBuffer = startOfDelimiterInBuffer + 1;
+ if (doubleQuoteClosed) {
+ break;
+ }
+ } else if (currentByte == '\r') {
+ startOfDelimiterInBuffer = bytePositionInBuffer;
+ endOfDelimiterInBuffer = startOfDelimiterInBuffer + 1;
+ if (tryToEnsureNumberOfBytesInBuffer(bytePositionInBuffer + 2)) {
+ currentByte = buffer.byteAt(bytePositionInBuffer + 1);
+ if (currentByte == '\n') {
+ endOfDelimiterInBuffer += 1;
+ }
+ }
+ if (doubleQuoteClosed) {
+ break;
+ }
+ }
+ } else {
+ // when the user defines a delimiter
+ int i = 0;
+ startOfDelimiterInBuffer = endOfDelimiterInBuffer = bytePositionInBuffer;
+ while ((i < delimiter.length) && (currentByte == delimiter[i])) {
+ // read next byte;
+ i++;
+ if (tryToEnsureNumberOfBytesInBuffer(bytePositionInBuffer + i + 1)) {
+ currentByte = buffer.byteAt(bytePositionInBuffer + i);
+ } else {
+ // corner case: delimiter truncate at the end of file
+ startOfDelimiterInBuffer = endOfDelimiterInBuffer = bytePositionInBuffer;
+ break;
+ }
+ }
+ if (i == delimiter.length) {
+ endOfDelimiterInBuffer = bytePositionInBuffer + i;
+ if (doubleQuoteClosed) {
+ break;
+ }
+ }
+ }
+ bytePositionInBuffer += 1;
+ }
+ }
+
+ @Override
+ protected boolean readNextRecord() throws IOException {
+ startOfRecord = startOfNextRecord;
+
+ findDelimiterBoundsWithMultiLineCheck();
+
+ // If we have reached EOF file and consumed all of the buffer then we know
+ // that there are no more records.
+ if (eof && buffer.isEmpty()) {
+ elementIsPresent = false;
+ return false;
+ }
+
+ decodeCurrentElement();
+ startOfNextRecord = startOfRecord + endOfDelimiterInBuffer;
+ return true;
+ }
+
+ /**
+ * Decodes the current element updating the buffer to only contain the unconsumed bytes.
+ *
+ * <p>This invalidates the currently stored {@code startOfDelimiterInBuffer} and {@code
+ * endOfDelimiterInBuffer}.
+ */
+ private void decodeCurrentElement() throws IOException {
+ ByteString dataToDecode = buffer.substring(0, startOfDelimiterInBuffer);
+ // If present, the UTF8 Byte Order Mark (BOM) will be removed.
+ if (startOfRecord == 0 && dataToDecode.startsWith(UTF8_BOM)) {
+ dataToDecode = dataToDecode.substring(UTF8_BOM.size());
+ }
+
+ /////////////////////////////////////////////
+
+ // Data of the Current Line
+ // dataToDecode.toStringUtf8();
+
+ // The line num is:
+ Long lineUniqueLineNum = readerlineNum++;
+ // The Complete FileName (with uri if this is a web url eg: temp/abc.txt) is:
+ String fileName = getCurrentSource().getSingleFileMetadata().resourceId().toString();
Review comment:
@tvalentyn @abhiy13 what do you think of having a getUri field and a getFileName field, where the filename is just the filename,
My concern is that if we have a very long URI with a file that contains a couple of cols of ints, we are massively expanding the size of the output. In the future having a id + sideinput with the filenames would solve this issue better. But this would be a nice way to reduce this problem?
##########
File path: sdks/java/io/contextual-text-io/src/main/java/org/apache/beam/sdk/io/contextualtextio/ContextualTextIO.java
##########
@@ -0,0 +1,594 @@
+/*
+ * 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 com.google.auto.value.AutoValue;
+import java.nio.ByteBuffer;
+import java.util.Arrays;
+import java.util.Comparator;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.SortedMap;
+import java.util.TreeMap;
+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.Count;
+import org.apache.beam.sdk.transforms.Create;
+import org.apache.beam.sdk.transforms.DoFn;
+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.checkerframework.checker.nullness.qual.Nullable;
+import org.joda.time.Duration;
+
+/**
+ * {@link PTransform}s that read text files and collect contextual information of the elements in
+ * the input.
