io.crate.operation

Class RowCountResultRowDownstream

java.lang.Object

io.crate.operation.RowCountResultRowDownstream

All Implemented Interfaces:

RowReceiver

public class RowCountResultRowDownstream
extends java.lang.Object
implements RowReceiver

RowDownstream that will set a TaskResultFuture once the result is ready. It will also close the associated context once it is done

Constructor Summary

Constructors

Constructor and Description
RowCountResultRowDownstream(com.google.common.util.concurrent.SettableFuture<TaskResult> result)

Method Summary

Modifier and Type	Method and Description
void	fail(java.lang.Throwable throwable) Is called from the upstream in case of a failure.
void	finish() Called from the upstream to indicate that all rows are sent.
void	kill(java.lang.Throwable throwable) kill a RowReceiver to stop it's execution.
void	prepare() prepares / starts the RowReceiver, after this call it must be ready to receive rows
java.util.Set<Requirement>	requirements() specifies which requirements a downstream requires from an upstream in order to work correctly.
boolean	setNextRow(Row row) Feed the downstream with the next input row.
void	setUpstream(RowUpstream rowUpstream) an RowUpstream who wants to call RowReceiver.setNextRow(Row) calls setUpstream before he starts sending rows so that the RowReceiver can call pause/resume on the upstream.

Methods inherited from class java.lang.Object

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

Constructor Detail

RowCountResultRowDownstream

public RowCountResultRowDownstream(com.google.common.util.concurrent.SettableFuture<TaskResult> result)

Method Detail

setNextRow

public boolean setNextRow(Row row)

Description copied from interface: RowReceiver

Feed the downstream with the next input row. If the downstream does not need any more rows, it returns false, true otherwise. Any upstream who calls this methods must call RowReceiver.setUpstream(RowUpstream) exactly once so that the receiver is able to call pause/resume on its upstream. RowReceiver.finish() and RowReceiver.fail(Throwable) may be called without calling setUpstream if there are no rows.

Specified by:

setNextRow in interface RowReceiver

Parameters:

row - the next row - the row is usually a shared object and the instances content change after the setNextRow call.

Returns:

false if the downstream does not need any more rows, true otherwise.

finish

public void finish()

Description copied from interface: RowReceiver

Called from the upstream to indicate that all rows are sent. NOTE: This method must not throw any exceptions!

Specified by:

finish in interface RowReceiver

fail

public void fail(java.lang.Throwable throwable)

Description copied from interface: RowReceiver

Is called from the upstream in case of a failure. This is the equivalent to finish and indicates that the upstream is finished

Specified by:

fail in interface RowReceiver

Parameters:

throwable - the cause of the fail NOTE: This method must not throw any exceptions!

kill

public void kill(java.lang.Throwable throwable)

Description copied from interface: RowReceiver

kill a RowReceiver to stop it's execution. kill can be called from a different thread and can be called after/during finish/fail operations If a RowReceiver doesn't delegate the kill to another RowReceiver the rowReceiver has to return false on the next setNextRow call in order to stop collect operations.

Specified by:

kill in interface RowReceiver

prepare

public void prepare()

Description copied from interface: RowReceiver

prepares / starts the RowReceiver, after this call it must be ready to receive rows

Specified by:

prepare in interface RowReceiver

requirements

public java.util.Set<Requirement> requirements()

Description copied from interface: RowReceiver

specifies which requirements a downstream requires from an upstream in order to work correctly. This can be used to switch to optimized implementations if something isn't/is requirement

Specified by:

requirements in interface RowReceiver

setUpstream

public void setUpstream(RowUpstream rowUpstream)

Description copied from interface: RowReceiver

an RowUpstream who wants to call RowReceiver.setNextRow(Row) calls setUpstream before he starts sending rows so that the RowReceiver can call pause/resume on the upstream.

Specified by:

setUpstream in interface RowReceiver