Package org.apache.beam.sdk.io

Enum Class Compression

java.lang.Object

java.lang.Enum<Compression>

org.apache.beam.sdk.io.Compression

All Implemented Interfaces:

Serializable, Comparable<Compression>, Constable

public enum Compression
extends Enum<Compression>

Various compression types for reading/writing files.

Nested Class Summary

Nested classes/interfaces inherited from class java.lang.Enum

Enum.EnumDesc<E extends Enum<E>>

Enum Constant Summary

Enum Constants

Enum Constant	Description
AUTO	When reading a file, automatically determine the compression type based on filename extension.
BZIP2	BZip compression.
DEFLATE	Deflate compression.
GZIP	GZip compression.
LZO	LZO compression using LZO codec.
LZOP	LZOP compression using LZOP codec.
SNAPPY	Google Snappy compression.
UNCOMPRESSED	No compression.
ZIP	Zip compression.
ZSTD	ZStandard compression.

Method Summary

Modifier and Type	Method	Description
static Compression	detect(String filename)
String	getSuggestedSuffix()
boolean	isCompressed(String filename)
boolean	matches(String filename)
abstract ReadableByteChannel	readDecompressed(ReadableByteChannel channel)
static Compression	valueOf(String name)	Returns the enum constant of this class with the specified name.
static Compression[]	values()	Returns an array containing the constants of this enum class, in the order they are declared.
abstract WritableByteChannel	writeCompressed(WritableByteChannel channel)

Methods inherited from class java.lang.Enum

clone, compareTo, describeConstable, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Details

AUTO

public static final Compression AUTO

When reading a file, automatically determine the compression type based on filename extension. Not applicable when writing files.

UNCOMPRESSED

public static final Compression UNCOMPRESSED

No compression.

GZIP

public static final Compression GZIP

GZip compression.

BZIP2

public static final Compression BZIP2

BZip compression.

ZIP

public static final Compression ZIP

Zip compression.

ZSTD

public static final Compression ZSTD

ZStandard compression.

The .zst extension is specified in RFC 8478.

The Beam Java SDK does not pull in the Zstd library by default, so it is the user's responsibility to declare an explicit dependency on zstd-jni. Attempts to read or write .zst files without zstd-jni loaded will result in NoClassDefFoundError at runtime.

LZO

public static final Compression LZO

LZO compression using LZO codec. .lzo_deflate extension is specified for files which use the LZO algorithm without headers.

The Beam Java SDK does not pull in the required libraries for LZO compression by default, so it is the user's responsibility to declare an explicit dependency on io.airlift:aircompressor and com.facebook.presto.hadoop:hadoop-apache2. Attempts to read or write .lzo_deflate files without io.airlift:aircompressor and com.facebook.presto.hadoop:hadoop-apache2 loaded will result in a NoClassDefFoundError at runtime.

LZOP

public static final Compression LZOP

LZOP compression using LZOP codec. .lzo extension is specified for files with magic bytes and headers.

Warning: The LZOP codec being used does not support concatenated LZOP streams and will silently ignore data after the end of the first LZOP stream.

The Beam Java SDK does not pull in the required libraries for LZOP compression by default, so it is the user's responsibility to declare an explicit dependency on io.airlift:aircompressor and com.facebook.presto.hadoop:hadoop-apache2. Attempts to read or write .lzo files without io.airlift:aircompressor and com.facebook.presto.hadoop:hadoop-apache2 loaded will result in a NoClassDefFoundError at runtime.

DEFLATE

public static final Compression DEFLATE

Deflate compression.

SNAPPY

public static final Compression SNAPPY

Google Snappy compression.

Method Details

values

public static Compression[] values()

Returns an array containing the constants of this enum class, in the order they are declared.

Returns:

an array containing the constants of this enum class, in the order they are declared

valueOf

public static Compression valueOf(String name)

Returns the enum constant of this class with the specified name. The string must match exactly an identifier used to declare an enum constant in this class. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum class has no constant with the specified name

NullPointerException - if the argument is null

getSuggestedSuffix

public String getSuggestedSuffix()

matches

public boolean matches(String filename)

isCompressed

public boolean isCompressed(String filename)

detect

public static Compression detect(String filename)

readDecompressed

public abstract ReadableByteChannel readDecompressed(ReadableByteChannel channel)
                                              throws IOException

Throws:

IOException

writeCompressed

public abstract WritableByteChannel writeCompressed(WritableByteChannel channel)
                                             throws IOException

Throws:

IOException