Package io.netty.channel.unix

Class IovArray

java.lang.Object

io.netty.channel.unix.IovArray

All Implemented Interfaces:

ChannelOutboundBuffer.MessageProcessor

public final class IovArray
extends java.lang.Object
implements ChannelOutboundBuffer.MessageProcessor

Represent an array of struct array and so can be passed directly over via JNI without the need to do any more array copies. The buffers are written out directly into direct memory to match the struct iov. See also man writev.

 struct iovec {
   void  *iov_base;
   size_t iov_len;
 };
 

See also Efficient JNI programming IV: Wrapping native data objects.

Field Summary

Fields

Modifier and Type	Field	Description
static int	IOV_SIZE	The size of an iovec struct in bytes.

Constructor Summary

Constructors

Constructor	Description
IovArray()
IovArray(ByteBuf memory)

Method Summary

Modifier and Type	Method	Description
boolean	add(ByteBuf buf)	Deprecated. Use add(ByteBuf, int, int)
boolean	add(ByteBuf buf, int offset, int len)
void	clear()
int	count()	Returns the number if iov entries.
long	maxBytes()	Get the maximum amount of bytes that can be added to this IovArray.
void	maxBytes(long maxBytes)	Set the maximum amount of bytes that can be added to this IovArray via add(ByteBuf, int, int)
long	memoryAddress(int offset)	Returns the memoryAddress for the given offset.
boolean	processMessage(java.lang.Object msg)	Will be called for each flushed message until it either there are no more flushed messages or this method returns false.
void	release()	Release the IovArray.
long	size()	Returns the size in bytes

Methods inherited from class java.lang.Object

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

Field Detail

IOV_SIZE

public static final int IOV_SIZE

The size of an iovec struct in bytes. This is calculated as we have 2 entries each of the size of the address.

Constructor Detail

IovArray

public IovArray()

IovArray

public IovArray(ByteBuf memory)

Method Detail

clear

public void clear()

add

@Deprecated
public boolean add(ByteBuf buf)

Deprecated.

Use add(ByteBuf, int, int)

add

public boolean add(ByteBuf buf,
                   int offset,
                   int len)

count

public int count()

Returns the number if iov entries.

size

public long size()

Returns the size in bytes

maxBytes

public void maxBytes(long maxBytes)

Set the maximum amount of bytes that can be added to this IovArray via add(ByteBuf, int, int)

This will not impact the existing state of the IovArray, and only applies to subsequent calls to add(ByteBuf).

In order to ensure some progress is made at least one ByteBuf will be accepted even if it's size exceeds this value.

Parameters:

maxBytes - the maximum amount of bytes that can be added to this IovArray.

maxBytes

public long maxBytes()

Get the maximum amount of bytes that can be added to this IovArray.

Returns:

the maximum amount of bytes that can be added to this IovArray.

memoryAddress

public long memoryAddress(int offset)

Returns the memoryAddress for the given offset.

release

public void release()

Release the IovArray. Once release further using of it may crash the JVM!

processMessage

public boolean processMessage(java.lang.Object msg)
                       throws java.lang.Exception

Description copied from interface: ChannelOutboundBuffer.MessageProcessor

Will be called for each flushed message until it either there are no more flushed messages or this method returns false.

Specified by:

processMessage in interface ChannelOutboundBuffer.MessageProcessor

Throws:

java.lang.Exception