FreeBSD/Linux Kernel Cross Reference
sys/contrib/openzfs/include/sys/range_tree.h

     /*
      * 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 https://opensource.org/licenses/CDDL-1.0.
     * 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) 2013, 2019 by Delphix. All rights reserved.
     */
    
    #ifndef _SYS_RANGE_TREE_H
    #define _SYS_RANGE_TREE_H
    
    #include <sys/btree.h>
    #include <sys/dmu.h>
    
    #ifdef  __cplusplus
    extern "C" {
    #endif
    
    #define RANGE_TREE_HISTOGRAM_SIZE       64
    
    typedef struct range_tree_ops range_tree_ops_t;
    
    typedef enum range_seg_type {
            RANGE_SEG32,
            RANGE_SEG64,
            RANGE_SEG_GAP,
            RANGE_SEG_NUM_TYPES,
    } range_seg_type_t;
    
    /*
     * Note: the range_tree may not be accessed concurrently; consumers
     * must provide external locking if required.
     */
    typedef struct range_tree {
            zfs_btree_t     rt_root;        /* offset-ordered segment b-tree */
            uint64_t        rt_space;       /* sum of all segments in the map */
            range_seg_type_t rt_type;       /* type of range_seg_t in use */
            /*
             * All data that is stored in the range tree must have a start higher
             * than or equal to rt_start, and all sizes and offsets must be
             * multiples of 1 << rt_shift.
             */
            uint8_t         rt_shift;
            uint64_t        rt_start;
            const range_tree_ops_t *rt_ops;
            void            *rt_arg;
            uint64_t        rt_gap;         /* allowable inter-segment gap */
    
            /*
             * The rt_histogram maintains a histogram of ranges. Each bucket,
             * rt_histogram[i], contains the number of ranges whose size is:
             * 2^i <= size of range in bytes < 2^(i+1)
             */
            uint64_t        rt_histogram[RANGE_TREE_HISTOGRAM_SIZE];
    } range_tree_t;
    
    typedef struct range_seg32 {
            uint32_t        rs_start;       /* starting offset of this segment */
            uint32_t        rs_end;         /* ending offset (non-inclusive) */
    } range_seg32_t;
    
    /*
     * Extremely large metaslabs, vdev-wide trees, and dnode-wide trees may
     * require 64-bit integers for ranges.
     */
    typedef struct range_seg64 {
            uint64_t        rs_start;       /* starting offset of this segment */
            uint64_t        rs_end;         /* ending offset (non-inclusive) */
    } range_seg64_t;
    
    typedef struct range_seg_gap {
            uint64_t        rs_start;       /* starting offset of this segment */
            uint64_t        rs_end;         /* ending offset (non-inclusive) */
            uint64_t        rs_fill;        /* actual fill if gap mode is on */
    } range_seg_gap_t;
    
    /*
     * This type needs to be the largest of the range segs, since it will be stack
    * allocated and then cast the actual type to do tree operations.
    */
   typedef range_seg_gap_t range_seg_max_t;
   
   /*
    * This is just for clarity of code purposes, so we can make it clear that a
    * pointer is to a range seg of some type; when we need to do the actual math,
    * we'll figure out the real type.
    */
   typedef void range_seg_t;
   
   struct range_tree_ops {
           void    (*rtop_create)(range_tree_t *rt, void *arg);
           void    (*rtop_destroy)(range_tree_t *rt, void *arg);
           void    (*rtop_add)(range_tree_t *rt, void *rs, void *arg);
           void    (*rtop_remove)(range_tree_t *rt, void *rs, void *arg);
           void    (*rtop_vacate)(range_tree_t *rt, void *arg);
   };
   
   static inline uint64_t
   rs_get_start_raw(const range_seg_t *rs, const range_tree_t *rt)
   {
           ASSERT3U(rt->rt_type, <=, RANGE_SEG_NUM_TYPES);
           switch (rt->rt_type) {
           case RANGE_SEG32:
                   return (((const range_seg32_t *)rs)->rs_start);
           case RANGE_SEG64:
                   return (((const range_seg64_t *)rs)->rs_start);
           case RANGE_SEG_GAP:
                   return (((const range_seg_gap_t *)rs)->rs_start);
           default:
                   VERIFY(0);
                   return (0);
           }
   }
   