+ *
+ * <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)} and 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 RecordWithMetadata RecordWithMetadata},
+ * 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 file:
+ * PCollection<RecordWithMetadata> lines = p.apply(ContextualTextIO.read().from("/local/path/to/file.txt"));
+ * }</pre>
+ *
+ * <p>Example 2: reading a PCollection of filenames.
+ *
+ * <pre>{@code
+ * Pipeline p = ...;
+ *
+ * // E.g. the filenames might be computed from other data in the pipeline, or
+ * // read from a data source.
+ * PCollection<String> filenames = ...;
+ *
+ * // Read all files in the collection.
+ * PCollection<RecordWithMetadata> lines =
+ * filenames
+ * .apply(FileIO.matchAll())
+ * .apply(FileIO.readMatches())
+ * .apply(ContextualTextIO.readFiles());
+ * }</pre>
+ *
+ * <p>Example 3: streaming new files matching a filepattern.
+ *
+ * <pre>{@code
+ * Pipeline p = ...;
+ *
+ * PCollection<RecordWithMetadata> lines = p.apply(ContextualTextIO.read()
+ * .from("/local/path/to/files/*")
+ * .watchForNewFiles(
+ * // Check for new files every minute
+ * Duration.standardMinutes(1),
+ * // Stop watching the filepattern if no new files appear within an hour
+ * afterTimeSinceNewOutput(Duration.standardHours(1))));
+ * }</pre>
+ *
+ * <p>Example 4: reading a file or file pattern of RFC4180-compliant CSV files with fields that may
+ * contain line breaks.
+ *
+ * <pre>{@code
+ * Pipeline p = ...;
+ *
+ * PCollection<RecordWithMetadata> lines = p.apply(ContextualTextIO.read()
+ * .from("/local/path/to/files/*.csv")
+ * .withHasMultilineCSVRecords(true));
+ * }</pre>
+ *
+ * <p>Example 5: reading while watching for new files
+ *
+ * <pre>{@code
+ * Pipeline p = ...;
+ *
+ * PCollection<RecordWithMetadata> lines = p.apply(FileIO.match()
+ * .filepattern("filepattern")
+ * .continuously(
+ * Duration.millis(100),
+ * Watch.Growth.afterTimeSinceNewOutput(Duration.standardSeconds(3))))
+ * .apply(FileIO.readMatches())
+ * .apply(ContextualTextIO.readFiles());
+ * }</pre>
+ *
+ * NOTE: Using {@link ContextualTextIO.Read#withHasMultilineCSVRecords(Boolean)} introduces a
+ * performance penalty: when this option is enabled, the input cannot be split and read in parallel.
+ *
+ * <h3>Reading a very large number of files</h3>
+ *
+ * <p>If it is known that the filepattern will match a very large number of files (e.g. tens of
+ * thousands or more), use {@link ContextualTextIO.Read#withHintMatchesManyFiles} for better
+ * performance and scalability. Note that it may decrease performance if the filepattern matches
+ * only a small number of files.
+ */
+public class ContextualTextIO {
+ private static final long DEFAULT_BUNDLE_SIZE_BYTES = 64 * 1024 * 1024L;
+
+ /**
+ * A {@link PTransform} that reads from one or more text files and returns a bounded {@link
+ * PCollection} containing one {@link RecordWithMetadata}element for each line of the input files.
+ */
+ public static Read read() {
+ return new AutoValue_ContextualTextIO_Read.Builder()
+ .setCompression(Compression.AUTO)
+ .setHintMatchesManyFiles(false)
+ .setWithoutLineNumMetadata(false)
+ .setMatchConfiguration(MatchConfiguration.create(EmptyMatchTreatment.DISALLOW))
+ .setHasMultilineCSVRecords(false)
+ .build();
+ }
+
+ /**
+ * Like {@link #read}, but reads each file in a {@link PCollection} of {@link
+ * FileIO.ReadableFile}, returned by {@link FileIO#readMatches}.
