org.apache.beam.sdk.io

Class TextIO.Read

java.lang.Object

org.apache.beam.sdk.transforms.PTransform<PBegin,PCollection<java.lang.String>>

org.apache.beam.sdk.io.TextIO.Read

All Implemented Interfaces:

java.io.Serializable, HasDisplayData

Enclosing class:

TextIO

public abstract static class TextIO.Read
extends PTransform<PBegin,PCollection<java.lang.String>>

Implementation of TextIO.read().

See Also:

Serialized Form

Field Summary

Fields inherited from class org.apache.beam.sdk.transforms.PTransform

name

Constructor Summary

Constructors

Constructor and Description
Read()

Method Summary

Modifier and Type	Method and Description
PCollection<java.lang.String>	expand(PBegin input) Override this method to specify how this PTransform should be expanded on the given InputT.
TextIO.Read	from(java.lang.String filepattern) Reads text files that reads from the file(s) with the given filename or filename pattern.
TextIO.Read	from(ValueProvider<java.lang.String> filepattern) Same as from(filepattern), but accepting a ValueProvider.
protected FileBasedSource<java.lang.String>	getSource()
void	populateDisplayData(DisplayData.Builder builder) Register display data for the given transform or component.
TextIO.Read	watchForNewFiles(Duration pollInterval, Watch.Growth.TerminationCondition<java.lang.String,?> terminationCondition) See FileIO.MatchConfiguration.continuously(org.joda.time.Duration, org.apache.beam.sdk.transforms.Watch.Growth.TerminationCondition<java.lang.String, ?>).
TextIO.Read	withCompression(Compression compression) Reads from input sources using the specified compression type.
TextIO.Read	withCompressionType(TextIO.CompressionType compressionType) Deprecated. Use withCompression(org.apache.beam.sdk.io.Compression).
TextIO.Read	withDelimiter(byte[] delimiter) Set the custom delimiter to be used in place of the default ones ('\r', '\n' or '\r\n').
TextIO.Read	withEmptyMatchTreatment(EmptyMatchTreatment treatment) See FileIO.MatchConfiguration.withEmptyMatchTreatment(org.apache.beam.sdk.io.fs.EmptyMatchTreatment).
TextIO.Read	withHintMatchesManyFiles() Hints that the filepattern specified in from(String) matches a very large number of files.
TextIO.Read	withMatchConfiguration(FileIO.MatchConfiguration matchConfiguration) Sets the FileIO.MatchConfiguration.

Methods inherited from class org.apache.beam.sdk.transforms.PTransform

getAdditionalInputs, getDefaultOutputCoder, getDefaultOutputCoder, getDefaultOutputCoder, getKindString, getName, toString, validate

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

Read

public Read()

Method Detail

from

public TextIO.Read from(java.lang.String filepattern)

Reads text files that reads from the file(s) with the given filename or filename pattern.

This can be a local path (if running locally), or a Google Cloud Storage filename or filename pattern of the form "gs://<bucket>/<filepath>" (if running locally or using remote execution service).

Standard Java Filesystem glob patterns ("*", "?", "[..]") are supported.

If it is known that the filepattern will match a very large number of files (at least tens of thousands), use withHintMatchesManyFiles() for better performance and scalability.

from

public TextIO.Read from(ValueProvider<java.lang.String> filepattern)

Same as from(filepattern), but accepting a ValueProvider.

withMatchConfiguration

public TextIO.Read withMatchConfiguration(FileIO.MatchConfiguration matchConfiguration)

Sets the FileIO.MatchConfiguration.

withCompressionType

@Deprecated
public TextIO.Read withCompressionType(TextIO.CompressionType compressionType)

Deprecated. Use withCompression(org.apache.beam.sdk.io.Compression).

withCompression

public TextIO.Read withCompression(Compression compression)

Reads from input sources using the specified compression type.

If no compression type is specified, the default is Compression.AUTO.

watchForNewFiles

@Experimental(value=SPLITTABLE_DO_FN)
public TextIO.Read watchForNewFiles(Duration pollInterval,
                                                                          Watch.Growth.TerminationCondition<java.lang.String,?> terminationCondition)

See FileIO.MatchConfiguration.continuously(org.joda.time.Duration, org.apache.beam.sdk.transforms.Watch.Growth.TerminationCondition<java.lang.String, ?>).

This works only in runners supporting Experimental.Kind.SPLITTABLE_DO_FN.

withHintMatchesManyFiles

public TextIO.Read withHintMatchesManyFiles()

Hints that the filepattern specified in from(String) matches a very large number of files.

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).

withEmptyMatchTreatment

public TextIO.Read withEmptyMatchTreatment(EmptyMatchTreatment treatment)

See FileIO.MatchConfiguration.withEmptyMatchTreatment(org.apache.beam.sdk.io.fs.EmptyMatchTreatment).

withDelimiter

public TextIO.Read withDelimiter(byte[] delimiter)

Set the custom delimiter to be used in place of the default ones ('\r', '\n' or '\r\n').

expand

public PCollection<java.lang.String> expand(PBegin input)

Description copied from class: PTransform

Override this method to specify how this PTransform should be expanded on the given InputT.

NOTE: This method should not be called directly. Instead apply the PTransform should be applied to the InputT using the apply method.

Composite transforms, which are defined in terms of other transforms, should return the output of one of the composed transforms. Non-composite transforms, which do not apply any transforms internally, should return a new unbound output and register evaluators (via backend-specific registration methods).

Specified by:

expand in class PTransform<PBegin,PCollection<java.lang.String>>

getSource

protected FileBasedSource<java.lang.String> getSource()

populateDisplayData

public void populateDisplayData(DisplayData.Builder builder)

Description copied from class: PTransform

Register display data for the given transform or component.

populateDisplayData(DisplayData.Builder) is invoked by Pipeline runners to collect display data via DisplayData.from(HasDisplayData). Implementations may call super.populateDisplayData(builder) in order to register display data in the current namespace, but should otherwise use subcomponent.populateDisplayData(builder) to use the namespace of the subcomponent.

By default, does not register any display data. Implementors may override this method to provide their own display data.

Specified by:

populateDisplayData in interface HasDisplayData

Overrides:

populateDisplayData in class PTransform<PBegin,PCollection<java.lang.String>>

Parameters:

builder - The builder to populate with display data.

See Also:

HasDisplayData