org.infinispan.commands.read
Class MapReduceCommand

java.lang.Object
  org.infinispan.commands.remote.BaseRpcCommand
      org.infinispan.commands.read.MapReduceCommand

All Implemented Interfaces:

CacheRpcCommand, ReplicableCommand

public class MapReduceCommand
extends BaseRpcCommand

MapReduceCommand is used to migrate Mapper and Reducer to remote JVM where they will get invoked.

Since:

5.0

Author:

Vladimir Blagojevic

Field Summary

static int	COMMAND_ID
protected DistributionManager	dm
protected InvocationContextContainer	icc
protected Set<Object>	keys
protected Address	localAddress

Fields inherited from class org.infinispan.commands.remote.BaseRpcCommand

cacheName

Constructor Summary

MapReduceCommand(Mapper m, Reducer r, String cacheName, Collection<Object> inputKeys)

MapReduceCommand(Mapper m, Reducer r, String cacheName, Object... inputKeys)

MapReduceCommand(String cacheName)

Method Summary

boolean	equals(Object o)
byte	getCommandId() Used by marshallers to convert this command into an id for streaming.
Object[]	getParameters() Used by marshallers to stream this command across a network
int	hashCode()
void	init(CommandsFactory factory, InterceptorChain invoker, InvocationContextContainer icc, DistributionManager dm, Address localAddress)
boolean	isReturnValueExpected() If true, a return value will be provided when performed remotely.
Object	perform(InvocationContext context) Performs invocation of mapping phase and local reduce phase before returning result to master node
void	setParameters(int commandId, Object[] args) Used by the CommandsFactory to create a command from raw data read off a stream.
String	toString()

Methods inherited from class org.infinispan.commands.remote.BaseRpcCommand

getCacheName, getOrigin, setOrigin

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

COMMAND_ID

public static final int COMMAND_ID

See Also:

Constant Field Values

keys

protected Set<Object> keys

icc

protected InvocationContextContainer icc

dm

protected DistributionManager dm

localAddress

protected Address localAddress

Constructor Detail

MapReduceCommand

public MapReduceCommand(String cacheName)

MapReduceCommand

public MapReduceCommand(Mapper m,
                        Reducer r,
                        String cacheName,
                        Object... inputKeys)

MapReduceCommand

public MapReduceCommand(Mapper m,
                        Reducer r,
                        String cacheName,
                        Collection<Object> inputKeys)

Method Detail

init

public void init(CommandsFactory factory,
                 InterceptorChain invoker,
                 InvocationContextContainer icc,
                 DistributionManager dm,
                 Address localAddress)

perform

public Object perform(InvocationContext context)
               throws Throwable

Performs invocation of mapping phase and local reduce phase before returning result to master node

Parameters:

context - invocation context

Returns:

Map of intermediate key value pairs

Throws:

Throwable - in the event of problems.

getCommandId

public byte getCommandId()

Description copied from interface: ReplicableCommand

Used by marshallers to convert this command into an id for streaming.

Returns:

the method id of this command. This is compatible with pre-2.2.0 MethodCall ids.

getParameters

public Object[] getParameters()

Description copied from interface: ReplicableCommand

Used by marshallers to stream this command across a network

Returns:

an object array of arguments, compatible with pre-2.2.0 MethodCall args.

setParameters

public void setParameters(int commandId,
                          Object[] args)

Description copied from interface: ReplicableCommand

Used by the CommandsFactory to create a command from raw data read off a stream.

Parameters:

commandId - command id to set. This is usually unused but *could* be used in the event of a command having multiple IDs, such as PutKeyValueCommand.

args - object array of args

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class BaseRpcCommand

isReturnValueExpected

public boolean isReturnValueExpected()

Description copied from interface: ReplicableCommand

If true, a return value will be provided when performed remotely. Otherwise, a remote ResponseGenerator may choose to simply return null to save on marshalling costs.

Returns:

true or false