+ */
+ public static ReadFiles readFiles() {
+ return new AutoValue_ContextualTextIO_ReadFiles.Builder()
+ // 64MB is a reasonable value that allows to amortize the cost of opening files,
+ // but is not so large as to exhaust a typical runner's maximum amount of output per
+ // ProcessElement call.
+ .setDesiredBundleSizeBytes(DEFAULT_BUNDLE_SIZE_BYTES)
+ .setHasMultilineCSVRecords(false)
+ .build();
+ }
+
+ /** Implementation of {@link #read}. */
+ @AutoValue
+ public abstract static class Read extends PTransform<PBegin, PCollection<RecordWithMetadata>> {
+ abstract @Nullable ValueProvider<String> getFilepattern();
+
+ abstract MatchConfiguration getMatchConfiguration();
+
+ abstract boolean getHintMatchesManyFiles();
+
+ abstract boolean getWithoutLineNumMetadata();
+
+ abstract Compression getCompression();
+
+ abstract @Nullable Boolean getHasMultilineCSVRecords();
+
+ @SuppressWarnings("mutable") // this returns an array that can be mutated by the caller
+ abstract byte @Nullable [] getDelimiter();
+
+ abstract Builder toBuilder();
+
+ @AutoValue.Builder
+ abstract static class Builder {
+ abstract Builder setFilepattern(ValueProvider<String> filepattern);
+
+ abstract Builder setMatchConfiguration(MatchConfiguration matchConfiguration);
+
+ abstract Builder setHintMatchesManyFiles(boolean hintManyFiles);
+
+ abstract Builder setWithoutLineNumMetadata(boolean withoutLineNumMetadata);
+
+ abstract Builder setCompression(Compression compression);
+
+ abstract Builder setDelimiter(byte @Nullable [] delimiter);
+
+ abstract Builder setHasMultilineCSVRecords(Boolean hasMultilineCSVRecords);
+
+ abstract Read build();
+ }
+
+ /**
+ * Reads text from the file(s) with the given filename or filename pattern.
+ *
+ * <p>This can be a local path (if running locally), or a Google Cloud Storage filename or
+ * filename pattern of the form {@code "gs://<bucket>/<filepath>"} (if running locally or using
+ * remote execution service).
+ *
+ * <p>Standard <a href="http://docs.oracle.com/javase/tutorial/essential/io/find.html" >Java
+ * Filesystem glob patterns</a> ("*", "?", "[..]") are supported.
+ *
+ * <p>If it is known that the filepattern will match a very large number of files (at least tens
+ * of thousands), use {@link #withHintMatchesManyFiles} for better performance and scalability.
+ */
+ public Read from(String filepattern) {
+ checkArgument(filepattern != null, "filepattern can not be null");
+ return from(StaticValueProvider.of(filepattern));
+ }
+
+ /** Same as {@code from(filepattern)}, but accepting a {@link ValueProvider}. */
+ public Read from(ValueProvider<String> filepattern) {
+ checkArgument(filepattern != null, "filepattern can not be null");
+ return toBuilder().setFilepattern(filepattern).build();
+ }
+
+ /** Sets the {@link MatchConfiguration}. */
+ public Read withMatchConfiguration(MatchConfiguration matchConfiguration) {
+ return toBuilder().setMatchConfiguration(matchConfiguration).build();
+ }
+
+ /**
+ * When reading RFC4180 CSV files that have values that span multiple lines, set this to true.
+ * Note: this reduces the read performance (see: {@link ContextualTextIO}).
+ */
+ public Read withHasMultilineCSVRecords(Boolean hasMultilineCSVRecords) {
+ return toBuilder().setHasMultilineCSVRecords(hasMultilineCSVRecords).build();
+ }
+
+ /**
+ * Reads from input sources using the specified compression type.
+ *
+ * <p>If no compression type is specified, the default is {@link Compression#AUTO}.
