Package org.apache.druid.frame.processor

Class PartitionedOutputChannel

java.lang.Object

org.apache.druid.frame.processor.PartitionedOutputChannel

public class PartitionedOutputChannel
extends Object

A channel which can contain multiple partitions of data. It is used by SuperSorter currently to write multiple partitions on the same channel. The readable channel provided to the caller is an instance of PartitionedReadableFrameChannel which allows the caller to open a readable channel for the desired partition.

Method Summary

Modifier and Type	Method	Description
void	convertToReadOnly()	Removes the reference to the writableChannel and frameMemoryAllocator from the object, making it more efficient
MemoryAllocator	getFrameMemoryAllocator()	Returns the memory allocator for the writable channel.
Supplier<PartitionedReadableFrameChannel>	getReadableChannelSupplier()	Returns the partitioned readable channel supplier of this pair.
WritableFrameChannel	getWritableChannel()	Returns the writable channel of this pair.
PartitionedOutputChannel	mapWritableChannel(Function<WritableFrameChannel,WritableFrameChannel> mapFn)
static PartitionedOutputChannel	pair(WritableFrameChannel writableChannel, MemoryAllocator frameMemoryAllocator, Supplier<PartitionedReadableFrameChannel> readableChannelSupplier)	Creates a partitioned output channel pair.
PartitionedOutputChannel	readOnly()	Returns a read-only version of this instance.

Methods inherited from class java.lang.Object

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

Method Details

pair

public static PartitionedOutputChannel pair(WritableFrameChannel writableChannel,
 MemoryAllocator frameMemoryAllocator,
 Supplier<PartitionedReadableFrameChannel> readableChannelSupplier)

Creates a partitioned output channel pair.

Parameters:

writableChannel - writable channel for producer

frameMemoryAllocator - memory allocator for producer to use while writing frames to the channel

readableChannelSupplier - partitioned readable channel for consumer. May be called multiple times, so you should wrap this in Suppliers.memoize(com.google.common.base.Supplier<T>) if needed.

getWritableChannel

public WritableFrameChannel getWritableChannel()

Returns the writable channel of this pair. The producer writes to this channel. Throws ISE if the output channel is read only.

getFrameMemoryAllocator

public MemoryAllocator getFrameMemoryAllocator()

Returns the memory allocator for the writable channel. The producer uses this to generate frames for the channel. Throws ISE if the output channel is read only.

getReadableChannelSupplier

public Supplier<PartitionedReadableFrameChannel> getReadableChannelSupplier()

Returns the partitioned readable channel supplier of this pair. The consumer reads from this channel.

mapWritableChannel

public PartitionedOutputChannel mapWritableChannel(Function<WritableFrameChannel,WritableFrameChannel> mapFn)

readOnly

public PartitionedOutputChannel readOnly()

Returns a read-only version of this instance. Read-only versions have neither getWritableChannel() nor getFrameMemoryAllocator(), and therefore require substantially less memory.

convertToReadOnly

public void convertToReadOnly()

Removes the reference to the writableChannel and frameMemoryAllocator from the object, making it more efficient