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

All Implemented Interfaces:

AvailabilityProvider

Direct Known Subclasses:

BroadcastRecordWriter, ChannelSelectorRecordWriter

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

An abstract record-oriented runtime result writer.

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

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.flink.runtime.io.AvailabilityProvider

AvailabilityProvider.AvailabilityHelper

Field Summary

Fields

Modifier and Type	Field and Description
static String	DEFAULT_OUTPUT_FLUSH_THREAD_NAME Default name for the output flush thread, if no name with a task reference is given.
protected boolean	flushAlways
protected int	numberOfChannels
protected Random	rng
protected org.apache.flink.core.memory.DataOutputSerializer	serializer
protected ResultPartitionWriter	targetPartition

Fields inherited from interface org.apache.flink.runtime.io.AvailabilityProvider

AVAILABLE

Method Summary

Modifier and Type	Method and Description
abstract void	broadcastEmit(T record) This is used to broadcast streaming Watermarks in-band with records.
void	broadcastEvent(AbstractEvent event)
void	broadcastEvent(AbstractEvent event, boolean isPriorityEvent)
protected void	checkErroneous()
void	close() Closes the writer.
abstract void	emit(T record) This is used to send regular records.
protected void	emit(T record, int targetSubpartition)
void	flushAll()
CompletableFuture<?>	getAvailableFuture()
void	randomEmit(T record) This is used to send LatencyMarks to a random target channel.
static ByteBuffer	serializeRecord(org.apache.flink.core.memory.DataOutputSerializer serializer, org.apache.flink.core.io.IOReadableWritable record)
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

Methods inherited from interface org.apache.flink.runtime.io.AvailabilityProvider

and, isApproximatelyAvailable, isAvailable, or

Field Detail

DEFAULT_OUTPUT_FLUSH_THREAD_NAME

@VisibleForTesting
public static final String DEFAULT_OUTPUT_FLUSH_THREAD_NAME

Default name for the output flush thread, if no name with a task reference is given.

See Also:

Constant Field Values

targetPartition

protected final ResultPartitionWriter targetPartition

numberOfChannels

protected final int numberOfChannels

serializer

protected final org.apache.flink.core.memory.DataOutputSerializer serializer

rng

protected final Random rng

flushAlways

protected final boolean flushAlways

Method Detail

emit

protected void emit(T record,
                    int targetSubpartition)
             throws IOException

Throws:

IOException

broadcastEvent

public void broadcastEvent(AbstractEvent event)
                    throws IOException

Throws:

IOException

broadcastEvent

public void broadcastEvent(AbstractEvent event,
                           boolean isPriorityEvent)
                    throws IOException

Throws:

IOException

serializeRecord

@VisibleForTesting
public static ByteBuffer serializeRecord(org.apache.flink.core.memory.DataOutputSerializer serializer,
                                                            org.apache.flink.core.io.IOReadableWritable record)
                                                     throws IOException

Throws:

IOException

flushAll

public void flushAll()

setMetricGroup

public void setMetricGroup(TaskIOMetricGroup metrics)

Sets the metric group for this RecordWriter.

getAvailableFuture

public CompletableFuture<?> getAvailableFuture()

Specified by:

getAvailableFuture in interface AvailabilityProvider

Returns:

a future that is completed if the respective provider is available.

emit

public abstract void emit(T record)
                   throws IOException

This is used to send regular records.

Throws:

IOException

randomEmit

public void randomEmit(T record)
                throws IOException

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

Throws:

IOException

broadcastEmit

public abstract void broadcastEmit(T record)
                            throws IOException

This is used to broadcast streaming Watermarks in-band with records.

Throws:

IOException

close

public void close()

Closes the writer. This stops the flushing thread (if there is one).

checkErroneous

protected void checkErroneous()
                       throws IOException

Throws:

IOException