+ */
+ public Read withCompression(Compression compression) {
+ return toBuilder().setCompression(compression).build();
+ }
+
+ /**
+ * Hints that the filepattern specified in {@link #from(String)} matches a very large number of
+ * files.
+ *
+ * <p>This hint may cause a runner to execute the transform differently, in a way that improves
+ * performance for this case, but it may worsen performance if the filepattern matches only a
+ * small number of files (e.g., in a runner that supports dynamic work rebalancing, it will
+ * happen less efficiently within individual files).
+ */
+ public Read withHintMatchesManyFiles() {
+ return toBuilder().setHintMatchesManyFiles(true).build();
+ }
+
+ /**
+ * Allows the user the opt out of getting recordNums associated with each record.
+ *
+ * <p>ContextualTextIO uses a shuffle step to assemble the recordNums for each record which may
+ * result in some performance loss.
+ *
+ * <p>Use this when metadata like fileNames are required and their position/order can be
+ * ignored.
+ */
+ public Read withoutLineNumMetadata() {
+ return toBuilder().setWithoutLineNumMetadata(true).build();
+ }
+
+ /** See {@link MatchConfiguration#withEmptyMatchTreatment}. */
+ public Read withEmptyMatchTreatment(EmptyMatchTreatment treatment) {
+ return withMatchConfiguration(getMatchConfiguration().withEmptyMatchTreatment(treatment));
+ }
+
+ /** Set the custom delimiter to be used in place of the default ones ('\r', '\n' or '\r\n'). */
+ public Read withDelimiter(byte[] delimiter) {
+ checkArgument(delimiter != null, "delimiter can not be null");
+ checkArgument(!isSelfOverlapping(delimiter), "delimiter must not self-overlap");
+ return toBuilder().setDelimiter(delimiter).build();
+ }
+
+ static boolean isSelfOverlapping(byte[] s) {
+ // s self-overlaps if v exists such as s = vu = wv with u and w non empty
+ for (int i = 1; i < s.length - 1; ++i) {
+ if (ByteBuffer.wrap(s, 0, i).equals(ByteBuffer.wrap(s, s.length - i, i))) {
+ return true;
+ }
+ }
+ return false;
+ }
+
+ @Override
+ public PCollection<RecordWithMetadata> expand(PBegin input) {
+ checkNotNull(
+ getFilepattern(), "need to set the filepattern of a ContextualTextIO.Read transform");
+ PCollection<RecordWithMetadata> lines = null;
+ if (getMatchConfiguration().getWatchInterval() == null && !getHintMatchesManyFiles()) {
+ lines = input.apply("Read", org.apache.beam.sdk.io.Read.from(getSource()));
+ } else {
+ // All other cases go through FileIO + ReadFiles
+ lines =
+ input
+ .apply(
+ "Create filepattern", Create.ofProvider(getFilepattern(), StringUtf8Coder.of()))
+ .apply("Match All", FileIO.matchAll().withConfiguration(getMatchConfiguration()))
+ .apply(
+ "Read Matches",
+ FileIO.readMatches()
+ .withCompression(getCompression())
+ .withDirectoryTreatment(DirectoryTreatment.PROHIBIT))
+ .apply("Via ReadFiles", readFiles().withDelimiter(getDelimiter()));
+ }
+
+ // Check if the user decided to opt out of recordNums associated with records
+ if (getWithoutLineNumMetadata()) {
+ return lines;
+ }
+
+ // At this point the line number in RecordWithMetadata contains the relative line offset from
+ // the
+ // beginning of the read range.
+
+ // To compute the absolute position from the beginning of the input,
+ // we group the lines within the same ranges, and evaluate the size of each range.
