org.apache.parquet.hadoop.api

Class DelegatingReadSupport<T>

java.lang.Object

org.apache.parquet.hadoop.api.ReadSupport<T>

org.apache.parquet.hadoop.api.DelegatingReadSupport<T>

Type Parameters:

T -

public class DelegatingReadSupport<T>
extends ReadSupport<T>

Helps composing read supports

Author:

Julien Le Dem

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.parquet.hadoop.api.ReadSupport

ReadSupport.ReadContext

Field Summary

Fields inherited from class org.apache.parquet.hadoop.api.ReadSupport

PARQUET_READ_SCHEMA

Constructor Summary

Constructors

Constructor and Description
DelegatingReadSupport(ReadSupport<T> delegate)

Method Summary

Methods

Modifier and Type	Method and Description
ReadSupport.ReadContext	init(InitContext context) called in InputFormat.getSplits(org.apache.hadoop.mapreduce.JobContext) in the front end
RecordMaterializer<T>	prepareForRead(org.apache.hadoop.conf.Configuration configuration, Map<String,String> keyValueMetaData, MessageType fileSchema, ReadSupport.ReadContext readContext) called in RecordReader.initialize(org.apache.hadoop.mapreduce.InputSplit, org.apache.hadoop.mapreduce.TaskAttemptContext) in the back end the returned RecordMaterializer will materialize the records and add them to the destination
String	toString()

Methods inherited from class org.apache.parquet.hadoop.api.ReadSupport

getSchemaForRead, getSchemaForRead, init

Methods inherited from class java.lang.Object

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

Constructor Detail

DelegatingReadSupport

public DelegatingReadSupport(ReadSupport<T> delegate)

Method Detail

init

public ReadSupport.ReadContext init(InitContext context)

Description copied from class: ReadSupport

called in InputFormat.getSplits(org.apache.hadoop.mapreduce.JobContext) in the front end

Overrides:

init in class ReadSupport<T>

Parameters:

context - the initialisation context

Returns:

the readContext that defines how to read the file

prepareForRead

public RecordMaterializer<T> prepareForRead(org.apache.hadoop.conf.Configuration configuration,
                                   Map<String,String> keyValueMetaData,
                                   MessageType fileSchema,
                                   ReadSupport.ReadContext readContext)

Description copied from class: ReadSupport

called in RecordReader.initialize(org.apache.hadoop.mapreduce.InputSplit, org.apache.hadoop.mapreduce.TaskAttemptContext) in the back end the returned RecordMaterializer will materialize the records and add them to the destination

Specified by:

prepareForRead in class ReadSupport<T>

Parameters:

configuration - the job configuration

keyValueMetaData - the app specific metadata from the file

fileSchema - the schema of the file

readContext - returned by the init method

Returns:

the recordMaterializer that will materialize the records

toString

public String toString()

Overrides:

toString in class Object