org.apache.beam.sdk.io

Enum Compression

java.lang.Object

java.lang.Enum<Compression>

org.apache.beam.sdk.io.Compression

All Implemented Interfaces:

java.io.Serializable, java.lang.Comparable<Compression>

public enum Compression
extends java.lang.Enum<Compression>

Various compression types for reading/writing files.

Enum Constant Summary

Enum Constants

Enum Constant and 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.
UNCOMPRESSED No compression.
ZIP Zip compression.
ZSTD ZStandard compression.

Method Summary

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

Methods inherited from class java.lang.Enum

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

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

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.

Method Detail

values

public static Compression[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (Compression c : Compression.values())
    System.out.println(c);

Returns:

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

valueOf

public static Compression valueOf(java.lang.String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (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:

java.lang.IllegalArgumentException - if this enum type has no constant with the specified name

java.lang.NullPointerException - if the argument is null

getSuggestedSuffix

public java.lang.String getSuggestedSuffix()

matches

public boolean matches(java.lang.String filename)

isCompressed

public boolean isCompressed(java.lang.String filename)

detect

public static Compression detect(java.lang.String filename)

readDecompressed

public abstract java.nio.channels.ReadableByteChannel readDecompressed(java.nio.channels.ReadableByteChannel channel)
                                                                throws java.io.IOException

Throws:

java.io.IOException

writeCompressed

public abstract java.nio.channels.WritableByteChannel writeCompressed(java.nio.channels.WritableByteChannel channel)
                                                               throws java.io.IOException

Throws:

java.io.IOException