+
+ PCollection<KV<KV<String, Long>, RecordWithMetadata>> linesGroupedByFileAndRange =
+ lines.apply("AddFileNameAndRange", ParDo.of(new AddFileNameAndRange()));
+
+ PCollectionView<Map<KV<String, Long>, Long>> rangeSizes =
+ linesGroupedByFileAndRange
+ .apply("CountLinesForEachFileRange", Count.perKey())
+ .apply("SizesAsView", View.asMap());
+
+ // Get Pipeline to create a dummy PCollection with one element to help compute the lines
+ // before each Range
+ PCollection<Integer> singletonPcoll =
+ input.getPipeline().apply("CreateSingletonPcoll", Create.of(Arrays.asList(1)));
+
+ // For each (File, Offset) pair, calculate the number of lines occurring before the Range for
+ // each File
+
+ // After computing the number of lines before each range, we can find the line number in
+ // original file as numLiesBeforeOffset + lineNumInCurrentOffset
+ PCollectionView<Map<KV<String, Long>, Long>> numLinesBeforeEachRange =
+ singletonPcoll
+ .apply(
+ "ComputeLinesBeforeRange",
+ ParDo.of(new ComputeLinesBeforeEachRange(rangeSizes)).withSideInputs(rangeSizes))
+ .apply("NumLinesBeforeEachRangeAsView", View.asMap());
+
+ return linesGroupedByFileAndRange.apply(
+ "AssignLineNums",
+ ParDo.of(new AssignLineNums(numLinesBeforeEachRange))
+ .withSideInputs(numLinesBeforeEachRange));
+ }
+
+ @VisibleForTesting
+ static class AddFileNameAndRange
+ extends DoFn<RecordWithMetadata, KV<KV<String, Long>, RecordWithMetadata>> {
+ @ProcessElement
+ public void processElement(
+ @Element RecordWithMetadata line,
+ OutputReceiver<KV<KV<String, Long>, RecordWithMetadata>> out) {
+ out.output(KV.of(KV.of(line.getFileName(), line.getRange().getRangeNum()), line));
+ }
+ }
+
+ /**
+ * Helper class for computing number of lines in the File preceding the beginning of the Range
+ * in this file.
+ */
+ @VisibleForTesting
+ static class ComputeLinesBeforeEachRange extends DoFn<Integer, KV<KV<String, Long>, Long>> {
+ private final PCollectionView<Map<KV<String, Long>, Long>> rangeSizes;
+
+ public ComputeLinesBeforeEachRange(PCollectionView<Map<KV<String, Long>, Long>> rangeSizes) {
+ this.rangeSizes = rangeSizes;
+ }
+
+ // Add custom comparator as KV<K, V> is not comparable by default
+ private static class FileRangeComparator<K extends Comparable<K>, V extends Comparable<V>>
+ implements Comparator<KV<K, V>> {
+ @Override
+ public int compare(KV<K, V> a, KV<K, V> b) {
+ if (a.getKey().compareTo(b.getKey()) == 0) {
+ return a.getValue().compareTo(b.getValue());
+ }
+ return a.getKey().compareTo(b.getKey());
+ }
+ }
+
+ @ProcessElement
+ public void processElement(ProcessContext p) {
+ // Get the Map Containing the size from side-input
+ Map<KV<String, Long>, Long> rangeSizesMap = p.sideInput(rangeSizes);
+
+ // The FileRange Pair must be sorted
+ SortedMap<KV<String, Long>, Long> sorted = new TreeMap<>(new FileRangeComparator<>());
+
+ // Initialize sorted map with values
+ for (Map.Entry<KV<String, Long>, Long> entry : rangeSizesMap.entrySet()) {
+ sorted.put(entry.getKey(), entry.getValue());
+ }
+
+ // HashMap that tracks lines passed for each file
+ Map<String, Long> pastLines = new HashMap<>();
+
+ // For each (File, Range) Pair, compute the number of lines before it
+ for (Map.Entry entry : sorted.entrySet()) {
+ Long lines = (long) entry.getValue();
+ KV<String, Long> fileRange = (KV<String, Long>) entry.getKey();
+ String file = fileRange.getKey();
+ Long linesBefore = 0L;
+ if (pastLines.containsKey(file)) {
+ linesBefore = pastLines.get(file);
+ }
+ p.output(KV.of(fileRange, linesBefore));
+ pastLines.put(file, linesBefore + lines);
+ }
+ }
+ }
+
+ static class AssignLineNums
+ extends DoFn<KV<KV<String, Long>, RecordWithMetadata>, RecordWithMetadata> {
+ PCollectionView<Map<KV<String, Long>, Long>> numLinesBeforeEachRange;
+
+ public AssignLineNums(PCollectionView<Map<KV<String, Long>, Long>> numLinesBeforeEachRange) {
+ this.numLinesBeforeEachRange = numLinesBeforeEachRange;
+ }
+
+ @ProcessElement
+ public void processElement(ProcessContext p) {
+ Long range = p.element().getKey().getValue();
+ String file = p.element().getKey().getKey();
+ RecordWithMetadata line = p.element().getValue();
+ Long linesLessThanThisRange = p.sideInput(numLinesBeforeEachRange).get(KV.of(file, range));
+ RecordWithMetadata newLine =
+ RecordWithMetadata.newBuilder()
+ .setRecordValue(line.getRecordValue())
+ .setRecordNum(line.getRange().getRangeLineNum() + linesLessThanThisRange)
+ .setFileName(line.getFileName())
+ .setRange(line.getRange())
+ .build();
+ p.output(newLine);
+ }
+ }
+
+ // Helper to create a source specific to the requested compression type.
