// -*- C++ -*-
//
// $Id: FIFO_Recv_Msg.inl 82559 2008-08-07 20:23:07Z parsons $

#include "ace/Min_Max.h"
#include "ace/OS_NS_stropts.h"
#include "ace/Truncate.h"

#if !defined (ACE_HAS_STREAM_PIPES)
#include "ace/OS_NS_unistd.h"
#endif

ACE_BEGIN_VERSIONED_NAMESPACE_DECL

ACE_INLINE ssize_t
ACE_FIFO_Recv_Msg::recv (ACE_Str_Buf &recv_msg)
{
  ACE_TRACE ("ACE_FIFO_Recv_Msg::recv");
#if defined (ACE_HAS_STREAM_PIPES)
  int i = 0;
  if (ACE_OS::getmsg (this->get_handle (),
                      (strbuf *) 0,
                      (strbuf *) &recv_msg,
                      &i) == -1)
    {
      return -1;
    }
  else
    {
      return recv_msg.len;
    }
#else /* Do the ol' 2-read trick... */
  if (ACE_OS::read (this->get_handle (),
                    (char *) &recv_msg.len,
                    sizeof recv_msg.len) != sizeof recv_msg.len)
    {
      return -1;
    }
  else
    {
      size_t remaining = static_cast<size_t> (recv_msg.len);
      size_t requested = static_cast<size_t> (recv_msg.maxlen);
      ssize_t recv_len = ACE_OS::read (this->get_handle (),
                                       (char *) recv_msg.buf,
                                       ACE_MIN (remaining, requested));
                                       
      if (recv_len == -1)
        {
          return -1;
        }
        
      // Tell caller what's really in the buffer.
      recv_msg.len = static_cast<int> (recv_len);

      // If there are more bytes remaining in the message, read them and
      // throw them away. Leaving them in the FIFO would make it difficult
      // to find the start of the next message in the fifo.
      // Since the ACE_HAS_STREAM_PIPES version of this method doesn't
      // return getmsg()'s indication of "data remaining", don't worry about
      // saving the indication here either to read the remainder later.
      size_t total_msg_size = remaining;
      remaining -= recv_len;
      
      while (remaining > 0)
        {
          const size_t throw_away = 1024;
          char dev_null[throw_away];
          recv_len = ACE_OS::read (this->get_handle (),
                                   dev_null,
                                   ACE_MIN (remaining, throw_away));
                                   
          if (recv_len == -1)
            {
              break;
            }
            
          remaining -= recv_len;
        }
        
      return ACE_Utils::truncate_cast<ssize_t> (total_msg_size);
    }
#endif /* ACE_HAS_STREAM_PIPES */
}

ACE_INLINE ssize_t
ACE_FIFO_Recv_Msg::recv (void *buf, size_t max_len)
{
  ACE_TRACE ("ACE_FIFO_Recv_Msg::recv");
  ACE_Str_Buf recv_msg ((char *) buf, 0, static_cast<int> (max_len));

  return this->recv (recv_msg);
}

#if defined (ACE_HAS_STREAM_PIPES)
ACE_INLINE ssize_t
ACE_FIFO_Recv_Msg::recv (ACE_Str_Buf *data,
                         ACE_Str_Buf *cntl,
                         int *flags)
{
  ACE_TRACE ("ACE_FIFO_Recv_Msg::recv");
  if (ACE_OS::getmsg (this->get_handle (),
                      (strbuf *) cntl,
                      (strbuf *) data,
                      flags) == -1)
    {
      return -1;
    }
  else
    {
      return (cntl == 0 ? 0 : cntl->len) + (data == 0 ? 0 : data->len);
    }
}

ACE_INLINE ssize_t
ACE_FIFO_Recv_Msg::recv (int *band,
                         ACE_Str_Buf *data,
                         ACE_Str_Buf *cntl,
                         int *flags)
{
  ACE_TRACE ("ACE_FIFO_Recv_Msg::recv");
  
  if (ACE_OS::getpmsg (this->get_handle (),
                       (strbuf *) cntl,
                       (strbuf *) data,
                       band,
                       flags) == -1)
    {
      return -1;
    }
  else
    {
      return (cntl == 0 ? 0 : cntl->len) + (data == 0 ? 0 : data->len);
    }
}
#endif /* ACE_HAS_STREAM_PIPES */

ACE_END_VERSIONED_NAMESPACE_DECL
