/*	$NetBSD: rf_sstf.h,v 1.1 1998/11/13 04:20:34 oster Exp $	*/
/*
 * Copyright (c) 1995 Carnegie-Mellon University.
 * All rights reserved.
 *
 * Author: Jim Zelenka
 *
 * Permission to use, copy, modify and distribute this software and
 * its documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 *
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 *
 * Carnegie Mellon requests users of this software to return to
 *
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 *
 * any improvements or extensions that they make and grant Carnegie the
 * rights to redistribute these changes.
 */

/* :  
 * Log: rf_sstf.h,v 
 * Revision 1.6  1996/06/18 20:53:11  jimz
 * fix up disk queueing (remove configure routine,
 * add shutdown list arg to create routines)
 *
 * Revision 1.5  1996/06/13  20:42:08  jimz
 * add scan, cscan
 *
 * Revision 1.4  1996/06/07  22:26:27  jimz
 * type-ify which_ru (RF_ReconUnitNum_t)
 *
 * Revision 1.3  1996/06/07  21:33:04  jimz
 * begin using consistent types for sector numbers,
 * stripe numbers, row+col numbers, recon unit numbers
 *
 * Revision 1.2  1996/06/06  01:22:24  jimz
 * minor cleanup
 *
 * Revision 1.1  1996/06/05  19:17:40  jimz
 * Initial revision
 *
 */

#ifndef _RF__RF_SSTF_H_
#define _RF__RF_SSTF_H_

#include "rf_diskqueue.h"

typedef struct RF_SstfQ_s {
	RF_DiskQueueData_t  *queue;
	RF_DiskQueueData_t  *qtail;
	int                  qlen;
} RF_SstfQ_t;

typedef struct RF_Sstf_s {
	RF_SstfQ_t        left;
	RF_SstfQ_t        right;
	RF_SstfQ_t        lopri;
	RF_SectorNum_t    last_sector;
	int               dir;
	int               allow_reverse;
} RF_Sstf_t;

void *rf_SstfCreate(RF_SectorCount_t sect_per_disk,
	RF_AllocListElem_t *cl_list, RF_ShutdownList_t **listp);
void *rf_ScanCreate(RF_SectorCount_t sect_per_disk,
	RF_AllocListElem_t *cl_list, RF_ShutdownList_t **listp);
void *rf_CscanCreate(RF_SectorCount_t sect_per_disk,
	RF_AllocListElem_t *cl_list, RF_ShutdownList_t **listp);
void rf_SstfEnqueue(void *qptr, RF_DiskQueueData_t *req, int priority);
RF_DiskQueueData_t *rf_SstfDequeue(void *qptr);
RF_DiskQueueData_t *rf_SstfPeek(void *qptr);
int rf_SstfPromote(void *qptr, RF_StripeNum_t parityStripeID,
	RF_ReconUnitNum_t which_ru);
RF_DiskQueueData_t *rf_ScanDequeue(void *qptr);
RF_DiskQueueData_t *rf_ScanPeek(void *qptr);
RF_DiskQueueData_t *rf_CscanDequeue(void *qptr);
RF_DiskQueueData_t *rf_CscanPeek(void *qptr);

#endif /* !_RF__RF_SSTF_H_ */