/*
 *
 */

 #include <std.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <dos.h>
 #include "request.h"
 #include "globals.h"
 #include "global.h"
 #include "callaspi.h"
 #include "aspi_rw.h"
 #include "rb.h"
 #include "buf.h"
 #include "dmem.h"

/***************************************************************************
 *
 * (...)
 *
 ***************************************************************************/

 struct RB_OBJ *rb_new(rb_list)

 struct RB_OBJ **rb_list;
 {
  long		 size;
  struct RB_OBJ *rb;
  struct RB_OBJ *rb_cur;

  rb_cur = *rb_list;

  size = sizeof(struct RB_OBJ) + sizeof(IO_REQ);
  rb = dmem_alloc(&size);
//  rb = malloc(size);

  if (!rb)
    {
     error("Cannot allocate memory for request structure\n");
     return (NULL);
     }
  else
    {
     rb->tag       = 0L;
     rb->pattern   = PATTERN_NULL;
     rb->issued    = FALSE;
     rb->req_size  = size;
     rb->data_size = 0L;
     rb->prev	   = NULL;
     rb->next	   = NULL;

     if (rb_cur)
       {
       /*
	* Move to the end of the list.
	*/

	for (; rb_cur->next; rb_cur = rb_cur->next)
	   ;

	rb_cur->next = rb;
	rb->prev = rb_cur;
	}
     }

  *rb_list = rb;				/* Point to req just added */
  return (rb);
  }

/***************************************************************************
 *
 * (...)
 *
 ***************************************************************************/

 struct RB_OBJ *rb_free(rb_list)

 struct RB_OBJ **rb_list;
 {
  struct RB_OBJ *rb_prev,
		*rb_cur,
		*rb_next;

  rb_cur = *rb_list;

  if (!rb_cur)
    {
     error("Attempt to free a nonexistant request object\n");
     return (NULL);
     }

  rb_prev = rb_cur->prev;
  rb_next = rb_cur->next;

  if (rb_cur->data_size)
     error ("Memory pointed to by request object still has a nonzero data size");

  dmem_free(&rb_cur);

  if (rb_prev)
     rb_prev->next = rb_next;
  if (rb_next)
     rb_next->prev = rb_prev;

  //
  // After deleting point to up stream request, because of special case:
  // with aspi_poll, where if a request is freed then the search stops
  // even if a request has not been examined yet.
  //

  if (rb_next)
     *rb_list = rb_next;
  else
     *rb_list = rb_prev;

  return (*rb_list);
  }

/***************************************************************************
 *
 * (...)
 *
 ***************************************************************************/

 struct RB_OBJ *rb_first(rb_list)

 struct RB_OBJ **rb_list;
 {
  if (!*rb_list)
     error("NULL request list, cannot go to first request");
  else
    {for (; (*rb_list)->prev; *rb_list = (*rb_list)->prev)
	;
     }

  return (*rb_list);
  }

/***************************************************************************
 *
 * (...)
 *
 ***************************************************************************/

 struct RB_OBJ *rb_next(rb_list)

 struct RB_OBJ **rb_list;
 {
  struct RB_OBJ *rb_cur;

  rb_cur = *rb_list;

  if (!rb_cur)
     error("NULL request list, cannot go to next request");
  else
    {
     rb_cur = rb_cur->next;			/* Next req		  */
     if (rb_cur)                                /* Next exists?	   	  */
	*rb_list = rb_cur;                      /* New list pointer	  */
     }

  return (rb_cur);
  }