org.apache.flink.runtime.io.network.api.writer

Class RecordWriter<T extends org.apache.flink.core.io.IOReadableWritable>

java.lang.Object

org.apache.flink.runtime.io.network.api.writer.RecordWriter<T>

Type Parameters:

T - the type of the record that can be emitted with this record writer

public class RecordWriter<T extends org.apache.flink.core.io.IOReadableWritable>
extends Object

A record-oriented runtime result writer.

The RecordWriter wraps the runtime's ResultPartitionWriter and takes care of serializing records into buffers.

Important: it is necessary to call flushAll() after all records have been written with emit(IOReadableWritable). This ensures that all produced records are written to the output stream (incl. partially filled ones).

Field Summary

Fields

Modifier and Type	Field and Description
protected ResultPartitionWriter	targetPartition

Constructor Summary

Constructors

Constructor and Description
RecordWriter(ResultPartitionWriter writer)
RecordWriter(ResultPartitionWriter writer, ChannelSelector<T> channelSelector)
RecordWriter(ResultPartitionWriter writer, ChannelSelector<T> channelSelector, boolean flushAlways)

Method Summary

Modifier and Type	Method and Description
void	broadcastEmit(T record) This is used to broadcast Streaming Watermarks in-band with records.
void	broadcastEvent(AbstractEvent event)
void	clearBuffers()
void	emit(T record)
void	flushAll()
void	randomEmit(T record) This is used to send LatencyMarks to a random target channel.
void	setMetricGroup(TaskIOMetricGroup metrics) Sets the metric group for this RecordWriter.

Methods inherited from class java.lang.Object

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

Field Detail

targetPartition

protected final ResultPartitionWriter targetPartition

Constructor Detail

RecordWriter

public RecordWriter(ResultPartitionWriter writer)

RecordWriter

public RecordWriter(ResultPartitionWriter writer,
                    ChannelSelector<T> channelSelector)

RecordWriter

public RecordWriter(ResultPartitionWriter writer,
                    ChannelSelector<T> channelSelector,
                    boolean flushAlways)

Method Detail

emit

public void emit(T record)
          throws IOException,
                 InterruptedException

Throws:

IOException

InterruptedException

broadcastEmit

public void broadcastEmit(T record)
                   throws IOException,
                          InterruptedException

This is used to broadcast Streaming Watermarks in-band with records. This ignores the ChannelSelector.

Throws:

IOException

InterruptedException

randomEmit

public void randomEmit(T record)
                throws IOException,
                       InterruptedException

This is used to send LatencyMarks to a random target channel.

Throws:

IOException

InterruptedException

broadcastEvent

public void broadcastEvent(AbstractEvent event)
                    throws IOException

Throws:

IOException

flushAll

public void flushAll()

clearBuffers

public void clearBuffers()

setMetricGroup

public void setMetricGroup(TaskIOMetricGroup metrics)

Sets the metric group for this RecordWriter.