org.apache.ignite.compute

Class ComputeJobAdapter

java.lang.Object

org.apache.ignite.compute.ComputeJobAdapter

All Implemented Interfaces:

Serializable, Callable<Object>, ComputeJob

Direct Known Subclasses:

ComputeJobContinuationAdapter

public abstract class ComputeJobAdapter
extends Object
implements ComputeJob, Callable<Object>

Convenience adapter for ComputeJob implementations. It provides the following functionality:

• Default implementation of ComputeJob.cancel() method and ability to check whether cancellation occurred with isCancelled() method.
• Ability to set and get job arguments via setArguments(Object...) and argument(int) methods.

See Also:

Serialized Form

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	ComputeJobAdapter() No-arg constructor.
protected	ComputeJobAdapter(Object... args) Creates job with specified arguments.
protected	ComputeJobAdapter(@Nullable Object arg) Creates job with one arguments.

Method Summary

Modifier and Type	Method and Description
<T> T	argument(int idx) Gets job argument.
protected @Nullable Object[]	arguments() Gets array of job arguments.
Object	call()
void	cancel() This method is called when system detects that completion of this job can no longer alter the overall outcome (for example, when parent task has already reduced the results).
protected boolean	isCancelled() This method tests whether or not this job was cancelled.
void	setArguments(Object... args) Sets given arguments.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.ignite.compute.ComputeJob

execute

Constructor Detail

ComputeJobAdapter

protected ComputeJobAdapter()

No-arg constructor.

ComputeJobAdapter

protected ComputeJobAdapter(@Nullable
                            @Nullable Object arg)

Creates job with one arguments. This constructor exists for better backward compatibility with internal Ignite 2.x code.

Parameters:

arg - Job argument.

ComputeJobAdapter

protected ComputeJobAdapter(@Nullable
                            Object... args)

Creates job with specified arguments.

Parameters:

args - Optional job arguments.

Method Detail

setArguments

public void setArguments(@Nullable
                         Object... args)

Sets given arguments.

Parameters:

args - Optional job arguments to set.

cancel

public void cancel()

This method is called when system detects that completion of this job can no longer alter the overall outcome (for example, when parent task has already reduced the results). Job is also cancelled when IgniteFuture.cancel() is called.

Note that job cancellation is only a hint, and just like with Thread.interrupt() method, it is really up to the actual job instance to gracefully finish execution and exit.

Specified by:

cancel in interface ComputeJob

isCancelled

protected final boolean isCancelled()

This method tests whether or not this job was cancelled. This method is thread-safe and can be called without extra synchronization.

This method can be periodically called in ComputeJob.execute() method implementation to check whether or not this job cancelled. Note that system calls cancel() method only as a hint and this is a responsibility of the implementation of the job to properly cancel its execution.

Returns:

true if this job was cancelled, false otherwise.

argument

@Nullable
public <T> T argument(int idx)

Gets job argument.

Type Parameters:

T - Type of the argument to return.

Parameters:

idx - Index of the argument.

Returns:

Job argument.

Throws:

NullPointerException - Thrown in case when there no arguments set.

IllegalArgumentException - Thrown if index is invalid.

arguments

@Nullable
protected @Nullable Object[] arguments()

Gets array of job arguments. Note that changes to this array may affect job execution.

Returns:

Array of job arguments.

call

public final Object call()

Specified by:

call in interface Callable<Object>