Messages in this thread | | | Date | Wed, 23 Sep 2009 09:33:24 +0200 | From | Enrik Berkhan <> | Subject | Re: splice between non-pipe (tcp socket) fds |
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Марк Коренберг wrote: > I want splice() to work with two tcp sockets().I think to implement > this. Two questions:
This works already by introducing a pipe between the two:
while (0 < (len = splice(sock1, 0, pipe, 0, max_len, some_flags))) splice(pipe, 0, sock2, 0, len, some_flags);
Just like with read(2) and write(2), but without copy to/from userspace.
> 1. Is any work in this direction? > 2. Why this functionality does not implemented now? any difficulties? > > I think API should consist of 2 main functions: > 1. detach available buffers from fd1 (and save info in some struct) > 2. attach buffers to fd2 (from this struct) > this functions should be called under some lock to guarantee > atomicity. if something happen, return buffers back to original file.
What about full duplex?
> At now, I think that the most quick way to acheive my results, is to > create intermediate temporary pipe inside kernel and splice from > non-pipe fd to pipe, and than from pipe to second non-pipe fd.
Have a look at the "sendfile emulation" in fs/splice.c. Maybe you can generalize that in some way or the other.
Enrik
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