ChannelOutboundBuffer (Netty API Reference (4.1.115.Final))

java.lang.Object
- io.netty.channel.ChannelOutboundBuffer

```
public final class ChannelOutboundBuffer
extends Object
```
(Transport implementors only) an internal data structure used by AbstractChannel to store its pending outbound write requests.
All methods must be called by a transport implementation from an I/O thread, except the following ones:
- isWritable()
- getUserDefinedWritability(int) and setUserDefinedWritability(int, boolean)

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static interface ChannelOutboundBuffer.MessageProcessor

Nested Classes
Modifier and Type	Class and Description
`static interface`	`ChannelOutboundBuffer.MessageProcessor`

Method Summary

All Methods Instance Methods Concrete Methods Deprecated Methods
Modifier and Type	Method and Description
`void`	`addFlush()` Add a flush to this `ChannelOutboundBuffer`.
`void`	`addMessage(Object msg, int size, ChannelPromise promise)` Add given message to this `ChannelOutboundBuffer`.
`long`	`bytesBeforeUnwritable()` Get how many bytes can be written until `isWritable()` returns `false`.
`long`	`bytesBeforeWritable()` Get how many bytes must be drained from the underlying buffer until `isWritable()` returns `true`.
`Object`	`current()` Return the current message to write or `null` if nothing was flushed before and so is ready to be written.
`long`	`currentProgress()` Return the current message flush progress.
`void`	`forEachFlushedMessage(ChannelOutboundBuffer.MessageProcessor processor)` Call `ChannelOutboundBuffer.MessageProcessor.processMessage(Object)` for each flushed message in this `ChannelOutboundBuffer` until `ChannelOutboundBuffer.MessageProcessor.processMessage(Object)` returns `false` or there are no more flushed messages to process.
`boolean`	`getUserDefinedWritability(int index)` Returns `true` if and only if the user-defined writability flag at the specified index is set to `true`.
`boolean`	`isEmpty()` Returns `true` if there are flushed messages in this `ChannelOutboundBuffer` or `false` otherwise.
`boolean`	`isWritable()` Returns `true` if and only if the total number of pending bytes did not exceed the write watermark of the `Channel` and no user-defined writability flag has been set to `false`.
`int`	`nioBufferCount()` Returns the number of `ByteBuffer` that can be written out of the `ByteBuffer` array that was obtained via `nioBuffers()`.
`ByteBuffer[]`	`nioBuffers()` Returns an array of direct NIO buffers if the currently pending messages are made of `ByteBuf` only.
`ByteBuffer[]`	`nioBuffers(int maxCount, long maxBytes)` Returns an array of direct NIO buffers if the currently pending messages are made of `ByteBuf` only.
`long`	`nioBufferSize()` Returns the number of bytes that can be written out of the `ByteBuffer` array that was obtained via `nioBuffers()`.
`void`	`progress(long amount)` Notify the `ChannelPromise` of the current message about writing progress.
`void`	`recycle()` Deprecated.
`boolean`	`remove()` Will remove the current message, mark its `ChannelPromise` as success and return `true`.
`boolean`	`remove(Throwable cause)` Will remove the current message, mark its `ChannelPromise` as failure using the given `Throwable` and return `true`.
`void`	`removeBytes(long writtenBytes)` Removes the fully written entries and update the reader index of the partially written entry.
`void`	`setUserDefinedWritability(int index, boolean writable)` Sets a user-defined writability flag at the specified index.
`int`	`size()` Returns the number of flushed messages in this `ChannelOutboundBuffer`.
`long`	`totalPendingWriteBytes()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Method Detail
  - addMessage
```
public void addMessage(Object msg,
                       int size,
                       ChannelPromise promise)
```
    Add given message to this ChannelOutboundBuffer. The given ChannelPromise will be notified once the message was written.
  - addFlush
```
public void addFlush()
```
    Add a flush to this ChannelOutboundBuffer. This means all previous added messages are marked as flushed and so you will be able to handle them.
  - current
```
public Object current()
```
    Return the current message to write or null if nothing was flushed before and so is ready to be written.
  - currentProgress
```
public long currentProgress()
```
    Return the current message flush progress.
    
