Package org.apache.hadoop.io.erasurecode

Class CodecUtil

java.lang.Object

org.apache.hadoop.io.erasurecode.CodecUtil

@Private
public final class CodecUtil
extends java.lang.Object

A codec & coder utility to help create coders conveniently. CodecUtil includes erasure coder configurations key and default values such as coder class name and erasure codec option values included by ErasureCodecOptions. ErasureEncoder and ErasureDecoder are created by createEncoder and createDecoder respectively.RawErasureEncoder and RawErasureDecoder are are created by createRawEncoder and createRawDecoder.

Field Summary

Fields

Modifier and Type	Field	Description
static java.lang.String	IO_ERASURECODE_CODEC
static java.lang.String	IO_ERASURECODE_CODEC_HHXOR
static java.lang.String	IO_ERASURECODE_CODEC_HHXOR_KEY	Erasure coder hitch hiker XOR codec.
static boolean	IO_ERASURECODE_CODEC_NATIVE_ENABLED_DEFAULT
static java.lang.String	IO_ERASURECODE_CODEC_NATIVE_ENABLED_KEY
static java.lang.String	IO_ERASURECODE_CODEC_RS
static java.lang.String	IO_ERASURECODE_CODEC_RS_KEY	Erasure coder Reed-Solomon codec.
static java.lang.String	IO_ERASURECODE_CODEC_RS_LEGACY_RAWCODERS_KEY	Comma separated raw codec name.
static java.lang.String	IO_ERASURECODE_CODEC_RS_RAWCODERS_KEY
static java.lang.String	IO_ERASURECODE_CODEC_XOR
static java.lang.String	IO_ERASURECODE_CODEC_XOR_KEY	Erasure coder XOR codec.
static java.lang.String	IO_ERASURECODE_CODEC_XOR_RAWCODERS_KEY	Raw coder factory for the XOR codec.

Method Summary

Modifier and Type	Method	Description
static ErasureDecoder	createDecoder(Configuration conf, ErasureCodecOptions options)	Create decoder corresponding to given codec.
static ErasureEncoder	createEncoder(Configuration conf, ErasureCodecOptions options)	Create encoder corresponding to given codec.
static RawErasureDecoder	createRawDecoder(Configuration conf, java.lang.String codec, ErasureCoderOptions coderOptions)	Create RS raw decoder according to configuration.
static RawErasureEncoder	createRawEncoder(Configuration conf, java.lang.String codec, ErasureCoderOptions coderOptions)	Create RS raw encoder according to configuration.
static boolean	hasCodec(java.lang.String codecName)

Methods inherited from class java.lang.Object

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

Field Detail

IO_ERASURECODE_CODEC

public static final java.lang.String IO_ERASURECODE_CODEC

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Constant Field Values

IO_ERASURECODE_CODEC_XOR_KEY

public static final java.lang.String IO_ERASURECODE_CODEC_XOR_KEY

Erasure coder XOR codec.

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Constant Field Values

IO_ERASURECODE_CODEC_XOR

public static final java.lang.String IO_ERASURECODE_CODEC_XOR

IO_ERASURECODE_CODEC_RS_KEY

public static final java.lang.String IO_ERASURECODE_CODEC_RS_KEY

Erasure coder Reed-Solomon codec.

See Also:

Constant Field Values

IO_ERASURECODE_CODEC_RS

public static final java.lang.String IO_ERASURECODE_CODEC_RS

IO_ERASURECODE_CODEC_HHXOR_KEY

public static final java.lang.String IO_ERASURECODE_CODEC_HHXOR_KEY

Erasure coder hitch hiker XOR codec.

See Also:

Constant Field Values

IO_ERASURECODE_CODEC_HHXOR

public static final java.lang.String IO_ERASURECODE_CODEC_HHXOR

IO_ERASURECODE_CODEC_RS_LEGACY_RAWCODERS_KEY

public static final java.lang.String IO_ERASURECODE_CODEC_RS_LEGACY_RAWCODERS_KEY

Comma separated raw codec name. The first coder is prior to the latter.

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Constant Field Values

IO_ERASURECODE_CODEC_RS_RAWCODERS_KEY

public static final java.lang.String IO_ERASURECODE_CODEC_RS_RAWCODERS_KEY

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Constant Field Values

IO_ERASURECODE_CODEC_XOR_RAWCODERS_KEY

public static final java.lang.String IO_ERASURECODE_CODEC_XOR_RAWCODERS_KEY

Raw coder factory for the XOR codec.

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Constant Field Values

IO_ERASURECODE_CODEC_NATIVE_ENABLED_KEY

public static final java.lang.String IO_ERASURECODE_CODEC_NATIVE_ENABLED_KEY

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Constant Field Values

IO_ERASURECODE_CODEC_NATIVE_ENABLED_DEFAULT

public static final boolean IO_ERASURECODE_CODEC_NATIVE_ENABLED_DEFAULT

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Constant Field Values

Method Detail

createEncoder

public static ErasureEncoder createEncoder(Configuration conf,
                                           ErasureCodecOptions options)

Create encoder corresponding to given codec.

Parameters:

options - Erasure codec options

conf - configuration.

Returns:

erasure encoder

createDecoder

public static ErasureDecoder createDecoder(Configuration conf,
                                           ErasureCodecOptions options)

Create decoder corresponding to given codec.

Parameters:

options - Erasure codec options

conf - configuration.

Returns:

erasure decoder

createRawEncoder

public static RawErasureEncoder createRawEncoder(Configuration conf,
                                                 java.lang.String codec,
                                                 ErasureCoderOptions coderOptions)

Create RS raw encoder according to configuration.

Parameters:

conf - configuration

coderOptions - coder options that's used to create the coder

codec - the codec to use. If null, will use the default codec

Returns:

raw encoder

createRawDecoder

public static RawErasureDecoder createRawDecoder(Configuration conf,
                                                 java.lang.String codec,
                                                 ErasureCoderOptions coderOptions)

Create RS raw decoder according to configuration.

Parameters:

conf - configuration

coderOptions - coder options that's used to create the coder

codec - the codec to use. If null, will use the default codec

Returns:

raw decoder

hasCodec

public static boolean hasCodec(java.lang.String codecName)