org.apache.hive.hcatalog.data.transfer

Class DataTransferFactory

java.lang.Object

org.apache.hive.hcatalog.data.transfer.DataTransferFactory

public class DataTransferFactory
extends Object

Use this factory to get instances of HCatReader or HCatWriter at master and slave nodes.

Constructor Summary

Constructors

Constructor and Description
DataTransferFactory()

Method Summary

Methods

Modifier and Type	Method and Description
static HCatReader	getHCatReader(ReadEntity re, Map<String,String> config) This should be called once from master node to obtain an instance of HCatReader.
static HCatReader	getHCatReader(ReaderContext context, int slaveNumber) This should only be called once from every slave node to obtain an instance of HCatReader.
static HCatReader	getHCatReader(ReaderContext context, int slaveNumber, StateProvider sp) This should only be called once from every slave node to obtain an instance of HCatReader.
static HCatWriter	getHCatWriter(WriteEntity we, Map<String,String> config) This should be called at master node to obtain an instance of HCatWriter.
static HCatWriter	getHCatWriter(WriterContext cntxt) This should be called at slave nodes to obtain an instance of HCatWriter.
static HCatWriter	getHCatWriter(WriterContext cntxt, StateProvider sp) This should be called at slave nodes to obtain an instance of HCatWriter.

Methods inherited from class java.lang.Object

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

Constructor Detail

DataTransferFactory

public DataTransferFactory()

Method Detail

getHCatReader

public static HCatReader getHCatReader(ReadEntity re,
                       Map<String,String> config)

This should be called once from master node to obtain an instance of HCatReader.

Parameters:

re - ReadEntity built using ReadEntity.Builder

config - any configuration which master node wants to pass to HCatalog

Returns:

HCatReader

getHCatReader

public static HCatReader getHCatReader(ReaderContext context,
                       int slaveNumber)

This should only be called once from every slave node to obtain an instance of HCatReader.

Parameters:

context - reader context obtained at the master node

slaveNumber - which slave this is, determines which part of the read is done

Returns:

HCatReader

getHCatReader

public static HCatReader getHCatReader(ReaderContext context,
                       int slaveNumber,
                       StateProvider sp)

This should only be called once from every slave node to obtain an instance of HCatReader. This should be called if an external system has some state to provide to HCatalog.

Parameters:

context - reader context obtained at the master node

slaveNumber - which slave this is, determines which part of the read is done

sp - StateProvider

Returns:

HCatReader

getHCatWriter

public static HCatWriter getHCatWriter(WriteEntity we,
                       Map<String,String> config)

This should be called at master node to obtain an instance of HCatWriter.

Parameters:

we - WriteEntity built using WriteEntity.Builder

config - any configuration which master wants to pass to HCatalog

Returns:

HCatWriter

getHCatWriter

public static HCatWriter getHCatWriter(WriterContext cntxt)

This should be called at slave nodes to obtain an instance of HCatWriter.

Parameters:

cntxt - WriterContext obtained at master node

Returns:

HCatWriter

getHCatWriter

public static HCatWriter getHCatWriter(WriterContext cntxt,
                       StateProvider sp)

This should be called at slave nodes to obtain an instance of HCatWriter. If an external system has some mechanism for providing state to HCatalog, this constructor can be used.

Parameters:

cntxt - WriterContext obtained at master node

sp - StateProvider

Returns:

HCatWriter