IV_FD_PUMP_INIT, iv_fd_pump_init, iv_fd_pump_destroy, iv_fd_pump_pump, iv_fd_pump_is_done - pump data

iv_fd_pump provides a way for moving data between two file descriptors.

       To set up iv_fd_pump for moving data, call IV_FD_PUMP_INIT on a structiv_fd_pump  object,  fill  in  the
       ->from_fd,->to_fd,->cookie,->set_bands  and  ->flags  members, and then call iv_fd_pump_init on the
       object.

       Conversely, to destroy a structiv_fd_pump object, call iv_fd_pump_destroy.  There are no restrictions on
       when this function can be called.

       A call to iv_fd_pump_pump will attempt to move data from ->from_fd to  ->to_fd  via  an  internal  buffer
       associated with the structiv_fd_pump object.

       During  calls to iv_fd_pump_init,iv_fd_pump_destroy and iv_fd_pump_pump, the callback function specified
       by ->set_bands may be invoked (with ->cookie as its first argument), by which iv_fd_pump indicates  under
       which circumstances it wishes for future invocations of iv_fd_pump_pump to be done.

       If  the  pollin  argument to ->set_bands is true, there is space left in the internal buffer (and we have
       not yet seen an end-of-file condition on input), and so you should call iv_fd_pump_pump again when  there
       is a POLLIN condition on ->from_fd.

       If  the  pollout argument to ->set_bands is true, there is data in the internal buffer that could not all
       be transferred to ->to_fd, and so you should call iv_fd_pump_pump again when there is a POLLOUT condition
       on ->to_fd.

       If IV_FD_PUMP_FLAG_RELAY_EOF is set in ->flags,iv_fd_pump_pump will call  shutdown(2)  on  ->to_fd  with
       SHUT_WR as its second argument upon seeing an end-of-file condition on ->from_fd (but only after all data
       from the internal buffer has been drained into ->to_fd first).

       iv_fd_pump_pump  will return -1 if there was an error, 0 if we're done pumping data (meaning that an end-
       of-file condition was seen on the input file descriptor and that all data in the internal buffer has been
       drained into the output file descriptor), or 1 if there is more data left to be pumped.

       iv_fd_pump_is_done will return a true value if iv_fd_pump_pump has previously returned  0,  otherwise  it
       will return false.

       Internally, iv_fd_pump_pump will use splice(2) if it is available, otherwise it will fall back to read(2)
       and write(2).

       IV_FD_PUMP_INIT,  iv_fd_pump_init,  iv_fd_pump_destroy,  iv_fd_pump_pump,  iv_fd_pump_is_done - pump data
       between file descriptors

ivykis(3), splice(2)

ivykis                                             2012-06-05                                      iv_fd_pump(3)

#include<iv_fd_pump.h>

       struct iv_fd_pump {
               int             from_fd;
               int             to_fd;
               void            *cookie;
               void            (*set_bands)(void *cookie, int pollin, int pollout);
               unsigned int    flags;
       };

       voidIV_FD_PUMP_INIT(structiv_fd_pump*this);voidiv_fd_pump_init(structiv_fd_pump*this);voidiv_fd_pump_destroy(structiv_fd_pump*this);intiv_fd_pump_pump(structiv_fd_pump*this);intiv_fd_pump_is_done(conststructiv_fd_pump*this);