   static inline uint64_t
   rs_get_end_raw(const range_seg_t *rs, const range_tree_t *rt)
   {
           ASSERT3U(rt->rt_type, <=, RANGE_SEG_NUM_TYPES);
           switch (rt->rt_type) {
           case RANGE_SEG32:
                   return (((const range_seg32_t *)rs)->rs_end);
           case RANGE_SEG64:
                   return (((const range_seg64_t *)rs)->rs_end);
           case RANGE_SEG_GAP:
                   return (((const range_seg_gap_t *)rs)->rs_end);
           default:
                   VERIFY(0);
                   return (0);
           }
   }
   
   static inline uint64_t
   rs_get_fill_raw(const range_seg_t *rs, const range_tree_t *rt)
   {
           ASSERT3U(rt->rt_type, <=, RANGE_SEG_NUM_TYPES);
           switch (rt->rt_type) {
           case RANGE_SEG32: {
                   const range_seg32_t *r32 = (const range_seg32_t *)rs;
                   return (r32->rs_end - r32->rs_start);
           }
           case RANGE_SEG64: {
                   const range_seg64_t *r64 = (const range_seg64_t *)rs;
                   return (r64->rs_end - r64->rs_start);
           }
           case RANGE_SEG_GAP:
                   return (((const range_seg_gap_t *)rs)->rs_fill);
           default:
                   VERIFY(0);
                   return (0);
           }
   
   }
   
   static inline uint64_t
   rs_get_start(const range_seg_t *rs, const range_tree_t *rt)
   {
           return ((rs_get_start_raw(rs, rt) << rt->rt_shift) + rt->rt_start);
   }
   
   static inline uint64_t
   rs_get_end(const range_seg_t *rs, const range_tree_t *rt)
   {
           return ((rs_get_end_raw(rs, rt) << rt->rt_shift) + rt->rt_start);
   }
   
   static inline uint64_t
   rs_get_fill(const range_seg_t *rs, const range_tree_t *rt)
   {
           return (rs_get_fill_raw(rs, rt) << rt->rt_shift);
   }
   
   static inline void
   rs_set_start_raw(range_seg_t *rs, range_tree_t *rt, uint64_t start)
   {
           ASSERT3U(rt->rt_type, <=, RANGE_SEG_NUM_TYPES);
           switch (rt->rt_type) {
           case RANGE_SEG32:
                   ASSERT3U(start, <=, UINT32_MAX);
                   ((range_seg32_t *)rs)->rs_start = (uint32_t)start;
                   break;
           case RANGE_SEG64:
                   ((range_seg64_t *)rs)->rs_start = start;
                   break;
           case RANGE_SEG_GAP:
                   ((range_seg_gap_t *)rs)->rs_start = start;
                   break;
           default:
                   VERIFY(0);
           }
   }
   
   static inline void
   rs_set_end_raw(range_seg_t *rs, range_tree_t *rt, uint64_t end)
   {
           ASSERT3U(rt->rt_type, <=, RANGE_SEG_NUM_TYPES);
           switch (rt->rt_type) {
           case RANGE_SEG32:
                   ASSERT3U(end, <=, UINT32_MAX);
                   ((range_seg32_t *)rs)->rs_end = (uint32_t)end;
                   break;
           case RANGE_SEG64:
                   ((range_seg64_t *)rs)->rs_end = end;
                   break;
           case RANGE_SEG_GAP:
                   ((range_seg_gap_t *)rs)->rs_end = end;
                   break;
           default:
                   VERIFY(0);
           }
   }
   
   static inline void
   rs_set_fill_raw(range_seg_t *rs, range_tree_t *rt, uint64_t fill)
   {
           ASSERT3U(rt->rt_type, <=, RANGE_SEG_NUM_TYPES);
           switch (rt->rt_type) {
           case RANGE_SEG32:
                   /* fall through */
           case RANGE_SEG64:
                   ASSERT3U(fill, ==, rs_get_end_raw(rs, rt) - rs_get_start_raw(rs,
                       rt));
                   break;
           case RANGE_SEG_GAP:
                   ((range_seg_gap_t *)rs)->rs_fill = fill;
                   break;
           default:
                   VERIFY(0);
           }
   }
   
