Netty 4.1.107.Final · io.netty.channel.CoalescingBufferQueue

A FIFO queue of bytes where producers add bytes by repeatedly adding ByteBuf and consumers take bytes in arbitrary lengths. This allows producers to add lots of small buffers and the consumer to take all the bytes out in a single buffer. Conversely the producer may add larger buffers and the consumer could take the bytes in many small buffers.

Bytes are added and removed with promises. If the last byte of a buffer added with a promise is removed then that promise will complete when the promise passed to remove completes.

This functionality is useful for aggregating or partitioning writes into fixed size buffers for framing protocols such as HTTP2.

Modifier and Type	Field and Description
private final Channel	channel

Constructor Summary

Access	Constructor and Description
public	CoalescingBufferQueue(Channel channel)
public	CoalescingBufferQueue(Channel channel, int initSize)
public	CoalescingBufferQueue(Channel channel, int initSize, boolean updateWritability)

Method Summary

Modifier and Type	Method and Description
protected ByteBuf	compose(ByteBufAllocator alloc, ByteBuf cumulation, ByteBuf next) Implements abstract io.netty.channel.AbstractCoalescingBufferQueue.compose. Calculate the result of `current + next`.
public void	releaseAndFailAll(Throwable cause) Release all buffers in the queue and complete all listeners and promises.
public ByteBuf	Returns: a `ByteBuf` composed of the enqueued buffers. remove(int the maximum number of readable bytes in the returned `ByteBuf`, if `bytes` is greater than `readableBytes` then a buffer of length `readableBytes` is returned. bytes, ChannelPromise used to aggregate the promises and listeners for the constituent buffers. aggregatePromise) Remove a `ByteBuf` from the queue with the specified number of bytes.
protected ByteBuf	removeEmptyValue() Implements abstract io.netty.channel.AbstractCoalescingBufferQueue.removeEmptyValue. The value to return when `remove(ByteBufAllocator, int, ChannelPromise)` is called but the queue is empty.

Inherited from io.netty.channel.AbstractCoalescingBufferQueue:: add add add addFirst composeFirst composeIntoComposite copyAndCompose copyTo isEmpty readableBytes releaseAndFailAll remove removeFirst size toString writeAndRemoveAll

Field Detail

channel	back to summary
private final Channel channel

Constructor Detail

CoalescingBufferQueue	back to summary
public CoalescingBufferQueue(Channel channel)

CoalescingBufferQueue	back to summary
public CoalescingBufferQueue(Channel channel, int initSize)

CoalescingBufferQueue	back to summary
public CoalescingBufferQueue(Channel channel, int initSize, boolean updateWritability)

Method Detail

compose back to summary

compose	back to summary
protected ByteBuf compose(ByteBufAllocator alloc, ByteBuf cumulation, ByteBuf next) Implements abstract io.netty.channel.AbstractCoalescingBufferQueue.compose. Doc from io.netty.channel.AbstractCoalescingBufferQueue.compose. Calculate the result of `current + next`. Annotations @Override

protected ByteBuf compose(ByteBufAllocator alloc, ByteBuf cumulation, ByteBuf next)

Implements abstract io.netty.channel.AbstractCoalescingBufferQueue.compose.

Doc from io.netty.channel.AbstractCoalescingBufferQueue.compose.

Calculate the result of current + next.

Annotations

@Override

releaseAndFailAll	back to summary
public void releaseAndFailAll(Throwable cause) Release all buffers in the queue and complete all listeners and promises.

remove back to summary

remove	back to summary
public ByteBuf remove(int bytes, ChannelPromise aggregatePromise) Remove a `ByteBuf` from the queue with the specified number of bytes. Any added buffer who's bytes are fully consumed during removal will have it's promise completed when the passed aggregate `ChannelPromise` completes. Parameters bytes:int the maximum number of readable bytes in the returned `ByteBuf`, if `bytes` is greater than `readableBytes` then a buffer of length `readableBytes` is returned. aggregatePromise:ChannelPromise used to aggregate the promises and listeners for the constituent buffers. Returns:ByteBuf a `ByteBuf` composed of the enqueued buffers.

public ByteBuf remove(int bytes, ChannelPromise aggregatePromise)

Remove a ByteBuf from the queue with the specified number of bytes. Any added buffer who's bytes are fully consumed during removal will have it's promise completed when the passed aggregate ChannelPromise completes.

Parameters

bytes:int: the maximum number of readable bytes in the returned ByteBuf, if bytes is greater than readableBytes then a buffer of length readableBytes is returned.
aggregatePromise:ChannelPromise: used to aggregate the promises and listeners for the constituent buffers.

Returns:ByteBuf

a ByteBuf composed of the enqueued buffers.

removeEmptyValue back to summary

removeEmptyValue	back to summary
protected ByteBuf removeEmptyValue() Implements abstract io.netty.channel.AbstractCoalescingBufferQueue.removeEmptyValue. Doc from io.netty.channel.AbstractCoalescingBufferQueue.removeEmptyValue. The value to return when `remove(ByteBufAllocator, int, ChannelPromise)` is called but the queue is empty. Returns:ByteBuf the `ByteBuf` which represents an empty queue. Annotations @Override

protected ByteBuf removeEmptyValue()

Implements abstract io.netty.channel.AbstractCoalescingBufferQueue.removeEmptyValue.

Doc from io.netty.channel.AbstractCoalescingBufferQueue.removeEmptyValue.

The value to return when remove(ByteBufAllocator, int, ChannelPromise) is called but the queue is empty.