/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (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 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * Copyright (c) 2014, 2017 by Delphix. All rights reserved.
 */

#ifndef _DMU_ZFETCH_H
#define _DMU_ZFETCH_H

#include <sys/zfs_context.h>

#ifdef  __cplusplus
extern "C" {
#endif

extern uint64_t zfetch_array_rd_sz;

struct dnode;                           /* so we can reference dnode */

typedef struct zfetch {
        krwlock_t       zf_rwlock;      /* protects zfetch structure */
        list_t          zf_stream;      /* list of zstream_t's */
        struct dnode    *zf_dnode;      /* dnode that owns this zfetch */
        int             zf_numstreams;  /* number of zstream_t's */
} zfetch_t;

typedef struct zstream {
        uint64_t        zs_blkid;       /* expect next access at this blkid */
        uint64_t        zs_pf_blkid;    /* next block to prefetch */

        /*
         * We will next prefetch the L1 indirect block of this level-0
         * block id.
         */
        uint64_t        zs_ipf_blkid;

        kmutex_t        zs_lock;        /* protects stream */
        hrtime_t        zs_atime;       /* time last prefetch issued */
        hrtime_t        zs_start_time;  /* start of last prefetch */
        list_node_t     zs_node;        /* link for zf_stream */
        zfetch_t        *zs_fetch;      /* parent fetch */
        zfs_refcount_t  zs_blocks; /* number of pending blocks in the stream */
} zstream_t;

void            zfetch_init(void);
void            zfetch_fini(void);

void            dmu_zfetch_init(zfetch_t *, struct dnode *);
void            dmu_zfetch_fini(zfetch_t *);
void            dmu_zfetch(zfetch_t *, uint64_t, uint64_t, boolean_t,
    boolean_t);


#ifdef  __cplusplus
}
#endif

#endif  /* _DMU_ZFETCH_H */