/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#ifndef _SYS_SPACE_MAP_H
#define	_SYS_SPACE_MAP_H

#pragma ident	"%Z%%M%	%I%	%E% SMI"

#include <sys/avl.h>
#include <sys/dmu.h>

#ifdef	__cplusplus
extern "C" {
#endif

typedef struct space_map {
	avl_tree_t	sm_root;	/* Root of the AVL tree */
	uint64_t	sm_start;	/* Start of map (inclusive) */
	uint64_t	sm_end;		/* End of map (exclusive) */
	uint64_t	sm_size;	/* Size of map (end - start) */
	uint64_t	sm_shift;	/* Unit shift */
	uint64_t	sm_space;	/* Sum of all segments in the map */
	kmutex_t	*sm_lock;	/* pointer to lock that protects map */
} space_map_t;

typedef struct space_seg {
	avl_node_t	ss_node;	/* AVL node */
	uint64_t	ss_start;	/* starting offset of this segment */
	uint64_t	ss_end;		/* ending offset (non-inclusive) */
} space_seg_t;

typedef struct space_map_obj {
	uint64_t	smo_object;	/* on-disk space map object */
	uint64_t	smo_objsize;	/* size of the object */
	uint64_t	smo_alloc;	/* space allocated from the map */
} space_map_obj_t;

/*
 * debug entry
 *
 *    1      3         10                     50
 *  ,---+--------+------------+---------------------------------.
 *  | 1 | action |  syncpass  |        txg (lower bits)         |
 *  `---+--------+------------+---------------------------------'
 *   63  62    60 59        50 49                               0
 *
 *
 *
 * non-debug entry
 *
 *    1               47                   1           15
 *  ,-----------------------------------------------------------.
 *  | 0 |   offset (sm_shift units)    | type |       run       |
 *  `-----------------------------------------------------------'
 *   63  62                          17   16   15               0
 */

/* All this stuff takes and returns bytes */
#define	SM_RUN_DECODE(x)	(BF64_DECODE(x, 0, 15) + 1)
#define	SM_RUN_ENCODE(x)	BF64_ENCODE((x) - 1, 0, 15)
#define	SM_TYPE_DECODE(x)	BF64_DECODE(x, 15, 1)
#define	SM_TYPE_ENCODE(x)	BF64_ENCODE(x, 15, 1)
#define	SM_OFFSET_DECODE(x)	BF64_DECODE(x, 16, 47)
#define	SM_OFFSET_ENCODE(x)	BF64_ENCODE(x, 16, 47)
#define	SM_DEBUG_DECODE(x)	BF64_DECODE(x, 63, 1)
#define	SM_DEBUG_ENCODE(x)	BF64_ENCODE(x, 63, 1)

#define	SM_DEBUG_ACTION_DECODE(x)	BF64_DECODE(x, 60, 3)
#define	SM_DEBUG_ACTION_ENCODE(x)	BF64_ENCODE(x, 60, 3)

#define	SM_DEBUG_SYNCPASS_DECODE(x)	BF64_DECODE(x, 50, 10)
#define	SM_DEBUG_SYNCPASS_ENCODE(x)	BF64_ENCODE(x, 50, 10)

#define	SM_DEBUG_TXG_DECODE(x)		BF64_DECODE(x, 0, 50)
#define	SM_DEBUG_TXG_ENCODE(x)		BF64_ENCODE(x, 0, 50)

#define	SM_RUN_MAX			SM_RUN_DECODE(~0ULL)

#define	SM_ALLOC	0x0
#define	SM_FREE		0x1

/*
 * The data for a given space map can be kept on blocks of any size.
 * Larger blocks entail fewer i/o operations, but they also cause the
 * DMU to keep more data in-core, and also to waste more i/o bandwidth
 * when only a few blocks have changed since the last transaction group.
 * This could use a lot more research, but for now, set the freelist
 * block size to 4k (2^12).
 */
#define	SPACE_MAP_BLOCKSHIFT	12

#define	SPACE_MAP_CHUNKSIZE	(1<<20)

typedef void space_map_func_t(space_map_t *sm, uint64_t start, uint64_t size);

extern void space_map_create(space_map_t *sm, uint64_t start, uint64_t size,
    uint64_t shift, kmutex_t *lp);
extern void space_map_destroy(space_map_t *sm);
extern void space_map_add(space_map_t *sm, uint64_t start, uint64_t size);
extern void space_map_remove(space_map_t *sm, uint64_t start, uint64_t size);
extern int space_map_contains(space_map_t *sm, uint64_t start, uint64_t size);
extern void space_map_vacate(space_map_t *sm,
    space_map_func_t *func, space_map_t *mdest);
extern void space_map_iterate(space_map_t *sm,
    space_map_func_t *func, space_map_t *mdest);
extern void space_map_merge(space_map_t *dest, space_map_t *src);
extern void space_map_excise(space_map_t *sm, uint64_t start, uint64_t size);
extern void space_map_union(space_map_t *smd, space_map_t *sms);

extern int space_map_load(space_map_t *sm, space_map_obj_t *smo,
    uint8_t maptype, objset_t *os, uint64_t end, uint64_t space);
extern void space_map_sync(space_map_t *sm, space_map_t *dest,
    space_map_obj_t *smo, uint8_t maptype, objset_t *os, dmu_tx_t *tx);
extern void space_map_write(space_map_t *sm, space_map_obj_t *smo,
    objset_t *os, dmu_tx_t *tx);

#ifdef	__cplusplus
}
#endif

#endif	/* _SYS_SPACE_MAP_H */