org.infinispan.commands.read

Class DistributedExecuteCommand<V>

java.lang.Object

org.infinispan.commands.remote.BaseRpcCommand

org.infinispan.commands.read.DistributedExecuteCommand<V>

All Implemented Interfaces:

CancellableCommand, CacheRpcCommand, ReplicableCommand, VisitableCommand

public class DistributedExecuteCommand<V>
extends BaseRpcCommand
implements VisitableCommand, CancellableCommand

DistributedExecuteCommand is used to migrate Callable and execute it in remote JVM.

Since:

5.0

Author:

Vladimir Blagojevic, Mircea Markus

Field Summary

Fields

Modifier and Type	Field and Description
static int	COMMAND_ID

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

cacheName

Constructor Summary

Constructors

Constructor and Description
DistributedExecuteCommand()
DistributedExecuteCommand(String cacheName)
DistributedExecuteCommand(String cacheName, Collection<Object> inputKeys, Callable<V> callable)

Method Summary

Modifier and Type	Method and Description
Object	acceptVisitor(InvocationContext ctx, Visitor visitor) Accept a visitor, and return the result of accepting this visitor.
boolean	canBlock() If true, the command is processed asynchronously in a thread provided by an Infinispan thread pool.
boolean	equals(Object obj)
Callable<V>	getCallable()
byte	getCommandId() Used by marshallers to convert this command into an id for streaming.
Set<Object>	getKeys()
UUID	getUUID() Returns UUID of a command
int	hashCode()
boolean	hasKeys()
boolean	ignoreCommandOnStatus(ComponentStatus status) Similar to VisitableCommand.shouldInvoke(InvocationContext) but evaluated by InvocationContextInterceptor.
void	init(Cache<Object,Object> cache)
boolean	isReturnValueExpected() If true, a return value will be provided when performed remotely.
V	perform(InvocationContext context) Performs invocation of Callable and returns result
void	readFrom(ObjectInput input) Reads this instance from the stream written by ReplicableCommand.writeTo(ObjectOutput).
boolean	readsExistingValues()
boolean	shouldInvoke(InvocationContext ctx) Used by the InboundInvocationHandler to determine whether the command should be invoked or not.
String	toString()
void	writeTo(ObjectOutput output) Writes this instance to the ObjectOutput.

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

Methods inherited from interface org.infinispan.commands.VisitableCommand

alwaysReadsExistingValues

Methods inherited from interface org.infinispan.commands.remote.CacheRpcCommand

getCacheName, getOrigin, setOrigin

Methods inherited from interface org.infinispan.commands.ReplicableCommand

getParameters, setParameters

Field Detail

COMMAND_ID

public static final int COMMAND_ID

See Also:

Constant Field Values

Constructor Detail

DistributedExecuteCommand

public DistributedExecuteCommand(String cacheName)

DistributedExecuteCommand

public DistributedExecuteCommand(String cacheName,
                                 Collection<Object> inputKeys,
                                 Callable<V> callable)

DistributedExecuteCommand

public DistributedExecuteCommand()

Method Detail

init

public void init(Cache<Object,Object> cache)

acceptVisitor

public Object acceptVisitor(InvocationContext ctx,
                            Visitor visitor)
                     throws Throwable

Description copied from interface: VisitableCommand

Accept a visitor, and return the result of accepting this visitor.

Specified by:

acceptVisitor in interface VisitableCommand

Parameters:

ctx - invocation context

visitor - visitor to accept

Returns:

arbitrary return value

Throws:

Throwable - in the event of problems

ignoreCommandOnStatus

public boolean ignoreCommandOnStatus(ComponentStatus status)

Description copied from interface: VisitableCommand

Similar to VisitableCommand.shouldInvoke(InvocationContext) but evaluated by InvocationContextInterceptor. Commands can opt to be discarded in case the cache status is not suited (as InvalidateCommand)

Specified by:

ignoreCommandOnStatus in interface VisitableCommand

Returns:

true if the command should NOT be invoked.

readsExistingValues

public boolean readsExistingValues()

Specified by:

readsExistingValues in interface VisitableCommand

Returns:

true if the command needs to read the previous values of the keys it acts on.

shouldInvoke

public boolean shouldInvoke(InvocationContext ctx)

Description copied from interface: VisitableCommand

Used by the InboundInvocationHandler to determine whether the command should be invoked or not.

Specified by:

shouldInvoke in interface VisitableCommand

Returns:

true if the command should be invoked, false otherwise.

perform

public V perform(InvocationContext context)
          throws Exception

Performs invocation of Callable and returns result

Specified by:

perform in interface ReplicableCommand

Parameters:

context - invocation context

Returns:

result of Callable invocations

Throws:

Exception

getCallable

public Callable<V> getCallable()

getKeys

public Set<Object> getKeys()

hasKeys

public boolean hasKeys()

getCommandId

public byte getCommandId()

Description copied from interface: ReplicableCommand

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

Specified by:

getCommandId in interface ReplicableCommand

Returns:

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

getUUID

public UUID getUUID()

Description copied from interface: CancellableCommand

Returns UUID of a command

Specified by:

getUUID in interface CancellableCommand

Returns:

command UUID

writeTo

public void writeTo(ObjectOutput output)
             throws IOException

Description copied from interface: ReplicableCommand

Writes this instance to the ObjectOutput.

Specified by:

writeTo in interface ReplicableCommand

Parameters:

output - the stream.

Throws:

IOException - if an error occurred during the I/O.

readFrom

public void readFrom(ObjectInput input)
              throws IOException,
                     ClassNotFoundException

Description copied from interface: ReplicableCommand

Reads this instance from the stream written by ReplicableCommand.writeTo(ObjectOutput).

Specified by:

readFrom in interface ReplicableCommand

Parameters:

input - the stream to read.

Throws:

IOException - if an error occurred during the I/O.

ClassNotFoundException - if it tries to load an undefined class.

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Overrides:

equals 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.

Specified by:

isReturnValueExpected in interface ReplicableCommand

Returns:

true or false

canBlock

public boolean canBlock()

Description copied from interface: ReplicableCommand

If true, the command is processed asynchronously in a thread provided by an Infinispan thread pool. Otherwise, the command is processed directly in the JGroups thread.

This feature allows to avoid keep a JGroups thread busy that can originate discard of messages and retransmissions. So, the commands that can block (waiting for some state, acquiring locks, etc.) should return true.

Specified by:

canBlock in interface ReplicableCommand

Overrides:

canBlock in class BaseRpcCommand

Returns:

true if the command can block/wait, false otherwise