#include "timeout.h"

#include <unistd.h>

#include "error.h"
#include "iopause.h"

/**
  @file timeout.c
  @author djb
  @ref qmail
  @brief read/write timeout handling
  @return same as read(2) or write(2); -1 on error
*/

int timeoutread(int t, int fd, char *buf, int len)
{
  struct taia now;
  struct taia deadline;
  iopause_fd x;

  taia_now(&now);
  taia_uint(&deadline, t);
  taia_add(&deadline, &now, &deadline);

  x.fd = fd;
  x.events = IOPAUSE_READ;
  for (;;) {
    taia_now(&now);
    iopause(&x, 1, &deadline, &now);
    if (x.revents) break;
    if (taia_less(&deadline, &now)) {
      errno = ETIMEDOUT;
      return -1;
    }
  }
  return read(fd, buf, len);
}

int timeoutwrite(int t, int fd, char *buf, int len)
{
  struct taia now;
  struct taia deadline;
  iopause_fd x;

  taia_now(&now);
  taia_uint(&deadline, t);
  taia_add(&deadline, &now, &deadline);

  x.fd = fd;
  x.events = IOPAUSE_WRITE;
  for (;;) {
    taia_now(&now);
    iopause(&x, 1, &deadline, &now);
    if (x.revents) break;
    if (taia_less(&deadline, &now)) {
      errno = ETIMEDOUT;
      return -1;
    }
  }
  return write(fd, buf, len);
}