   static inline void
   rs_set_start(range_seg_t *rs, range_tree_t *rt, uint64_t start)
   {
           ASSERT3U(start, >=, rt->rt_start);
           ASSERT(IS_P2ALIGNED(start, 1ULL << rt->rt_shift));
           rs_set_start_raw(rs, rt, (start - rt->rt_start) >> rt->rt_shift);
   }
   
   static inline void
   rs_set_end(range_seg_t *rs, range_tree_t *rt, uint64_t end)
   {
           ASSERT3U(end, >=, rt->rt_start);
           ASSERT(IS_P2ALIGNED(end, 1ULL << rt->rt_shift));
           rs_set_end_raw(rs, rt, (end - rt->rt_start) >> rt->rt_shift);
   }
   
   static inline void
   rs_set_fill(range_seg_t *rs, range_tree_t *rt, uint64_t fill)
   {
           ASSERT(IS_P2ALIGNED(fill, 1ULL << rt->rt_shift));
           rs_set_fill_raw(rs, rt, fill >> rt->rt_shift);
   }
   
   typedef void range_tree_func_t(void *arg, uint64_t start, uint64_t size);
   
   range_tree_t *range_tree_create_gap(const range_tree_ops_t *ops,
       range_seg_type_t type, void *arg, uint64_t start, uint64_t shift,
       uint64_t gap);
   range_tree_t *range_tree_create(const range_tree_ops_t *ops,
       range_seg_type_t type, void *arg, uint64_t start, uint64_t shift);
   void range_tree_destroy(range_tree_t *rt);
   boolean_t range_tree_contains(range_tree_t *rt, uint64_t start, uint64_t size);
   range_seg_t *range_tree_find(range_tree_t *rt, uint64_t start, uint64_t size);
   boolean_t range_tree_find_in(range_tree_t *rt, uint64_t start, uint64_t size,
       uint64_t *ostart, uint64_t *osize);
   void range_tree_verify_not_present(range_tree_t *rt,
       uint64_t start, uint64_t size);
   void range_tree_resize_segment(range_tree_t *rt, range_seg_t *rs,
       uint64_t newstart, uint64_t newsize);
   uint64_t range_tree_space(range_tree_t *rt);
   uint64_t range_tree_numsegs(range_tree_t *rt);
   boolean_t range_tree_is_empty(range_tree_t *rt);
   void range_tree_swap(range_tree_t **rtsrc, range_tree_t **rtdst);
   void range_tree_stat_verify(range_tree_t *rt);
   uint64_t range_tree_min(range_tree_t *rt);
   uint64_t range_tree_max(range_tree_t *rt);
   uint64_t range_tree_span(range_tree_t *rt);
   
   void range_tree_add(void *arg, uint64_t start, uint64_t size);
   void range_tree_remove(void *arg, uint64_t start, uint64_t size);
   void range_tree_remove_fill(range_tree_t *rt, uint64_t start, uint64_t size);
   void range_tree_adjust_fill(range_tree_t *rt, range_seg_t *rs, int64_t delta);
   void range_tree_clear(range_tree_t *rt, uint64_t start, uint64_t size);
   
   void range_tree_vacate(range_tree_t *rt, range_tree_func_t *func, void *arg);
   void range_tree_walk(range_tree_t *rt, range_tree_func_t *func, void *arg);
   range_seg_t *range_tree_first(range_tree_t *rt);
   
   void range_tree_remove_xor_add_segment(uint64_t start, uint64_t end,
       range_tree_t *removefrom, range_tree_t *addto);
   void range_tree_remove_xor_add(range_tree_t *rt, range_tree_t *removefrom,
       range_tree_t *addto);
   
   #ifdef  __cplusplus
   }
   #endif
   
   #endif  /* _SYS_RANGE_TREE_H */

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