+ protected FileBasedSource<RecordWithMetadata> getSource() {
+ return CompressedSource.from(
+ new ContextualTextIOSource(
+ getFilepattern(),
+ getMatchConfiguration().getEmptyMatchTreatment(),
+ getDelimiter(),
+ getHasMultilineCSVRecords()))
+ .withCompression(getCompression());
+ }
+
+ @Override
+ public void populateDisplayData(DisplayData.Builder builder) {
+ super.populateDisplayData(builder);
+ builder
+ .add(
+ DisplayData.item("compressionType", getCompression().toString())
+ .withLabel("Compression Type"))
+ .addIfNotNull(DisplayData.item("filePattern", getFilepattern()).withLabel("File Pattern"))
+ .include("matchConfiguration", getMatchConfiguration())
+ .addIfNotNull(
+ DisplayData.item("delimiter", Arrays.toString(getDelimiter()))
+ .withLabel("Custom delimiter to split records"))
+ .addIfNotNull(
+ DisplayData.item("hasMultilineCSVRecords", getHasMultilineCSVRecords())
+ .withLabel("Has RFC4180 MultiLineCSV Records"));
+ }
+ }
+
+ /** Implementation of {@link #readFiles}. */
+ @AutoValue
+ public abstract static class ReadFiles
+ extends PTransform<PCollection<FileIO.ReadableFile>, PCollection<RecordWithMetadata>> {
+ abstract long getDesiredBundleSizeBytes();
+
+ @SuppressWarnings("mutable") // this returns an array that can be mutated by the caller
+ abstract byte @Nullable [] getDelimiter();
+
+ abstract boolean getHasMultilineCSVRecords();
+
+ abstract Builder toBuilder();
+
+ @AutoValue.Builder
+ abstract static class Builder {
+ abstract Builder setDesiredBundleSizeBytes(long desiredBundleSizeBytes);
+
+ abstract Builder setHasMultilineCSVRecords(boolean hasMultilineCSVRecords);
+
+ abstract Builder setDelimiter(byte @Nullable [] delimiter);
+
+ abstract ReadFiles build();
+ }
+
+ @VisibleForTesting
+ ReadFiles withDesiredBundleSizeBytes(long desiredBundleSizeBytes) {
+ return toBuilder().setDesiredBundleSizeBytes(desiredBundleSizeBytes).build();
+ }
+
+ /** Like {@link Read#withDelimiter}. */
+ public ReadFiles withDelimiter(byte[] delimiter) {
+ return toBuilder().setDelimiter(delimiter).build();
+ }
+
+ @Override
+ public PCollection<RecordWithMetadata> expand(PCollection<FileIO.ReadableFile> input) {
+ SchemaCoder<RecordWithMetadata> coder = null;
+ try {
+ coder = input.getPipeline().getSchemaRegistry().getSchemaCoder(RecordWithMetadata.class);
+ } catch (NoSuchSchemaException e) {
+ System.out.println("No Coder!");
Review comment:
Need to use LOGGER
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