    Returns:
    
    0 if nothing was flushed before for the current message or there is no current message
  - progress
```
public void progress(long amount)
```
    Notify the ChannelPromise of the current message about writing progress.
  - remove
```
public boolean remove()
```
    Will remove the current message, mark its ChannelPromise as success and return true. If no flushed message exists at the time this method is called it will return false to signal that no more messages are ready to be handled.
  - remove
```
public boolean remove(Throwable cause)
```
    Will remove the current message, mark its ChannelPromise as failure using the given Throwable and return true. If no flushed message exists at the time this method is called it will return false to signal that no more messages are ready to be handled.
  - removeBytes
```
public void removeBytes(long writtenBytes)
```
    Removes the fully written entries and update the reader index of the partially written entry. This operation assumes all messages in this buffer is ByteBuf.
  - nioBuffers
```
public ByteBuffer[] nioBuffers()
```
    Returns an array of direct NIO buffers if the currently pending messages are made of ByteBuf only. nioBufferCount() and nioBufferSize() will return the number of NIO buffers in the returned array and the total number of readable bytes of the NIO buffers respectively.
    Note that the returned array is reused and thus should not escape AbstractChannel.doWrite(ChannelOutboundBuffer). Refer to NioSocketChannel.doWrite(ChannelOutboundBuffer) for an example.
  - nioBuffers
```
public ByteBuffer[] nioBuffers(int maxCount,
                               long maxBytes)
```
    Returns an array of direct NIO buffers if the currently pending messages are made of ByteBuf only. nioBufferCount() and nioBufferSize() will return the number of NIO buffers in the returned array and the total number of readable bytes of the NIO buffers respectively.
    Note that the returned array is reused and thus should not escape AbstractChannel.doWrite(ChannelOutboundBuffer). Refer to NioSocketChannel.doWrite(ChannelOutboundBuffer) for an example.
    
    Parameters:
    
    maxCount - The maximum amount of buffers that will be added to the return value.
    
    maxBytes - A hint toward the maximum number of bytes to include as part of the return value. Note that this value maybe exceeded because we make a best effort to include at least 1 ByteBuffer in the return value to ensure write progress is made.
  - nioBufferCount
```
public int nioBufferCount()
```
    Returns the number of ByteBuffer that can be written out of the ByteBuffer array that was obtained via nioBuffers(). This method MUST be called after nioBuffers() was called.
  - nioBufferSize
```
public long nioBufferSize()
```
    Returns the number of bytes that can be written out of the ByteBuffer array that was obtained via nioBuffers(). This method MUST be called after nioBuffers() was called.
  - isWritable
```
public boolean isWritable()
```
    Returns true if and only if the total number of pending bytes did not exceed the write watermark of the Channel and no user-defined writability flag has been set to false.
  - getUserDefinedWritability
```
public boolean getUserDefinedWritability(int index)
```
    Returns true if and only if the user-defined writability flag at the specified index is set to true.
  - setUserDefinedWritability
```
public void setUserDefinedWritability(int index,
                                      boolean writable)
```
    Sets a user-defined writability flag at the specified index.
  - size
```
public int size()
```
    Returns the number of flushed messages in this ChannelOutboundBuffer.
  - isEmpty
```
public boolean isEmpty()
```
    Returns true if there are flushed messages in this ChannelOutboundBuffer or false otherwise.
  - recycle
```
@Deprecated
public void recycle()
```
    Deprecated.
  - totalPendingWriteBytes
```
public long totalPendingWriteBytes()
```
  - bytesBeforeUnwritable
```
public long bytesBeforeUnwritable()
```
    Get how many bytes can be written until isWritable() returns false. This quantity will always be non-negative. If isWritable() is false then 0.
  - bytesBeforeWritable
```
public long bytesBeforeWritable()
```
    Get how many bytes must be drained from the underlying buffer until isWritable() returns true. This quantity will always be non-negative. If isWritable() is true then 0.
  - forEachFlushedMessage
```
public void forEachFlushedMessage(ChannelOutboundBuffer.MessageProcessor processor)
                           throws Exception
```
    Call ChannelOutboundBuffer.MessageProcessor.processMessage(Object) for each flushed message in this ChannelOutboundBuffer until ChannelOutboundBuffer.MessageProcessor.processMessage(Object) returns false or there are no more flushed messages to process.
    
    Throws:
    
    Exception

Class ChannelOutboundBuffer

Nested Class Summary

Method Summary

Methods inherited from class java.lang.Object

Method Detail

addMessage

addFlush

current

currentProgress

progress

remove

remove

removeBytes

nioBuffers

nioBuffers

nioBufferCount

nioBufferSize

isWritable

getUserDefinedWritability

setUserDefinedWritability

size

isEmpty

recycle

totalPendingWriteBytes

bytesBeforeUnwritable

bytesBeforeWritable

forEachFlushedMessage