Using Java to perform Zero Copy data transfers between two or more sockets

Question

Does any one know of any good java libraries/API packages that performs zero copy data transfers between two or more sockets? I know that Java\'s NIO API can perform zero copy d

Answer 1

I don't know much about SocketChannel, but I think ByteBuffer.allocateDirect() is a good choice for you.

Just read socket A's data into ByteBuffer.allocateDirect() and let socket B read from it, simple and easy.

Here's the differences:

1. Old Way

SocketA --> BufferA(Kernel Space) --> BufferB(User Space)

BufferB(User Space) --> BufferC(Kernel Space) --> SocketB

2. Zero Copy Way

SocketA --> DirectBuffer(Could be accessed from Kernel and User Space)

DirectBuffer --> SocketB

Note

IMHO, I don't think we can make it directly SocketA -> SocketB, the os need to load data into physical memory before send them out.

========= EDIT =========

According to the article you referred, FileChannel's transferTo do it this way :

Use ByteBuffer.allocateDirect() you don't need to switch context between Kernel and User space. The only buffer is mapped to physical memory while reading and sending use the same blocks.